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ZHANG Wei, WANG Haihua, WENG Wei, YAO Shuqing, SHAO Mingjuan
2024,51(3):1-8, DOI: 10.12143/j.ztgc.2024.03.001
Abstract:
Geothermal energy is the only base load power among the major renewable energy sources. Hot dry rock （HDR） is a high temperature rock mass buried in the deep earth without connate water or with a little water， which can form an enhanced geothermal system reservoir through hydraulic stimulation， and a considerable amount of geothermal energy can be extracted. There are two main technological challenges associated with the development of HDR geothermal resource， i.e.， very hard rock， such as granite or basalt limits the rate of penetration （ROP）， and the temperature of the drilling system exceeds the operational limits of electronic tools like measurement while drilling （MWD） and steerable rotary tools. In recent years， the Utah FORGE project funded by the U.S. Department of Energy （DOE） provided an opportunity to test new drill bit technology and optimize drilling procedures to deliver a step change in ROP performance and drilling cost reduction. In this paper， the deployment of geothermal drilling technology R&D in the recent development plan of DOE Geothermal Technology Office is reviewed， the application of the redesign workflows based on physical limits in the drilling practice of the Utah project is selective analyzed， and the main areas covered by the multiple plans and projects funded by DOE in terms of geothermal drilling technology as well as the lessons learned from the Utah project in exploring and practicing drilling operation optimization are summarized.
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WANG Zuncha, CHENG Wan, AI Kun, HU Qinghai, SHI Yuzhao
2024,51(3):9-19, DOI: 10.12143/j.ztgc.2024.03.002
Abstract:
With the increasing dependence on foreign oil and gas， unconventional oil and gas energy such as tight oil and gas and shale oil and gas have become the focus of China’s energy development. Well factory fracturing technology is widely used in unconventional oil and gas development because it can reconstruct low-permeability formations， significantly reduce construction costs， shorten construction time， improve equipment and land utilization. Based on the discussion of the development status of well factory fracturing technology， this paper introduces the well pattern deployment characteristics of cluster horizontal wells， such as wellbore direction， length of horizontal sections， wellbore spacing and further statistically analyzes the key technical parameters of horizontal wells in segmented clusters， such as fracture length， cluster spacing and perforating cluster number. Moreover， the fracturing methods commonly used in cluster horizontal well factory fracturing are also introduced， including dual-wells simultaneous fracturing， dual-well zipper fracturing and multi-well combination fracturing， and the advantages and disadvantages of the common fracturing methods are analyzed by contrast. It is suggested that the theories such as prediction of interwell fracture interference and well cluster fracturing perforation cluster design should be developed. The research points out the direction for the development of well fracturing technologies for unconventional oil and gas reservoir in China.
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LIU Yong, ZHOU Ce, ZHAO Yuangang, ZHANG Jiajia, ZHOU Juan
2024,51(3):20-26, DOI: 10.12143/j.ztgc.2024.03.003
Abstract:
Given the critical importance of water cycle variations in extreme ecological environments such as high-altitude and arid regions to national ecological security， there is a pressing need to research on monitoring devices and technologies for key parameters of water cycle. This paper focuses on technical challenges associated with field in-situ/mobile/non-contact， automatic and stable monitoring of key parameters encompassing water cycle. A series of studies have been conducted to explore new technological devices for monitoring these key parameters of soil， air， ice， and snow in ecological systems. By establishing an integrated monitoring system for ecosystems based on the Internet of Things （IoT）， the industry technological barriers are hope to be broken through， and the interdisciplinary collaboration across fields including engineering， geology， and computer science can be fostered. Through collaborative efforts in researching and innovating key parameter monitoring technologies for the water cycle in extreme ecological environments， extensive， all-weather and three-dimensional monitoring of critical ecological functional areas will be achieved. This endeavor will hold significant importance in advancing China’s ecological civilization construction and promoting the comprehensive application and development of ecological monitoring technologies in the country.
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DENG Yingying, SUN Pinghe, CAO Han, YANG Hanhan, LÜ Yan, ZHANG Hangsheng, ZHANG Chen, PU Yingjie
2024,51(3):27-36, DOI: 10.12143/j.ztgc.2024.03.004
Abstract:
Direct push drilling technology has the advantages of no flushing medium， fast speed， small disturbance， etc.， but it is susceptible to the interference of factors such as large differences in the engineering properties of the soil at the site of organic contamination， resulting in tilting of the borehole and other phenomena. Organic pollutants will change the microstructure of the soil， resulting in changes in soil engineering properties， which in turn reduces the accuracy of direct drilling sampling points. Typical organic pollutants toluene and perchloroethylene were selected， and soil samples with different pollutant concentrations （toluene： 75， 120 and 672 mg/kg； perchloroethylene： 11， 53 and 183 mg/kg） were prepared to simulate the drilling encountered with the organically contaminated stratum. XRD， SEM， contact angle and nitrogen adsorption and desorption tests were carried out to investigate the changing rules of microstructure of the soil samples under the influence of different organic pollutant concentrations.The results of the SEM image analysis and nitrogen adsorption and desorption tests showed that： toluene and perchloroethylene encapsulated and chemically damaged soil samples， resulting in the agglomeration of soil particles， the reduction of the specific surface area， the obvious increase in the number of small pores， and the decrease in the pore volume of soil； the content of clay particles was 30.28% at the highest level. The highest clay content of 30.28% in soil sample 2# after 672mg/kg toluene and 183mg/kg tetrachloroethylene contamination， the specific surface area decreased by 30.70% and 33.40%， respectively， and the Pearson''s correlation coefficient of r=0.382 indicates that there is a certain positive correlation between the content of clay particles and the rate of reduction of the specific surface area. Meanwhile， due to the wrapping effect of non-polar molecules toluene and perchloroethylene on the soil particles， the hydrophilic groups of the soil samples were isolated， resulting in the deterioration of the hydrophilicity of the soil samples and the increase of the contact angle. This study suggests that organic pollutants can lead to changes in the microscopic characteristics of the soil， which ultimately leads to an increase in the non-homogeneity of the organically contaminated strata， which in turn can have an impact on the direct push drilling trajectory.
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WEI Tao, LIU Lisong, YAN Wenqin, WANG Le, JI Wenlong, SUN Pinghe
2024,51(3):37-44, DOI: 10.12143/j.ztgc.2024.03.005
Abstract:
Taking a shield tunneling project section in Xiaoshui as a case study， research was conducted to solve the key problem of the proportioning of grouting materials under karst geological conditions. A series of pre-tests were carried out in the pre-test period using raw materials such as clay， sand， gravel and cement， on the basis of which orthogonal tests on the factors of paste slurry proportioning were carried out by means of in situ soil extraction. The test results show that the dry clay and water-cement ratio are the factors that have the greatest influence on the compressive strength of the paste； The main influencing factor of the slump of the paste is the water-cement ratio， and the mixing amount of dry clay and sand contributes to the slump quite a lot； In terms of the compressive strength， the degree of contribution is in the order of the water-cement ratio>dry clay>sand. Considering the performance parameters and economy of paste slurry， it is recommended to choose No.6 （A2B1C3） paste slurry as the filling grouting material for this construction. The results of the study show that the preparation of paste slurry using clay and mechanism sand from the construction site can meet the requirements of the Design Institute for the performance index of karst filling materials.
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LI Jinyang, YIN Guolong, HUANG Hai, CHEN Long, TIAN You
2024,51(3):45-53, DOI: 10.12143/j.ztgc.2024.03.006
Abstract:
The rainfall conditions in the shallow hilly red layer area of Gongjue County in eastern Tibet are limited， and the occurrence and development of debris flows are mainly controlled by material source conditions and channel conditions， belonging to the “material source control type” of debris flows. Through geological investigation and statistical analysis， the conditions， mechanisms， and activity characteristics of debris flow formation were analyzed in detail. The following conclusion has been drawn： Gullies with a drainage area less than 1.0km2 and a longitudinal gradient of 100‰ to 300‰ are prone to debris flows； Due to the influence of structure， freeze-thaw weathering， and gypsum containing rocks， the sources of debris flows are relatively abundant， with slope erosion as the main type of source and a distribution characteristic of “multiple points and wide areas”. The supply form is characterized by “zero storage and whole extraction”； Controlled by the form of material supply， the formation of debris flows mainly includes three stages： slope erosion initiation， gully bed accumulation， and bottom erosion； Due to the influence of material sources， the fluid properties of debris flows in the area are mainly viscous transitional， and debris flows have the characteristics of multiple periods， medium to high frequencies， and smaller scale of single debris flows.
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2024,51(3):54-59, DOI: 10.12143/j.ztgc.2024.03.007
Abstract:
In order to comprehensively develop the geological disaster prevention and control technology system of “civil air defense+technical defense”， and build a geological disaster monitoring and early warning system based on universal monitoring instruments， this paper takes the Dayuanzi landslide in Baoshan City， Yunnan-Guizhou Plateau as an example， introduces the various links of the geological disaster landslide from scheme design to monitoring data screening and mode model design in detail， and the application of three parameters model in the monitoring and early warning system namely rainfall， displacement deformation and crack are expouneded. Through collecting key information of the geological disaster body， such as rainfall， displacement deformation and crack change， the monitoring and early warning model is optimizd， the threshold is adjusted， and the change information of the geological disaster body is captured in time. Moreover， the key link of building a universal monitoring and early warning system is completed relying on the self triggered early warning of the platform criterion model， thereby， the effect of universal monitoring and early warning is achieved and greatly improved the automation and intelligence of the geological disaster prevention system.
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CHEN Tao, ZHAO Huaxuan, LI Qiang, ZHAO Bin, CHEN Hao, JIANG Feng, YI Shiyou, GAO Feng
2024,51(3):60-68, DOI: 10.12143/j.ztgc.2024.03.008
Abstract:
The exposed karst areas has the characteristics of strong karst development and complex hydrogeological conditions， which leads to the concealed nature of the channels in underground river systems and the challenges for pollution prevention. Taking pollution prevention project in Pingqiao Underground River System as an example， the measure of “underground impermeable curtain + sewage pumping and drainage” was used in the main flow channels near the pollution source to realize “near source drainage truncation”.The construction faced difficulties such as blockages and low drilling efficiency due to complex karst fragmentation and excessive waste of materials due to long grout flow distances in strong karst segments. Effective technical measures such as suitable drilling techniques， pure pressure grouting， cement mortar grouting to fill dissolution voids， low-pressure and limitated volume grouting and accelerated slurry grouting were employed to ensure the quality of the project， which achieved the goal of contaminated groundwater treatment from the source. The technology of “near source drainage truncation” provides a replicable geoscientific management model for contaminated groundwater prevention in analogous hydrogeological conditions.
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WEN Guojun, HUANG Ziheng, WANG Yudan, SHI Yaocheng, JIANG Yuhao
2024,51(3):69-75, DOI: 10.12143/j.ztgc.2024.03.009
Abstract:
Laser drilling uses gas as circulating medium to clean holes， and the reasonable gas flow properties are the guarantee for hole cleaning efficiency. Gas nozzle is the direct factor affecting gas flow properties， and its unreasonable structural design seriously affects the efficiency of laser drilling. Aiming at the gas nozzle in the laser drilling experimental platform， the basic type of the nozzle is constructed， the nozzle structure size that affects the gas hole cleaning efficiency is analyzed， and the simulation scheme is formulated. Moreover， the gas flow field is simulated by Fluent， and the hole cleaning effect is analyzed. The nozzle structure and simulation results are analyzed by neural network， and the neural network model is trained to get and verify the best nozzle structure parameters for hole cleaning efficiency， which provides reference for the nozzle structure design.
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TANG Guowang, YANG Yong, DENG Qiang, ZHAO Zhongjun, ZHOU Kai, ZHANG Yu, YU Peizhi, WANG Guihe
2024,51(3):76-83, DOI: 10.12143/j.ztgc.2024.03.010
Abstract:
Drilling cuttings are a type of solid waste generated in drilling engineering， usually treated with cement for solidification. However， the production process of cement is accompanied by a large amount of carbon dioxide emissions， which not only increases greenhouse gas emissions but also has adverse effects on environmental protection. In response to the above situation， this article proposes a new method of microbial induced magnesium carbonate precipitation and solidification of drilling cuttings. The study on the mechanical properties of microbial induced magnesium carbonate precipitation solidified drilling cuttings shows that the strength of the solidified body decreases with the increase of water content and urea concentration， and increases with the increase of active magnesium oxide concentration and curing time. The minimum strength is 0.21MPa and the maximum strength is 3.5MPa， fully demonstrating the importance of selecting the most suitable ratio. The characterization results of FTIR， XRD， and SEM showed that the microbial induced precipitation products of magnesium carbonate were rose shaped magnesite （4MgCO3?Mg（OH）2?4H2O） and needle shaped magnesite （MgCO3?3H2O）； The product uses a dense carbonate network structure to bond loose particles into a structurally intact solidified body， thereby elucidating the mechanism of microbial induced magnesium carbonate precipitation and solidification of drilling cuttings.
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WANG Mengyuan, XUE Man, LIANG Mengjia, JIN Chunzheng, YANG Xianyu, CAI Jihua
2024,51(3):84-93, DOI: 10.12143/j.ztgc.2024.03.011
Abstract:
Natural materials have become an important direction for the research and development of environmentally friendly drilling fluid treatment agents due to their advantages of easy degradation， environmental friendliness， rich sources， and low prices. Based on natural pomelo peel， amide and sulfonic acid groups were introduced through chemical synthesis to form a modified pomelo peel fluid loss reducer that can meet the requirements of green， safe， and efficient drilling in high-temperature strata， and its temperature resistance， inhibition， and salt and calcium resistance performances were evaluated. Pomelo peels are rich in active ingredients such as plant phenols and polysaccharides. The modified pomelo peels have strong temperature resistance and a filter loss reduction rate exceeding 70% at 150℃. The rolling recovery experiment results show that at a dosage of 0.3%， its inhibitory effect is better than KCl. The anti-pollution experiment shows that the modified pomelo peel fluid loss additive has good salt and calcium resistance. At a dosage of 0.3%， it can keep the filter loss below 10 mL in fresh water base mud， salt water base mud， and saturated salt water base mud. When the CaCl2 content is 3%， the filter loss reduction rate reaches 82.22%. The modified pomelo peels have significant fluid loss reduction properties， providing new technical ideas for the development of environmentally friendly drilling fluid treatment agents.
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YAN Xiecai, ZHENG Jun, LUO Haohan, ZHANG Han, SUN Wan, DOU Bin, CHEN Yu
2024,51(3):94-103, DOI: 10.12143/j.ztgc.2024.03.012
Abstract:
Hot dry rock （HDR） is a clean and renewable energy resource developed mainly through enhanced geothermal systems （EGS）. In EGS engineering， geothermal drilling technology is required for the construction of both injection wells and production wells， and the formation fracture and wellbore collapse during high temperature and high pressure drilling are important problems in hot dry rock drilling construction. Under the action of temperature difference， the temperature stress is generated between mineral particles due to the difference of thermal expansion and cold shrinkage characteristics of mineral particles of rock， which results in thermal fracture of rock mass. In this paper， with the help of RFPA numerical simulation software， the fracture propagation of granite in wellbore under the action of cold shock during hot dry rock mining is studied. The results show that during the cold shock process of the wellbore model， as the increase of the cold shock time， the tensile stress on the rock surface first increases to a peak value and then decreases slowly. The fracture growth can be roughly divided into early， middle and late stages. In the early stage， an annular tensile stress zone appears around the wellbore and uniform micro-cracks begin to appear. In the middle stage， with the increase of time， the tensile stress zone gradually spreads to the periphery of the wellbore and the fracture spreads outward beyond the tensile stress zone. In the late stage， the tensile stress gradually decreases to less than the tensile strength of the model， and the fracture propagation slows down until it stops. The confining pressure， well diameter and temperature have a significant impact on the damage effect of the surrounding rock under cold shock. Among them， the temperature and well diameter promotes the growth of cold shock fracture while the confining pressure inhibits it.
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2024,51(3):104-110, DOI: 10.12143/j.ztgc.2024.03.013
Abstract:
In present， the measured location of the near-horizontal directional drlling trajectory is lag behind the bit， and the actural parameters of the delayed area can not be obtained in time， thus artificial prediction should be made for the next trajectory adjustion. In order to decreased the human facts and improve the accuracy of the prediction， a forecasting model is established based on BP neural network which is used for controlling underground directional drilling trajectory in tunnel. The model is a four-layer BP neural network， and it chooses 11 input parameters and 2 output parameters which are changed from 13 borehole space and trajectory controlling parameters from 12m before MWD including dip angles and azimuths etc. The parameters of the net forecasting model is obtained using 502 groups of training data from 6 boreholes in different mining areas. Then the forecasting results of the 12 groups of test data are compared with that of the artificial experience from 24 technicians. The results show that the mean absolute error of the downhole space parameters i.e. dip angle and azimuth are only 0.51° and 0.68° predicted inrespectively by the logsig activation function and the double-hidden-layer BP neural network which has the point structure of 9×6， and the prediction error obeys normal distribution. The accuracy prediction results derived from the BP neural network model is 35% lower than that from the technicians who work more than 5 years， and the effect from the field application is satisfied which meets the needs of drilling trajectory control. The research offers theoratical and practical base for the intelligent directional drilling work.
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TANG Fenglin, ZHAO Rongxin, Neskoromnyh V. V., LI Bo, ZHOU Xin, DUAN Longchen
2024,51(3):111-117, DOI: 10.12143/j.ztgc.2024.03.014
Abstract:
PDC bits are widely used in oil and gas drilling and geological exploration drilling. and good technical and economical results have been obtained. However，abnormal wear of the cutting element in drilling engineering affects the improving of technical and economic effectiveness of the advanced drilling method. Company Smith drill bit of Russia （Smith Bits） has developed a new cutting element， rotating around its inner shaft，inhibiting the wear of PDC cutting element. It is a new innovation and has practical significance. Prof Neskoromnyh V. V. et al have analyzed and researched on design and characteristic parameters of the bit with ONYX. Finished tests show， that the wear resistance of the ONYX is better than， that of the fixed PDC element. The result of drilling using such bit are better and the bits are being used actively in geological and prospecting organizations of Russia. It is worth for us to pay attention to.
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FENG Meigui, LIU Qidong, GUO Wei, ZHANG Peifeng, JIANG Rui, WENG Wei, XU Junjun, WU Shuo, JIN Bo
2024,51(3):118-124, DOI: 10.12143/j.ztgc.2024.03.015
Abstract:
In order to resolve the puzzle that the scaling on the inner wall of the drill pipe seriously restricts the safe， high-quality， and efficient implementation of wire-line core drilling， the comprehensive study was conducted on the scaling mechanism and influencing factors of diamond wire-line core drilling on the inner wall of the drill pipe. The results indicate that： When the structure of the drilling tool and the performance of the drilling fluid are constant， the solid content and particle size in the drilling fluid are the main factors affecting the scaling of the inner wall of the drill pipe. The particle size of rock cuttings produced by diamond core drilling ranges from 5 to 100μm， it is generally small and difficult to remove by the natural settlement. For the reason， the TGLW series small centrifuge is developed. Field tests have shown that the centrifuge can increase the peak value of solid particles in drilling fluid from 5~80μm to 3~10μm， the median particle size of the solid phase ranges from 11.189μm to 3.513μm， the solid phase clearance rate reaches over 90%， and the solid phase content of the drilling fluid is controlled below 0.5%， which not only maintains the performance of the drilling fluid but also prevents scaling on the inner wall of the wire-line drill rod.
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HE Huilan, WANG Jiuquan, LI Qiuyue, DING Xiangzhong, GU Xiaobin, LUO Wei, WU Shujun, GAO Ke, ZHAO Yan, LI Xu
2024,51(3):125-130, DOI: 10.12143/j.ztgc.2024.03.016
Abstract:
In order to improve the performance of the wire-line core drill pipe， the stress， structural characteristics and traditional treatment technology of the straight-connected wire-line core drill pipe were analyzed， and a zonal heat treatment process was proposed. Through the heat treatment of both ends， the heat treatment performance of the middle pipe body area and the thread area at both ends was different， and the comprehensive strength of both ends was improved while the stress state of the thread part was improved. It can make the drill pipe string have both high strength and flexibility， and greatly improve the mechanical properties and wear resistance of the drill pipe. The quenching and tempering hardness HRC33~38 can increase the strength by 37.7%， the hardness by 40% and the impact resistance by 46.7% under the condition that the elongation of the pipe body is basically the same as that of normalizing and tempering. When the quenching and tempering hardness is HRC38~42， the wear resistance of the material is increased by 9.1%. It is more suitable for full hydraulic drilling rig construction and deep hole drilling， and provides the optimal scheme for drilling rig and drill pipe matching.
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YU Haoyang, LI Yunzhou, HE Wantong
2024,51(3):131-135, DOI: 10.12143/j.ztgc.2024.03.017
Abstract:
Oil and gas well leakage is a common problem in drilling， usually sealed with cement. However， the heavy weight of ordinary cement can easily lead to failure in plugging. Meanwhile， low-density cement has been rapidly promoted in plugging. The compatibility between low-density cement and retarders is particularly important， which the performance of cement is effected seriously by retarders. In response to the above issues， a retarder for low-density cement. The infrared and thermogravimetric results indicated that the preparation of the retarder has achieved ideal results， with a temperature resistance of 450℃. The test results of the high-temperature and high-pressure thickener showed that a retarding time of 225 minutes was obtained for the low-density cement with 0.4% retarder under the conditions of 120℃ and 68MPa， which is a good retarding effect. By using a six speed viscometer， thickener， and unconfined compression tester， the effect of retarders on the conventional performance of low-density cement slurry was studied. The experimental results confirmed that different concentrations of retarders did not have a significant impact on the rheological properties and compressive strength of cement， and an increase in temperature would shorten the thickening time of cement slurry. The prepared retarder has been applied on site together with low-density cement， and the on-site results have shown that the retarder has excellent effects and meets the needs of on-site construction， which is worthy of further promotion.
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ZHANG Yongze, YU Jiancong, GAO Ning, SONG Xiaoguang, MEI Xuejia
2024,51(3):136-141, DOI: 10.12143/j.ztgc.2024.03.018
Abstract:
In order to study the shallow geothermal energy contained in the Ordovician limestone of Jingxing County， a thermal response test well in the valley is drilled， where the physical mechanics， thermal properties and geothermal field characteristics of the rock and soil mass are tested. As a result， the average geothermal temperature below 10m reached 16.77℃， and the heat transfer per unit length in summer and winter under the test conditions were 68.38W/m and 65.78W/m， respectively. Eight indicators such as the burial depth of the groundwater level and the velocity of the groundwater were selected to evaluate the suitability of ground source heat pump with buried pipe in Jingxing County， and the evaluation area was divided into more suitable area， suitable area and unsuitable area. Among them， the more suitable area is 244.12km2， accounting for 16.82% of the total area. On this basis， the resource potential evaluation was carried out on the more suitable area， and the resource potential and energy saving and emission reduction capacity were calculated. In order to better verify the development and utilization value of the shallow geothermal energy contained in the Ordovician limestone of Jingxing County， the relevant supporting application engineering and monitoring equipment were installed to monitor the energy consumption under different test conditions. Compared with the energy consumption of the ordinary household air conditioners， the annual operating cost of ground-source heat pump with buried pipe is about 55% of the air conditioning， which possess the development and utilization value.
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2024,51(3):142-149, DOI: 10.12143/j.ztgc.2024.03.019
Abstract:
In the process of drilling engineering construction， the mechanical failure will inevitably appear. The fault tree is one of the common methods to analyze the causes. But in the construction， due to the insufficient data or no attention to save these data， assigning value is difficult in the actual application and only qualitative analysis can be made. In view of the fuzziness and uncertainty when faults of the engineering construction machinery happened， the occurrence probability of the bottom event is described with fuzzy number， and a machinery fault tree analysis method for engineering construction based on triangular fuzzy number is proposed. This method uses the experience of experts， field technicians and operators to describe the probability interval of each bottom event. The median importance of the triangular fuzzy number is caculated and is used to sort the causes of the fault， which is served as the basis for formulating preventive measures. Finally， it is applied to the reason analysis of mix-material blocking pipe of long spiral drill， and makes targeted preventive measures for faults according to the fuzzy importance. The results show that the ranking of important influencing factors is consistent with the qualitative analysis and judgment of the field technicians and operators.
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XU Guohui, LIU Haisheng, MU Yuanhong, CHEN Long, YANG Haiyun
2024,51(3):150-156, DOI: 10.12143/j.ztgc.2024.03.020
Abstract:
In recent years， the main ore belt of Xitieshan has gradually entered deep exploration， mainly relying on tunnel drilling to determine the distribution and reserves of deep mineral deposits in the mine. During the implementation of tunnel drilling， challenges such as airport chamber support， drilling of fractured strata， core extraction of water sensitive strata wall protection， and treatment of water inrush strata are faced. If not handled properly， it can cause airport chambers to fall and collapse， and drilling accidents such as jamming， burying， and collapse may occur. In severe cases， drilling may be scrapped， which restricts the exploration process. In response to the technical difficulties in drilling complex formations mentioned above， research has been carried out on strengthening tunnel support， selecting reasonable drilling parameters， optimizing drilling structures， formulating complex formation flushing fluid formulas， and using rapid setting cement for sealing. This has ensured the construction safety of the tunnel airport， effectively solved the drilling difficulties in various complex formations in the area， reduced the incidence of accidents and drilling scrap rates， improved drilling efficiency and quality， and provided reference for subsequent drilling construction in similar formations.
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WANG Sheng, OU Xinggui, XIE Chengchao, YUAN Changjin, LI Zhijun, YUAN Jinke, TAN Huijing
2024,51(3):157-161, DOI: 10.12143/j.ztgc.2024.03.021
Abstract:
In recent years， as the most important means to access into the earth， drilling is facing the problems that the formation is becoming more and more complex， and the probability of drilling collapse， falling blocks， diameter reduction and over-diameter accidents is increasing， which seriously restricts the improvement of the quality and efficiency of drilling engineering. Wall protection and plugging material is an indispensable key engineering material for drilling engineering and the wall protection and plugging technology is an important technical link to ensure safe， fast and continuous drilling work and is the main content of drilling treatment in complex formations. From the perspective of science popularization， this paper introduces the basic concept and composition of wall blocking materials， the wall blocking effect of flushing fluid and cement-based materials and the further development space of wall blocking materials， so as to deepen the understanding of wall blocking materials and promote its R&D and application.
Volume 51,2024 Issue 3
综述
极端生态环境调查与保护修复专题
钻探理论与方法
钻探技术与装备
工程实践与应用
地学科普
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Drilling technology of Well Weire-1 for geothermal geological surveyy in Taikang Uplift, South North China Basin
GUO Chong, ZHU Huailiang, YANG Zhongyan, WANG Liyan, CAI Jinmeng, LI Wenlong, LIN Shengming, ZHANG Yuqi
Abstract:
Well Weire-1 is a geothermal exploration well deployed by Department of Land and Resources of Henan Province in western Taikang Uplift, South North China. The designed depth of the well is 3000m with the completion depth of 3306.80m, which is the deepest geothermal well in South North China area. The fault was well developed, and the reference materials from adjacent wells were lacking. The geothermal geology research is not thorough and the formation is extremely complex, which are prone to collapse and block falling during drilling. In view of the difficulties in drilling works, optimization of drilling equipment, drilling parameter selection, drilling fluid systems was conducted. These measures have ensured the smooth implementation of drilling operations and provides reference and guidance for the construction of deep geothermal drilling in this area. In addition, Thermal reservoir thickness, lithology, porosity and permeability, water yield, hot water temperature and other parameters of the deep thermal reservoir in the area were obtained by analyzing the physical core data, logging data and pumping test data, and the development characteristics and development potential of deep heat storage in this area are revealed, which provides a guiding direction for future geothermal exploration and development.
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Research and application of drilling plugging technology in Changqing area
Abstract:
In order to ensure well control safety, existing plugging materials have been added to the drilled areas of Changqing Oilfield for common leakage. However, there are technical difficulties such as water hole blockage of drilling tools, lack of signal from downhole instruments, and low success rate of one-time plugging. Therefore, wireless drilling instruments and downhole power tools have been optimized, and matching drilling plugging slurry has been developed to achieve rapid plugging of the leaking layer while meeting the requirements of permeability. This has formed the Changqing area drilling plugging technology, which has been applied in more than 100 wells on site, increasing the success rate of one-time plugging by 23.54%, significantly shortening the plugging time, improving plugging efficiency, and ensuring safe and rapid drilling and completion of wells.
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Study and Application of polymer drilling fluid system with easy degradation and strong anti-collapse inhibition for +304? hole in Huacaotan Kuangqu, Shandan County, Gansu Province
Abstract:
Hole +304 is a deep coal seam borehole drilled in Huacaotan Kuangqu.The buried depth of main coal seam generally exceeds 800m. The coal quality condition is mainly broken coal, poor cementation, high risk of fragmentation, loosening and collapse. During the use of conventional sodium clay polymer drilling fluid system, complex accidents occur continuously.In this paper, polymer drilling fluid system with easy degradation and strong inhibition is adopted. Water +4% sodium clay +0.05% soda ash +0.3% hydroxyethyl cellulose (HEC)+0.5% degradable polymer (JP)+1% fluid loss agent +1% anti-collapse agent +1% degradable plugging agent +0.5% lubricant + weighting agent (calcium carbonate), apparent viscosity 15~20 mPa·s, fluid loss <5ml, dynamic shear force 8~10 Pa, expansion rate less than 0.1%, using oxidation type gel breaker OPJ 1.0%, The degradation rate reaches 93.5%, the drilling footage is 1077.50m, and there is no collapse, diameter reduction and other complicated situations.
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Efficient Drilling Technology for Oil and Gas survey in Sanmenxia Basin
zhao hongbo, zhang long, shen lina, zhang jiaodong, liu xufeng, li dayong, hu hao, meng xianglong, zhu disi
Abstract:
【Background】The Paleogene sedimentary thickness in the Lingbao Sag of the Sanmenxia Basin is large and continuously distributed, with developed dark mudstone. Through the deployment of drilling projects, new discoveries of oil and gas in small and medium-sized basins can be assisted. However, the geological environment for drilling in this type of reservoir is complex, with frequent sand and mudstone interlayers, which can easily cause engineering difficulties such as bit mud entrapment, wellbore collapse, block falling, coexisting risks of leakage, and difficulty in drilling. 【Research method】 Through the optimization of drilling tool combination and wellbore structure, research on drilling fluid technology in different sections, development of PDC irregular tooth drill bits, and research on the drilling process of "low speed+medium drilling pressure+screw+high-efficiency PDC drill bits", 【Research results】effectively solved the problems of wellbore stability and drill bit selection. In the actual drilling of YXD 1 well, the average mechanical drilling speed of comprehensive drilling reached 5.67 m/h, which shortened the drilling cycle by 10 days compared to the design. 【Conclusions and suggestions】Innovations have formed a "new, superior, and fast" drilling and completion technology system for sand and mudstone interlayers in the Sanmenxia Basin, including a mud pack drilling fluid technology system, a long open hole wellbore protection drilling fluid technology system, an efficient PDC shaped tooth drill bit acceleration technology for sand and mudstone interlayers, and a "two low and one high" variable density cement slurry cementing technology that can be promoted. This can provide useful reference for drilling engineering design and construction in similar regions.
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Study on Cement Slurry System in Ultra-high temperature well
高元, LI Xiaojiang, LIU Rengguang
Abstract:
Aiming at the strength of set cement with sand degradation leads to the annular seal failure at 200℃, rich silica-aluminum material with hydration activity was developed, and when the adding amount for 30% to70% of cement ,the compresssive strength of cement are stable at 200℃×20.7MPa×30d. Based on the rich Silica-aluminum material as a high temperature stabilizer, selecting matching additives, the rich silica-aluminum ultra-high temperature cement slurry was developed, the API water loss is less than 50 mL at 100~200℃, the thickening time can be adjustable between 150~500min, the comprehensive performance is good. Compressive strength of set cement cured for 10d, 60d, 120d, 180d under 200℃×20.7MPa are all greater than 26MPa, and high temperature strength decline was not observed. The ultrasonic strength curve shows that the strength of set cement grows steady within 600h. The SEM and XRD shows that, the rich silica-aluminum material participate in the cement hydration reaction, and eliminate the calcium hydroxide, and generate aluminum-oxide tetrahedron and silica-oxide tetrahedron inter-bonding three-dimensional network structure with good high temperature performance, and together with tobermolite calcium silicate bauxite to maintain the stability of the high temperature strength of cement stone. The cement slurry system has been applied in hot dry rock cementing for 1 well, and the cementing quality is good. As so far, the cement ring has been well sealed for 1000 days.
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Numerical Simulation Analysis and Optimization of Process Parameters in the Cementing Process of Gas Hydrate-bearing Sediments in Deep Water Oil and Gas Wells
WANG Xiaoyu, ZHENG Mingming, WU Shuang, YAN Shichun, MA Ting, TANG Chengxiang
Abstract:
The South China Sea has been confirmed to be rich in oil and gas resources as well as natural gas hydrate resources. However, hydrate-bearing formations are often encountered during the drilling of oil and gas wells. Cementing is a critical step in oil and gas development. In deepwater drilling, the heat released during cement hydration can potentially induce hydrate decomposition, compromising formation stability and even affecting cementing quality. This study utilized numerical simulation methods, focusing on the hydrate-bearing formation at the SH7 site in the Shenhu area of the South China Sea GMGS-1 project. A numerical model for cementing was established to analyze the issues caused by cement slurry invasion into hydrate-bearing formations and the impact of cementing process parameters. The study found that an increase in cement hydration heat release rate significantly advanced the onset of gas and water influx, as well as increased its volume. The cementing pressure differential had a minor impact on the influx phenomenon, but it suppressed the influx when exceeding a certain threshold. Prolonging the pressure maintenance period significantly delayed the initiation of influx and reduced its volume. Therefore, it is recommended in practical engineering to use low-heat cement, extend the pressure maintenance period, and avoid excessively high cementing pressure differentials in the early stages to minimize hydrate decomposition and mitigate the occurrence of influx. This research provides a theoretical foundation for the cementing of hydrate-bearing formations, which is of great significance for enhancing the safety and efficiency of cementing operations.
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Construction technology of super-large diameter feed hole in coal mine
shitianfeng, wangkai, luoqingyin, zhaoyuanqiang
Abstract:
A large amount of coal gangue dumped on the ground of coal mining enterprises not only occupies land resources, pollutes the surrounding environment, increases the cost of enterprises, and even has the possibility of explosion, which needs to be solved as soon as possible. By drilling a super-large bore hole from near the ground coal gangue bin to the underground roadway, using the pre-construction of small bore pilot holes, opening five-stage reaming in one place and four-stage reaming in the second place, and drilling with the positive circulation of mud and the reverse circulation of gas lift by the cone bit, the coal gangue solid waste is drilled into a coal mine with a super-large diameter feeding hole to transport the solid waste to the underground goaf. It can not only solve the environmental pollution caused by the dumping of coal gangue on the ground, but also effectively control the movement and deformation of the surface, and realize the green and sustainable development of coal mines. Through the construction practice of large diameter feeding hole in Beixulou Coal mine of Tenbei Mining area, the construction technology of drilling for large diameter feeding hole is explored, and its mature construction scheme has certain guiding significance for the large diameter drilling project.
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Finite element numerical simulation analysis of packer-type expansion pipe
Liyunpeng, Yinfei, sunxiao, Fengjianyue, Liuyi, Chenzhiang, Zhengyunfei
Abstract:
The packer expansion tube technology has been developed for the hydrogeological exploration of wall protection and the repair of damaged well pipes. It has the characteristics of low cost and simple process. In order to make the packer meet the requirements of the expansion pipe, the expansion mechanism of the packer is improved. The packer is used to test the pipes with different properties. According to the test results, 316L stainless steel is selected as the expansion pipe. In order to study the relationship between the expansion pressure and the change of the length and thickness of the expansion tube during the two expansions of the packer-type expansion tube, the expansion process of the expansion tube with Φ219 mm and wall thickness of 4 mm was numerically simulated by Abaqus software to obtain the change of stress and strain during the expansion process, and field tests were conducted on the expansion tube with the same specifications. Then comparing the simulation results with the test results, it is concluded that the simulation results are basically the same as the actual demonstration results, indicating that the numerical simulation results can be used as a reference for the actual construction.
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Experimental study on the thermal characteristics of dry drilling of diamond coring bits
SHEN Lina, LI Chun, ZHAO Yi, LIU Hailong, WU Haixia, ZHANG Jianyuan
Abstract:
Dry drilling has little impact on the environment. In the absence of cooling medium, it can effectively solve the problem of borehole coring when drilling some water or drilling fluid reacts or produces new pollution, so this method is one of the important means of exoplanets sampling. However, exoplanets object drill bits were mostly alloy drill bits, which had certain limitations for drilling into hard rock formations. Diamond drilling is a relatively advanced rotary drilling technology, which is widely used in oil and gas exploration and geological exploration, and is a powerful tool for drilling hard rock formations. In this paper, the dry drilling tests of diamond drill bits were carried out for hard granite, and the influences of drilling parameters and bit types on the thermal characteristics during the drilling process is discussed. The results show that: (1) The heating rate of PDC drill bits is lower than that of conventional diamond coring bits, which is about 1/2 of that of impregnated diamond bits; (2) PDC coring bits can be a way for the dry drilling of granite under suitable process parameters; (3) The rotary speed has a great influence on the temperature rise of diamond bits in dry drilling, and it shows a nonlinear growth trend; (4)The cooling curves of drill bits in air show an exponential downward trend. During the cooling from 300°C to 100°C, the cooling rate ≥ 60°C/min. The research results can provide a basis for the scientific design and rational use of dry drilling bits.
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Research on the criterion of hole accident about Core drilling based on Expert Knowledge and Parameter Thresholds
YANG Ke, PU Chun, LIAO Linxiang, CAO Zaokai
Abstract:
In the strategic action of ore prospecting breakthrough, the drilling depth is constantly increasing, and intelligent working condition recognition has become a necessary measure for safe, efficient and low-cost drilling. Its steps include signal acquisition, feature extraction, state recognition and diagnosis decision, among which the establishment of accurate and reliable in-hole accident discrimination criterion is the difficulty and core of state recognition and diagnosis decision. Firstly, based on the theoretical knowledge and engineering practice experience of in-hole accidents, this paper divides the six types of accidents in drilling holes into buried drilling, stuck drilling, burned drilling, broken drilling, hole leakage and hole overflow, and summarizes their occurrence symptoms. The characteristics and change trend expression of real-time drilling signal parameters are analyzed in detail. On this basis, the relative mean, standard deviation, mean slope, standard deviation slope and their thresholds of six characteristic parameters, including pump pressure, drilling speed, torque, rotation speed, overhead weight and outlet flow, are proposed to characterize the change of each parameter. Finally, the accident discrimination criterion is established in the form of matrix. The discrimination criterion has strong theoretical and practical basis, and can divide the detailed drilling accident categories in actual use, which can provide a discrimination basis for subsequent software development.
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The Correction and Anti-skew Ability of Single Bend Bistable Screw Drill Assembly
LIU Heng, TONG Zhaojun, QIAO Hongguo, LUAN Baokun, JIANG Shan, ZHANG Hai, HAN Hailiang
Abstract:
With the deepening of exploration and development of deep geological resources in China, deep mineral deposits have become the focus of geological prospecting work. In the process of deep prospecting and drilling, the problem of maintaining the straightness of the vertical well section in the high steep structure has been a major problem for drilling technicians, which seriously affects the exploration efficiency of deep mineral deposits. In the inclined section, the single bend bistable screw drill is the most commonly used anti-deviation and correction drill assembly. In this paper, a mechanical model of BHA is established based on the crossbar bending beam method and the principle of equilibrium trend. The influence law of each factor on the deviation correction ability is analyzed through the model, and the main control factor is determined by the orthogonal test design method. Finally, based on the theory of multi-objective optimization, a multi-objective optimization method for control parameters of fast drilling is established to obtain the optimal parameter combination. Based on the above research, a set of anti-skew and straightening optimization design method is developed to improve the drilling efficiency of the vertical well section of the high steep structure, and promote the efficient and low-cost drilling and development of deep mineral deposits.
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Experimental analysis of respiratory effect characteristics of deep fractured formation
黄洪林, Luo Ming, Li Wentuo, Wu Yanhui, Ma Chuanhua, Li Jun, Gao Reyu
Abstract:
When drilling deep fractured formation, the formation breathing effect caused by wellbore pressure fluctuation is easy to be misjudged as overflow and unnecessary killing measures are taken, which seriously affects the drilling safety. Therefore, an experimental equipment was developed to simulate the breathing effect of fractured formation. A series of experiments were carried out to analyze the effects of drilling fluid circulation pressure, fracture opening pressure and rock type on the characteristics of drilling fluid leakage and flowback. The results show that the fractured breathing effect is a reversible leakage, and the whole process of its occurrence is leakage - “quasi-steady” - flowback. With the increase of circulating pressure of drilling fluid, the maximum leakage and return amount of drilling fluid increased. With the increase of fracture opening pressure, the maximum leakage amount of drilling fluid increases, but the return amount decreases. Compared with sandstone and limestone, granite with extremely low porosity and low permeability has larger leakage and smaller return amount. The research results provide a theoretical basis for analyzing the characteristics of fractured breathing effect of deep fractured formation and adopting correct measures to distinguish other operating conditions.
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Research on dual liquid plugging method based on thixotropic slurry
龚浩宇, Ren peigang, Zhang furong, Ma di, Xie bingxi, Fan haijiao
Abstract:
Aiming at serious leakage problems such as crack type and karst cave type, a dual liquid method is proposed for plugging. Specifically, it is a new type of plugging technology that injects two or more fluids with different properties into the wellbore at the same time, and uses the thixotropy generated by the mixed fluid to seal the lost circulation layer. In order to study the plugging performance of mixed fluid and obtain the best plugging formula, organic gel solution is used to prepare cement slurry indoors, and mixed with Bantu slurry in different proportions. The thixotropy of mixed slurry is measured by hysteresis loop method to evaluate its plugging performance. The results show that when the dosage of organic gel is 0.08% bwoc, the cement slurry prepared by organic gel solution and 0.25% Bantu slurry are mixed at a ratio of 10:1.8, the slurry has the best plugging performance, and the compressive strength after curing can meet the requirements of on-site construction.Field application shows that the combination of cement slurry prepared with organic gel solution and bentonite slurry has good plugging effect.
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Cementing quality evaluation method research by image recognition technology
ZOU Zhuofeng, ZHANG Baoquan, LI Hui, Wang Jianhua, WANG Haitao, GUAN Zhen
Abstract:
There are many researches on cementing implementation methods and engineering detection methods of cementing quality, but the analysis of picture results on cementing quality is relatively rare. In this paper, a text coordinate position reference algorithm for focusing image analysis range and an image analysis algorithm based on histogram similarity and gradient distance are proposed to evaluate cement quality using evaluation image. A combination of image analysis algorithm and business mechanism is used to extract quantitative data from the evaluation image to evaluate cementing quality. Through comparison of model experiments, the proposed image analysis algorithm can accurately identify the cement quality information in the picture, and the error rate between the analytic results and the actual results is less than 10%. The method proposed in this paper can effectively solve the shortcomings of low efficiency and large error of manual analysis, and provides a practical solution to the situation that electronic data of cementing quality is missing and only the cementing quality evaluation image is kept. The proposed algorithm has strong exploratory significance for deep mining of cementing quality pictures.
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Analysis of casing friction in horizontal well
Chen Zhiming, Zhao Hu, Wen Dayang, Feng Qinghao, Liu Tianle
Abstract:
The prediction of the hook load during casing insertion is one of the key factors for success. Due to its special wellbore trajectory, the frictional resistance during casing insertion in horizontal wells is higher than that in conventional wells. Therefore, accurately predicting the frictional resistance of casing insertion plays an important guiding role in the design and construction of horizontal well cementing. At present, many friction prediction analysis models have been developed in the industry, and relevant theoretical research and case analysis have been carried out. The commonly used analysis methods include Soft-String Model, Stiff-String Model and finite element method. Subsequent scholars used various theoretical methods to consider the friction analysis model of casing under various stress conditions on the basis of the three methods, but there is currently no relevant research that summarizes and analyzes the advantages and disadvantages of existing model algorithms, making it impossible to conduct model optimization in specific applications. Therefore, according to different basic theories, this paper classifieds and analyzes the current casing friction models, and discusses the existing technical bottlenecks in casing friction research and prediction as well as the next development direction, in order to provide guidance and help for the in-depth integration development of casing friction analysis in the future.
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Long open hole and long-immersion formation drilling technology
Zhu Di-si, Meng Xiang-Long, Wang Sheng-jian, Wang Xiao-ming, Chen Zhao-ming, Chi Huan-peng, Zhao Hong-bo, Gao Yong-jin, Li Da-yong, Yue Wei-min
Abstract:
Well Xinsudi-2 is an oil and gas geological survey well deployed in the Xinjiang Tarim Basin. The well was drilled to 2468.50m with an open hole section of 2009.24m. After geological assessment, it was designed to be Deepen drilling to 3168m. This article takes the 500-600m well section as an example to analyze the wellbore stability. The wellbore is soaked in drilling fluid for a long time, which causes the water content of the wellbore to increase. The cohesion and internal friction angle of the mudstone and other strength indicators decrease, resulting in the wellbore not having Pressure-bearing capacity, slight disturbance will cause the well wall to become unstable. The project team adopted a new anti-pollution polymer anti-collapse drilling fluid system, a drilling tool assembly with a drill-while-drilling jar to relieve stuck conditions under complex well conditions, and the target layer was drilled using low drilling pressure\low rotational speed\low-displacement parameter combination drilling and other technical methods has solved a series of complex situations caused by long open-hole sections and long time soaked formations, ensured the smooth completion of the project and achieved the geological purpose, and accumulated the experience and technology of drilling long open hole and long-immersion formations.
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Development and Application of Impregnated Diamond Bit for Horizontal Directional Drilling in Hard Formation
Abstract:
Aiming at the low efficiency of horizontal directional drilling in hard formation, the self-sharpness of the bit was improved by the hard brittleness of FeCoCu pre-alloy matrix and the hard silicon carbide particle to weaken the matrix. The layered structure design is used to alternate the high and low wear resistance layers along the radial direction of the bit. The thickness of low wear resistance and high wear resistance were designed to be 1.0 ~1.5 mm and 2.5 ~3.5 mm respectively, to realize simultaneous wear of high wear resistance layers and low wear resistance layers and improve drilling efficiency. The bits have been successfully applied to horizontal directional drilling in hard potassium feldspar granite formation, using the combination of FeCoCu pre-alloy matrix and stratified matrix structure, with the average ROP of 0.8 ~1.5 m/h and the drilling life of 30 ~40 m. Compared with the ordinary concentric sharp tooth bit, the ROP has been increased by about double, and the drilling life has been increased by more than 30%.
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Research and Application of Leakage Prevention and Plugging Technology for Drilling Fluids in Changning Shale Gas Block
JIAO XIAOGUANG, WANG DAN, LI XIANFENG, NIU ZUOJUN, PENG YUNTAO
Abstract:
Changning shale gas block is located between the low steep tectonic belt of Sichuan South and Loushan fold belt in Sichuan Basin, affected by the surface karst landform and accumulation body, the surface drilling leakage and collapse are serious, and the environmental protection pressure is high; the middle and lower strata are affected by the underground faults, fracture development, low pressure-bearing capacity and other complex geological conditions, the wells leak seriously, and the window of safe density of the drilling fluids is narrow, the leakage of spraying and collapsing exist at the same time. There are multiple leakage layers from top to bottom of the well, and it is difficult to plug the leakage on site with low success rate. By analysing the actual drilling data of the neighbouring wells and summarizing the construction experience, the team selected a bridge plugging synergist and a bag-type plugging agent to enhance the effect of bridge plugging, and at the same time, optimized the on-site plugging procedures and processes, forming a technical plan for leakage prevention and plugging in Changning shale gas block, which was popularized and applied in the Ning 209 block. The success rate of one-time plugging of water-based drilling fluid leakage in the upper Maokou-Qixia Formation was increased by 42%, and the oil-based drilling fluid leakage in the target layer Longmaxi-Wufeng Formation decreased by 70%.
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SStudy On the Design and Hydraulic Characteristics of the Submarine Mud Lift Pump
Qin Rulei, Gao Jieyun, Chen Haowen, He Guolei, Xu Benchong, Su Xianghui, Yin Guoyue
Abstract:
The mud lift pump, as the core functional unit of riserless mud recovery drilling, drives the cutting-bearing mud stored in the suction module to flow back to the drilling platform along the upward return pipeline. This paper takes centrifugal pumps as the research object, constructs a computational model of the pump through CFD-EDM, conducts full-scale flow field simulation, and studies the impeller design, flow field and particle transport distribution, and hydraulic performance tests of the sample pump. The research results show that the pump has good working characteristic indicators, and its hydraulic performance meets the design requirements, the pump can be applied to deep-sea riserless drilling operations. And it also shows that the design method and experimental process of the pump are reasonable and feasible.
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Research and application of drilling and flushing fluid technology for thick water sensitive formations in the Miaoershan area of Guangxi
Abstract:
The potential for uranium exploration in the Miaoershan area of Guangxi is enormous, but part of the local strataformations are complex, with large thickness of water- sensitive and broken formations. During drilling construction, difficulties such as hole wall collapse orand excessively large boresuper diameter occur frequently, leading to frequent accidents in the hole, which and seriously affecting the construction progress. Therefore, mineral composition and microscopic characteristics of water sensitive cores in the area were analyzed. The lithology analysis results show that there are a large number amount of clay minerals such as Montmorillonitemontmorillonite, Kaolinitekaolinite, hydromica, etc. in the water water-sensitive formationsstratum, and the microcracks are developed with serious hydration expansion. To solve above problems, A new type materialsof with film forming and wall protecting functions on flushing fluid system waswere optimized through indoor evaluation experiments, and a flushing drilling fluid system with good wall protection performance was further developed, which consists of 5% film-forming agent A, 3% film-forming agent B, 1.5% modified asphalt, 1% plugging agent while drilling, 1%sealing agent, 0.6% viscosifier, 0.2% coating agent. The results indicate that the film forming solution The API filtration loss of this drilling fluid is 5-8mL, and the relative expansion reduction rate reaches over 87%. This drilling fluid can effectively inhibit hydration expansion of the water-sensitive formations,hydration and the wall protection effect is significant. This technology has been successfully applied in three boreholes in the Miaoershan area, smoothly successfully drilling through water water-sensitive formations without any problems such as core dispersion or hole wall collapse. Good application results have been achieved, and a film forming and wall protection flushing drilling fluid technology has been preliminarily formed for water water-sensitive formations in this area.
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Engineering survey and drilling automatic supervision system based on laser ranging technology
Abstract:
With the development of modern engineering technology, engineering exploration drilling play a crucial role in civil engineering, mining and other fields. However, the traditional engineering exploration drilling operation has some problems, such as low efficiency, many safety risks and inaccurate data collection, which need to be solved urgently. In order to improve the efficiency and safety of engineering exploration drilling operation, this paper aims to discuss the design and application of the automatic monitoring system of engineering exploration drilling operation process based on laser ranging technology, in order to provide useful reference for the modernization and intelligent development of engineering exploration exploration industry.
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Study on Simulation Characteristics of Phase Change Materials for High Temperature Resistant Vacuum Flask
liu dan, chen jian yao, hou yue, he nan, LIU Jingtao, zhou shao wu
Abstract:
With the continuous improvement and expansion of the application scope of active magnetic measurement technology represented by SmartMag Drilling Target-Hitting Guide System, it will be more applied in high-temperature underground environments such as geothermal well development and deep-sea mineral resource exploration in the future. High temperature often becomes a bottleneck problem that restricts the normal operation of instruments.In order to further improve the temperature resistance performance of the SmartMag system, this article adopts passive thermal management method and uses finite element method to simulate the phase change heat storage characteristics of the vacuum flask. It explores the optimal coupling length of the heat absorbing body and compares the phase change materials with the best temperature control ability horizontally. It analyzes the changes in axial temperature and phase state of the heat absorbing body inside the vacuum flask over time.The results show that the optimal coupling lengths are 400mm for the upper absorber and 250mm for the lower absorber. After operating the insulation cylinder at 150 ℃ for 6 hours, the utilization rate of phase change latent heat of the upper absorber is 96.7%, and the utilization rate of phase change latent heat of the lower absorber is 70.5%. The minimum temperature of the circuit board is 63.48 ℃, and the temperature control effect of low melting paraffin is the best.
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Analysis of working dynamics of ball valve with pressure core sampler
Han Zelong, Li Xiaoyang, Zhao Ming, Song Gang, Zhang Xin, Jiang Yafeng, Tian Yingying
Abstract:
The pressure holding coring technology can keep the extracted core under in-situ condition, minimize the loss of important data in the core, and then accurately obtain important formation parameters which can calculate the reserves of mineral resources. In this paper, the ball valve mechanism of pressure core sampler is studied by numerical simulation, and its dynamic characteristics are explored to optimize the ball valve mechanism. The results show that with the increasing of thrust force on the ball valve, the shorter the closing time of ball valve, but the vibration generated increases, which is easy to cause seal failure. Thus, the small thrust force is selected to help improve the sealing reliability. With the decreasing of friction coefficient, the ball valve closing time also decreases. However, the vibration generated increases, making the leakage risk of ball valve much bigger. When the ball valve is closed, the pressure simulation of 30MPa is conducted. The maximum contact stress is 133.67MPa and the maximum strain is 0.0328, which are both within the allowable range of ball valve.This study are meaningful to guide the optimal design of ball valve mechanism and improve its working reliability.
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