Online number:
Total visits:

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Lost Circulation Early Warning Technology Integrated with Geology and Engineering for Fractured Reservoirs in Bohai Oilfield
ZHANG Xiaocheng, HUO Hongbo, LIN Jiayu, LIU Hailong, LI Jin
 doi: 10.11911/syztjs.2022025
[Abstract](22) [FullText HTML](6) [PDF 3530KB](0)
In order to solve the problems of downhole leakage caused by faults and fractures in the drilling process of fractured reservoirs in Bohai Oilfield, a geology-engineering integrated lost circulation early warning technology was proposed. Starting from the track design to avoid drilling, on the basis of the large and mesoscale faults in post-stack earthquakes before drilling, through special processing such as filtering and fault enhancement, attribute optimization and multi-attribute fusion are carried out to finely describe small and medium-scale fractures and establish multi-scale fractures. The three-dimensional spatial distribution model of fractures is used to prompt pre-drilling risks and guide drilling operations to take corresponding leak prevention and plugging measures; During the drilling process, the lost circulation risk tracking while drilling is carried out, the results of the lost circulation risk prediction are adjusted and fed back in real time, and the wellbore trajectory is optimized in a timely manner. The dynamic leakage layer avoidance technology while drilling has been formed, which fully guarantees the safety of drilling operations and reduces operating costs. The above-mentioned series of technologies such as pre-drilling risk prediction, lost circulation tracking during drilling, and real-time optimization of the trajectory while drilling have successfully achieved on-site drilling to avoid the fault leakage section in Lvda X Oilfield. The geology-engineering integrated lost circulation early warning technology can effectively avoid drilling risks and ensure the safety of fractured reservoirs. This technology provides technical support for Bohai Oilfield's seven-year action plan to increase reserves and increase production.
Research on Optimized and Fast Drilling Technology for Luzhou Deep Shale Gas Horizontal Well
LI Tao, YANG Zhe, XU Weiqiang, YANG Qiang, YANG Zhaoliang
 doi: 10.11911/syztjs.2022036
[Abstract](35) [FullText HTML](3) [PDF 1621KB](7)
The Longmaxi Formation shale of Luzhou deep shale gas reservoir is deeply buried and has high temperature. During the drilling process, it is faced with technical problems such as frequent lost circulation, low ROP in difficult formations, high failure rate of steering instruments due to high temperature and long drilling cycle. For this reason, on the basis of analyzing the actual formation conditions and drilling technical difficulties in the early stage, the optimization of well structure and well trajectory, the optimization of high-efficiency bits, the optimization of plugging technical measures, the surface cooling of oil-based drilling fluid, and the underbalanced drilling technology have been studied, forming the optimal and fast drilling technology for Luzhou deep shale gas horizontal well. This technology has been applied to 34 shale gas horizontal wells in Luzhou Block. The average drilling depth of the test well is 5 760 m, the length of the horizontal section is 1 890 m, and the average ROP is increased from 5.61 m/h to 7.03 m/h, creating a record of completing drilling in one trip in the deflecting section + horizontal section, and the footage of a single trip is 2 330 m. The optimized and fast drilling technology for Luzhou deep shale gas horizontal wells has supported the safe drilling of deep shale gas in Luzhou Block, and has certain technical reference value for the drilling of deep shale gas horizontal wells in other regions.
Liner Cementing Techniques for Complicated Deep Wells in Sun Basin, North Yellow Sea
HU Jinjun, HAN Guanghai, ZHANG Haifeng, SHI Weiji
 doi: 10.11911/syztjs.2022098
[Abstract](16) [FullText HTML](4) [PDF 1855KB](3)
The complex geology of Sun Basin in North Yellow Sea including loss and falling cuttings which caused poor cementing quality in liner. Improve wellbore condition before cement job, choose slips-embedded liner hanger with packer to expand annular flow area, develop matrix flow restriction cement slurry mixing with fiber to reduce risk of leakage. Finally, a set of anti-blocking and anti-leakage narrow annular liner cementing technology suitable for complicated deep wells of Sun Basin in North Yellow Sea has been formed. That have been applied in 4 wells, no loss and annular blocking took place and all the cementing reached effective sealing. The applying result shows that this technology can effectively improve cementing quality and benefits further exploration.
Cause Analysis and Technical Countermeasures for Sustained Casing Pressure in Large-size Casing in the Kuqa Piedmont
AO Kangwei, TU Siqi, Yang Kunpeng, XIA Yuanbo, ZENG Jianguo
 doi: 10.11911/syztjs.2022042
[Abstract](26) [FullText HTML](2) [PDF 2038KB](5)
With the increasing depth of oil and gas exploration and development in Kuqa piedmont, the cementing environment of large-size casing becomes increasingly severe, the problem of sustained casing pressure occurs frequently and has become the main contradiction of the problem of sustained casing pressure which in the Kuqa piedmont. Aiming at this problem, the reasons of sustained casing pressure in large-size casing in the Kuqa piedmont were analyzed from the perspectives of mechanics and displacement by using field data analysis and laboratory test evaluation methods. It is found that the cement stone has no fatigue failure and the cement sheath maintained a good sealing integrity in the alternating load test under the simulated conditions. Poor wellbore condition, limited means of handling complex situations with staged cementing method, poor displacement and pressure stabilization measures lead to serious channeling in large-size casing cementing, and the high-pressure fluids is not stabilized. The poor quality of primary cementing is the root cause of sustained casing pressure in large-size casing in the Kuqa piedmont. By strengthening the wellbore preparation, improving the centering degree of the pipe string, increasing slurry friction difference and wall shear stress, strictly requiring the thickening time and transient time of the cement slurry, and refining the pressure-holding procedure, the large-size casing cementing technology with rapid sealing and full pressure stability was formed. This technology has been successfully applied for 6 wells in Kuqa piedmont, and the cementing quality is good, which effectively solving the problem of sustained casing pressure in large-size casing in the Kuqa piedmont.
Analysis of Transmission Characteristics of Hydraulic Controlling Signal in Intelligent Well
YU Guimin, XU Liangbin, XIE Renjun, SHENG Leixiang, HE Dongsheng
 doi: 10.11911/syztjs.2022099
[Abstract](13) [FullText HTML](8) [PDF 3366KB](6)
The intelligent well system of hydraulic controlling is used widely because of its good reliability, and its control method is to transmit the hydraulic control signal and hydraulic power downhole through thousands meters of hydraulic control pipe line, to realize the purposed downhole stratum selection and the flow control of purposed stratum. When transmitting the hydraulic control signal downhole, the signal will attenuate due to the friction and elasticity of the transmission pipeline, and the signal transmitted downhole may no longer have the same shape of the ground signal, so it is difficult to be identified by the downhole equipment. In order to control the downhole flow controller reliably, the transmission characteristics of the signal should be studied so as to correctly transmit the desired hydraulic signal to the downhole controller. Firstly, the transmission speed of the hydraulic control signal is discussed; then the influence of temperature changing on the viscosity of transmission medium is discussed too. The pressure and time relationship along the tubing during wellhead pressure propagates is analyzed, then the control signals shape changing transmitted downhole from the ground is discussed, and the propagation characteristics of control signal and power signal propagated downhole synchronously are studied too. Factors such as downhole pressure changes with resistance and without resistance of downhole sliding sleeve opening; different controlling pipe diameters, different pipe line raising pressure methods, different hydraulic oil viscosity grades, land wells and deep water wells are taken into accounted. It is concluded that the air content in hydraulic oil has a great impact on transmitted speed of downhole pressure wave, and it will takes about 25 minutes for wellhead pressured signals to reach 3 000 m downhole stratum, and the wave pattern becomes dull and its rising and falling edges of the waveform becomes flatten.
Calculation method of integrated pressure and formation parameters in gas injection process of underground gas storage
LIU Hui, DING Xinlu, ZHANG Shijie, FANG Yungui, HAO Xiaobo, XU Weihong, ZHENG Weige
 doi: 10.11911/syztjs.2022047
[Abstract](14) [FullText HTML](11) [PDF 1802KB](2)
In order to fully grasp the dynamic change process of pressure in gas injection process of underground gas storage(hereinafter referred as UGS) and solve the problem of difficult determination of formation parameters caused by continuous gas injection, on the basis of the static and dynamic data, researched and analysed the gas injection process of pressure change rule and influence factors, comprehensive reservoir, bottom hole and well head pressure calculation method, and integrated pressure calculation, based on an improved particle swarm optimization algorithm and intelligent fitting of measured wellhead pressure, a calculation method of integrated pressure and formation parameters in gas injection process of UGS was established. Through 3 pressure calculation methods, the improved particle swarm optimization algorithm was used to adjust and optimize the parameters, so that the calculated wellhead pressure and measured wellhead pressure can reach the best fit, and getting reservoir pressure, bottom hole pressure, and then the formation parameters such as average permeability, radius of investigation were obtained. The results are applied to 3 example wells of Hutubi UGS, and the correlation of pressure calculation results are 0.9889, 0.9893 and 0.9784, respectively, indicating that the calculated results are reliable. The later pressure is predicted based on the determined formation parameters. The research results provide a theoretical method for the calculation and prediction of pressure and the acquisition of formation parameters in the process of UGS, which is helpful to guide the safe operation of UGS.
Establishment of Pressure Profile and Optimization of Well Structure in the Southern Shunbei No. 5 Fault Zone
LI Shuanggui, LUO Jiang, YU Yang, TANG Ming, YI Hao, ZENG Dezhi
 doi: 10.11911/syztjs.2022037
[Abstract](38) [FullText HTML](20) [PDF 2241KB](2)
The southern part of the Shunbei No. 5 fault zone is affected by the fault tectonic movement, and problems such as malignant leakage and low drilling efficiency are common during the drilling process. Therefore, based on the imaging logging data and drilling data of adjacent wells, a new leakage pressure calculation model was established, and the prediction results of four pressure profiles in the southern formation of No. 5 fault zone were obtained; according to the four pressure profile and the analysis results of geological difficulties, the undeveloped area of the intrusion is optimized from the original five spuds to four spuds, and the borehole size is reduced to shorten the drilling cycle; a conventional four-spud casing program suitable for strong formation pressure-bearing capacity and a conventional five-spud specially sealed casing program to reduce the size of the wellbore are designed for the development area of the intrusive body, which improves the wellbore stability. The field test shows that the prediction results of the established leakage pressure calculation model have high accuracy. By using the optimized conventional five spud special sealing well structure, the average drilling cycle is shortened by 44 to 55 days, and the cementing quality qualification rate is increased by 37%. The research shows that the optimized well bore structure in Shunbei No. 5 fault zone can effectively improve the drilling efficiency, and provide a technical reference for the design of ultra-deep well structure in complex formation.
Research of Guar Gum Drilling Fluid in CBM Horizontal Wells in Qinnan Area
GENG Xueli, ZHENG Xiaobin, SU Yanhui, JING Qian, SHI Bin, LI Jian
 doi: 10.11911/syztjs.2022038
[Abstract](20) [FullText HTML](2) [PDF 1709KB](2)
Based on the analysis of reservoir characteristics and drilling technical difficulties, guar gum drilling fluid and bio enzyme gel breaking fluid were developed to solve the problems of wellbore collapse and reservoir damage when clean brine and conventional polymer drilling fluid were used in horizontal well drilling of No. 15 coal seam in Qinnan area. Guar gum drilling fluid is formed by optimizing the dosage of guar gum and evaluating the salt resistance, and matching other treatment agents; Through the optimization of biological enzyme type and dosage, and the study of drainage performance, a biological enzyme gel breaking solution was formed. The indoor test shows that guar gum drilling fluid has good rheological and salt resistance properties, can greatly improve the compressive strength of coal and rock, is easy to break at low temperature, the residue after breaking is less than 300 mg / L, and the permeability recovery rate of coal and rock is more than 85%. After the application of guar gum drilling fluid in the horizontal wells of coalbed methane in Qinnan area, it shows good stability of the well wall. In combination with the biological enzyme gel breaking fluid, the daily productivity of a single well can be increased by more than 15% while achieving low-temperature gel breaking, which has good reservoir protection effect. After the application of guar gum drilling fluid in the horizontal wells of coalbed methane in Qinnan area, it shows good stability of the well wall. In combination with the biological enzyme gel breaking fluid, the daily productivity of a single well can be increased by more than 15% while achieving low-temperature gel breaking, which has good reservoir protection effect. The research shows that guar gum drilling fluid can realize the smooth drilling of long horizontal section in coal seam, and can break the gel at low temperature after drilling, which provides a new reservoir protection method for the drilling of horizontal well in collapsible coal seam.
Application of Precise Dynamic Pressure Control Well Cementing Technology in Hutan-1 Well
WANG Jingpeng, ZHANG Wei, WU Jiwei, WEI Ruihua, MA Jinming, YANG Hu
 doi: 10.11911/syztjs.2022021
[Abstract](33) [FullText HTML](7) [PDF 2215KB](2)
There are some cementing problems in the deep layer of the southern margin of Junggar basin, such as active oil, gas and water, deep burial, high temperature and high pressure, narrow safety pressure window and so on. Using conventional cementing technology is easy to lose circulation, resulting in cementing failure or unqualified quality. In Hutan-1 well with multiple reservoirs, coexistence of high and low pressure, long sealing and solid section (4069 m) and long open hole section (1907 m), the fine dynamic pressure control cementing technology is applied to successfully solve the problem of multi pressure system cementing in the oil and gas well section of the same open hole section. The fine pressure control cementing technology test includes: designing the construction scheme and parameters from the aspects of wellbore preparation, casing running technical measures, annulus slurry column structure design, injection displacement parameters, loss of circulation well control risk prediction, solid completion annulus plus back pressure, etc., and implementing the wellhead fine pressure control by reducing the hydrostatic column pressure and using the fine pressure control drilling equipment to ensure that the wellbore dynamic pressure is between the formation pore pressure and leakage pressure, Finally, the whole process of fine dynamic pressure control cementing is realized. Hutan 1 well Φ The successful cementing test of 139.7mm liner shows that fine pressure control cementing can effectively improve the cementing quality of ultra deep wells with long sealing section and narrow safety pressure window, and provide technical support for deep oil and gas exploration in the southern margin of Junggar Basin.
Investigation on the Productivity Model and Seepage Rule for the Reservoirs by Broadband Fracturing in Changqing Oilfield
LI Jianhui, LI Xiang, YUE Ming, DA Yinpeng, DONG Qi, CHANG Du
 doi: 10.11911/syztjs.2022085
[Abstract](26) [FullText HTML](21) [PDF 1999KB](2)
The ultra-low permeability reservoirs in Changqing Oilfield are of tight structure, strong heterogeneity and poor performance. The technique of broadband fracturing is adopted by the Oilfield to promote the development effectiveness. The objective that the oil production increases and water content decreases in well pattern is achieved through broadband fracturing. However, the current study rarely focuses on the establishment of the theoretical model of production capacity for well pattern, and the water-driving mechanism cannot be clearly perceived. Therefore, the target of this paper is to evaluate the effect of improving productivity by broadband fracturing, and further reveal the seepage rule for diamond well pattern. According to the flowing morphology of oil-water two phase liquid, the seepage physics field are divided into three districts around injector well, which are linear flow in main fracture, ellipse flow in broadband zone, and circular radical flow in matrix zone, respectively. Furthermore, based on the method of equivalence flowing resistance, the productivity model for diamond well pattern of inverse nine-spot is formed when the fluid flow is considered to be non-Darcy seepage. Taking the practical well pattern as an example, the effect of broaband width and permeability on the productivity of well pattern are analyzed by numerical computation. The various discipline of daily liquid production is explored. The results show that the oil production, extraction extent and the daily liquid production dramatically boost after broadband fracturing. Therefore, this measure enhances the lateral spreading volume, facilitates the homogeneity of water driving and increases the productivity. This paper provides the theoretical support for the oilfield optimizing the craft of broadband fracturing.
Digital Separate Injection Technology of Pre-set Cable for Underground Flexible Composite Pipe
YANG Lingzhi, ZHOU Zhiping, YANG Haien, LI Falong, HU Gaixing
 doi: 10.11911/syztjs.2022057
[Abstract](26) [FullText HTML](6) [PDF 2608KB](5)
In order to improve the qualification rate of separate layer water injection in low permeability oilfield and realize the dynamic real-time monitoring of separate layer water injection, through string structure design, structural material optimization and theoretical analysis, the digital separate injection technology string and key tools of pre installed cable for downhole flexible composite pipe are developed, and the technical problems such as external pressure resistance of flexible composite pipe are solved. The relevant performance analysis and indoor performance evaluation are carried out, The underground flexible composite pipe water injection technology suitable for separate layer water injection is formed. Four wells have been tested in the field. The longest service time is more than 2 years. The qualified rate of stratified water injection is 100%. The data monitoring period is 30 minutes. The results show that the preset cable digital separate injection technology has the functions of layered flow automatic measurement and adjustment, remote seal inspection, data monitoring, etc; The pre-set flexible composite pipe can effectively protect the cable and avoid the collision failure during the operation; The downhole flexible composite pipe meets the requirements of packer setting, backwashing and later testing. It can be seen that the digital separate injection technology of underground flexible composite pipe preset cable can meet the requirements of all-weather separate injection and good corrosion resistance, and has broad application prospects.
Development and Analysis of Force on Blade and Drilling Pressure Distribution of Multistage Diameter Changing while Drilling Reamer
WANG Zhanwen, ZHANG Hong, SHI Lei, FENG Yun, TU Yiliu
 doi: 10.11911/syztjs.2022044
[Abstract](26) [FullText HTML](26) [PDF 2448KB](6)
Aimed at the problems of fixed reaming aperture and low reaming efficiency in reaming operations of reamer while drilling at home and abroad, based on the working principle of reamer while drilling structure and the application of new diameter changing structure, a multistage hydraulic reamer while drilling tool was developed. The functional relationship between the reamer size and the axial displacement of the active piston was established, the force analysis of reamer blade was also carried out, and the weight distribution of the tool was analyzed by using the two-factor calculation method, and the influence law of the weight distribution ratio of the reamer with the reamer size, drilling tool sharpness and formation compressive strength was obtained. The analysis showed that the drilling pressure ratio of the reamer was positively proportional to the formation compressive strength, positively proportional to the size of the reamer, and inversely proportional to the sharpness of the reamer. The theoretical diameter expansion rate of the reamer was 7%−20%. It was concluded that the weight distribution analysis of reamer can guide the design of reamer and the selection of lead bit, and the designed multistage reamer tool can provide effective technical support for improving reaming efficiency.
Present Situation and Development Suggestions of Shale Gas Electric Fracturing Technology in SINOPEC
LIU Honglei, ZHOU Linbo, CHEN Zuo, BO Qiwei, MA Yusheng
 doi: 10.11911/syztjs.2022100
[Abstract](35) [FullText HTML](8) [PDF 2562KB](4)
China is rich in shale gas resources. Because its reservoir permeability is low to the nanometer level, it requires high-power fracturing construction equipment to carry out large displacement and large-scale fracturing construction to generate complex volume fractures to realize large-scale production increase and commercial development. Diesel driven Fracturing Truck Group has played an important role in the large-scale development of shale gas in China. With the progress of technology and people's increasing requirements for environmental protection, the disadvantages of traditional diesel driven Fracturing Truck Group, such as large construction noise, high energy consumption and wide land occupation, have gradually emerged. The electric fracturing equipment has been gradually applied on a large scale due to its advantages of high power, large displacement, low noise and energy consumption and small construction land occupation. This paper summarizes the development and application history and characteristics of electric fracturing technology at home and abroad, focuses on the field application scale, timeliness and cost of Sinopec, analyzes the existing shortcomings, and puts forward suggestions on comprehensively upgrading the electric fracturing system, strengthening construction process management, and large-scale promotion and application of all electric fracturing technology, which will provide economic and low-carbon construction means for deep and normal pressure shale gas development.
Research of Boundary Correction Coefficient of Horizontal Wells in Narrow Channel Reservoirs
YUAN Jianwei, LIU Meijia, LI Chao, WU Chunxin, MA Dong
 doi: 10.11911/syztjs.2022056
[Abstract](31) [FullText HTML](11) [PDF 1723KB](1)
In order to accurately evaluate the productivity of horizontal wells in narrow-channel reservoirs, and to avoid too large evaluation results due to short Drill Stem Testing (DST) time, a boundary correction coefficient was introduced to characterize the effect of channel width on horizontal well productivity. Taking the horizontal well as the research object, the seepage model of the horizontal well in the narrow channel reservoir is established and solved, and the curve of the boundary correction coefficient with the test time under different channel widths is obtained. The research results show that the influence of narrow channel width on horizontal well productivity cannot be ignored. The smaller the narrow channel width, the smaller the boundary correction coefficient. This study was used to evaluate the productivity of 2 horizontal wells in Bohai X oilfield. The evaluation results were consistent with the actual production situation, and the evaluation results were relatively reliable. This method can provide a theoretical basis for the productivity prediction of horizontal wells in similar narrow channel oil reservoirs, and guide the rational production allocation of the reservoir.
2022, 50(5): -1-0.  
[Abstract](0) [PDF 5099KB](1)
2022, 50(5): 0-1.  
[Abstract](0) [FullText HTML](0) [PDF 377KB](0)
Expert Viewpoint
The up to Date Technologies of Ultra-Deep Well Drilling in Junggar Basin and Suggestions for Further Improvements
HE Licheng, TANG Bo
2022, 50(5): 1-8.   doi: 10.11911/syztjs.2022092
[Abstract](27) [FullText HTML](14) [PDF 1577KB](3)
Deep and ultra-deep oil and gas resources have become a new critical area of the exploration and development of oil and gas resources in Junggar Basin. With the increase of drilling depth, the geological conditions of the formation become more and more complex. As a result, the challenges of drilling safely and efficiently are growing. Based on the progress of deep and ultra-deep well drilling technologies in Junggar Basin, the main causes of lost circulation, kick, borehole collapse, and low rate of penetration (ROP) were analyzed, considering the characteristics of the basin geological structure, pressure system distribution, and formation lithology. Furthermore, the technical advances in casing program optimization, managed pressure drilling, wellbore stability, ROP enhancement and other aspects in recent years were summarized. Meanwhile, the drilling situation of 39 ultra-deep wells in Junggar Basin and the existing technical shortcomings were analyzed. Based on the above analysis results, some suggestions to enhance the ability to describe drilling geological environment, enrich wellbore strengthening technologies, and deepen efficient rock breaking technologies were put forward. The research results could promote the development of ultra-deep well drilling technologies in Junggar Basin.
Drilling & Completion
ROP Improvement Technology for Horizontal Shale Oil Wells in Daqing Oilfield
LI Yuhai, LI Bo, LIU Changpeng, ZHENG Ruiqiang, LI Xiangyong, JI Bo
2022, 50(5): 9-13.   doi: 10.11911/syztjs.2021085
[Abstract](52) [FullText HTML](20) [PDF 1628KB](10)
Technical difficulties including borehole wall instability, large friction torque, and long drilling cycles are encountered while drilling horizontal shale oil wells in the Gulong Block of Daqing Oilfield. For the purpose of efficient and rapid development of shale oil, a series of research works have been carried out. In light of the formation characteristics and drilling construction difficulties of the block, a third-spud casing program was optimized to ensure safe well construction in the target shale formation. According to drilling practices and existing techniques, the wellbore trajectory was upgraded to reduce the construction difficulty. In addition, the research was performed considering the hole shrinkage in the second-spud vertical section and the long drilling cycles in the third-spud build-up and horizontal sections. The research was performed on the tools and technologies, such as borehole wall dressing tools, rotary screws, sand cleaning joints, and hydraulic oscillators, and the drilling parameters were optimized. Finally, a rate of penetration (ROP) improvement technology for horizontal shale oil wells in Daqing Oilfield was developed. Field tests were conducted in three horizontal wells in Daqing Oilfield, with an average well depth of 4 691 m, an average drilling cycle of 35.23 d, and an average ROP of 19.03 m/h (enhanced by 53.7%). The research and tests demonstrate that this technology can provide technical support for the efficient development of shale oil in Daqing Oilfield.
Safe Drilling and Completion Technologies for Ultra-Long Horizontal Section of Tight Gas Horizontal Wells in Changqing Oilfield
SUN Huan, ZHU Mingming, ZHANG Qin, SHI Chongdong, WANG Qingchen, QU Yanping
2022, 50(5): 14-19.   doi: 10.11911/syztjs.2022095
[Abstract](25) [FullText HTML](5) [PDF 1976KB](4)
In order to enhance the efficient development of tight gas, Changqing Oilfield has scaled up the deployment of horizontal wells with a horizontal section over 4 000 meters. However, with the increase of horizontal section, technical challenges are encountered, including bad well trajectory control, hard sand transportation by drilling fluids, tight hole while tripping, unstable mudstone hole section, and uneasy setting of tail pipe into designed depth. Therefore, the bottom hole assembly(BHA) optimization and strength check technologies were employed to ensure a safe operation, and a environment-friendly high-performance water-based drilling fluid system combined with the borehole cleaning and monitoring technology was developed to realize the safe drilling of ultra-long horizontal sections. The casing running technology of rupture disk levitating device was applied to ensure a smooth casing operation. Furthermore, a series of specific technical measures were proposed based on the actual situation of oilfield. Therefore, the safe drilling and complement technologies for ultra-long horizontal sections of tight gas horizontal wells in Changqing Oilfield came into being. The technologies have been applied in the ultra-long horizontal sections of 3 tight gas horizontal wells in Changqing Oilfield, with successful well completion, which showed that the technologies could effectively ensure the safe construction of ultra-long horizontal sections. The successful applications show that the technologies can provide technical mothodology for efficeent development of tight gas wells in the Changqing Oilfield.
Key Drilling Technologies for Horizontal Wells with Ultra-Long Horizontal Sections in Nanchuan Shale Gas Field
JIANG Zhenghua, SUN Gang, CHEN Shikui, LI Boyao, DONG Hongye
2022, 50(5): 20-26.   doi: 10.11911/syztjs.2022045
[Abstract](29) [FullText HTML](7) [PDF 1801KB](5)
The application of horizontal wells with ultra-long horizontal sections can improve the economic benefit of normal pressure shale gas in Nanchuan Shale Gas Field. However, there were many technical challenges with this technology, such as difficulties in predicting the ultimate extension capacity of horizontal sections and controlling wellbore trajectory, poor wellbore cleaning, large friction and torque, laborious casing running, frequent cementing leakage, and easy gas channeling, etc. Therefore, the pipe string mechanics and fluid mechanics were analyzed. Then, the force state of pipe strings during drilling and casing running in ultra-long horizontal sections was defined. Meanwhile, the hydraulic extension capacity of the ultra-long horizontal sections as well as the key influencing factors were analyzed. On the basis of the analysis results and drilling practices in Nanchuan Shale Gas Field, a group of key technologies were developed, such as wellbore trajectory optimization design, low-cost but efficient steering drilling, efficient wellbore cleaning, safe casing running, and foam cementing in ultra-long horizontal sections, etc. The above technologies were applied in two horizontal wells with horizontal section lengths exceeding 3 500 m. The whole drilling process was achieved by using drilling bits and positive displacement motors (PDMs) made in China as well as conventional logging while drilling (LWD). The average time for drilling and completion of the two wells was reduced by 25.4% compared with the design value, and the overall target frame of the actual drilling was controlled within 5 m. The encountering rate of high-quality shales and the compound drilling ratio in horizontal sections were above 90% and 90.45% on average, respectively. The maximum dogleg angle was 0.15°/30 m. It is not hard to see that the application of these technologies ensured efficient well construction while achieving increasing drilling speed and cost reduction. The key drilling technologies for horizontal wells with ultra-long horizontal sections in Nanchuan Shale Gas Field can provide a reference for speeding up the drilling of horizontal wells with a horizontal section length exceeding 3 500 m in China.
Key Drilling Technologies for the Ultra-Deep Well Tashen 5
WANG Jianyun, HAN Tao, ZHAO Kuanxin, ZHANG Lijun, XI Baobin, YE Xiang
2022, 50(5): 27-33.   doi: 10.11911/syztjs.2022074
[Abstract](70) [FullText HTML](25) [PDF 2138KB](11)
Well Tashen 5 was deployed to explore the development characteristics and hydrocarbon contents of the Cambrian Shayilike Formation, Xiaoerbulake Formation and the Sinian Qigebrak Formation. Related data indicates that the ultra-deep Well Tashen 5 have several technical difficulties in drilling, such as lost circulation due to fractures and cavities, well deviation due to large formation inclination, and low rate of penetration (ROP) caused by the highly compacted siliceous dolomite. For the lost circulation problem, temperature resistant plugging materials were selected. The ratio and particle size of the plugging materials were optimized to gradually increase the pressure-bearing capacity of the formations while employing the plugging-while-drilling method and progressive plugging methods. In order to solve the conflict between the wellbore quality control and ROP enhancement, the vertical drilling tools and high-torque positive displacement motor (PDM) were applied for deviation prevention and ROP enhancement. In order to solve the problems of low drillability and high abrasiveness of the dolomite formation, the damping and wear-resistant PDC bit and torsion impactor were selected to match with high-torque PDM with iso-wall thickness for compound drilling. Well Tashen 5 was successfully completed after applying above key drilling technologies and provided technical methods and experiences for subsequent drilling in the Cambrian and Sinian of Tahe Oilfield.
Research and Applications of Automatic Cementing Technology Based on the AnyCem® System
JIANG Le, CHENG Sida, DUAN Hongchao, ZHANG Huaiwen, DU Fu, LI Yong
2022, 50(5): 34-41.   doi: 10.11911/syztjs.2022024
[Abstract](74) [FullText HTML](34) [PDF 2182KB](4)
China’s cementing software is mostly imported, and the automation level of cementing equipment is low. As a result, the cementing information management capabilities is insufficient. Therefore, in order to solve these problems, this paper studied the multi-equipment collaborative control method and the whole-process flow automatic monitoring method, and developed a major new automatic monitoring cementing equipment to achieve a multifunctional and integrated cementing system (AnyCem®). As a result, a novel automatic cementing technology was formed, and a whole-process automatic cementing operation was achieved. Further, the technology has been applied in 85 wells in Liaohe Oilfield and Changqing Oilfield as well as Southwest and North China oil and gas fields, with the construction parameter monitoring accuracy rate reaching 100%. Furthermore, the cement slurry density control accuracy is 0.01 kg/L, and the cement head gate and valve operation can be completed within 2s, with the cementing operation accuracy improved by more than 80%. Research and applications show that through the integrated software and hardware interaction, the automatic cementing technology based on the AnyCem® system has achieved the prediction of complex cementing situations, the control of the cementing process, and the assurance of high cementing quality. In addition, it has achieved scientific cementing design and accurate operation and thus can efficiently support complex deep and unconventional oil and gas resource exploration and development.
Numerical Simulation of the Effects of Eccentric Rotation of the Drill String on Annular Frictional Pressure Drop
TIAN Ye, JIANG Donglei, MA Chuanhua, XU Yilong, YU Xiaodong, SONG Xuncheng
2022, 50(5): 42-49.   doi: 10.11911/syztjs.2022104
[Abstract](35) [FullText HTML](6) [PDF 2920KB](7)
Accurate prediction of the annular frictional pressure drop under eccentric rotation of drill string is an important theoretical basis for managed pressure drilling (MPD) in complex structure wells. However, the conventional calculation methods for the annular frictional pressure drop of drilling fluid cannot be directly applied to calculating the annular frictional pressure drop in complex structure wells. For this reason, the influences of eccentricity (0−67.42%) and the rotational speed (0−114.65 r/min)of the drill string on the frictional pressure drop gradient in a typical annulus (created by a ϕ127.0 mm drill pipe and a ϕ215.9 mm wellbore) were analyzed. The results show that when the eccentricity is lower than 45.00%, the rotational speed and eccentricity have a weak influence on the frictional pressure drop gradient. Specifically, the frictional pressure drop gradient decreases slightly with the increase of rotational speed but increases with the increase of eccentricity; when the eccentricity is higher than 45.00%, the frictional pressure drop gradient decreases with the increase of eccentricity at low rotational speed(<60 r/min), and the friction pressure drop gradient increases slightly with the increase of eccentricity at high rotational speed (>60 r/min). According to the numerical simulation results, a dimensionless frictional pressure drop gradient prediction model with eccentricity classification was built. The equivalent circulating density (ECD) of ϕ215.9 mm section of a horizontal well in the South China Sea was calculated by the proposed model. The results were then compared with the pressure-while-drilling (PWD) test results, with an average relative error of 0.45%, indicating that the proposed model has favorable accuracy. This study concludes that the proposed calculation model of the dimensionless annular frictional pressure drop under eccentric rotation can precisely describe the annular pressure field and ECD, and provide guidance for the hydraulic parameter optimization of MPD.
Enhanced Tight Plugging Water-Based Drilling Fluid Technology for Hard and Brittle Shales in Junggar Basin
LIU Junyi, CHAI Jinpeng, LI Guangquan, WANG Baotian
2022, 50(5): 50-56.   doi: 10.11911/syztjs.2022022
[Abstract](53) [FullText HTML](23) [PDF 1838KB](6)
In order to solve the problem of wellbore instability in hard and brittle shale formations in Junggar Basin, the characteristics of mineral compositions and structural fabric of shale were analyzed, and the technology strategy with multi-scale tight plugging as the core was proposed according to the multivariate synergistic principle for wellbore stability. Furthermore, water-based drilling fluids (YHDF-1, YHDF-2) with multi-scale tight plugging were developed. From the analysis results of the mineral compositions and structural fabric characteristics, it is known that the wellbore instability of hard and brittle shales was closely related to its multi-scale characteristics of “microfracture–fissure–pore”. Therefore, the wellbore stability could be enhanced by plugging micro-nano scale fractures, improving shale hydration inhibitive ability, and offering effective stress support of drilling fluids with reasonable density. Performance evaluation results showed that YHDF-1 and YHDF-2 drilling fluids could withstand a high temperature up to 150 °C, and their PPA filtration volumes in a 400 mD sand disc were 17.8 mL and 13.2 mL respectively, with the shale permeability reduced by above 90%. YHDF-1 and YHDF-2 drilling fluids were applied in the drilling operation of Well D-72 and D-12 in Junggar Basin, and no wellbore instability occurred during the drilling process. The average well diameter enlargement rate was lower than 10% in all the test well sections, and the electrical logging was achieved successfully at a time. Research and field tests show that YHDF-1 and YHDF-2 drilling fluids exhibit excellent performance in plugging and collapse prevention, and can be used to deal with the wellbore instability of hard and brittle shale in Junggar Basin.
Integrity Assurance Technologies for Plugged Wells in Wen 23 Gas Storage
WU Junxia, YI Weikai, SUN Peng, LIU Huanle
2022, 50(5): 57-62.   doi: 10.11911/syztjs.2022027
[Abstract](26) [FullText HTML](6) [PDF 1895KB](7)
As Wen 23 Gas Storage is a depleted sandstone gas reservoir, old wells that can no longer be reused need to be plugged before its construction. To guarantee the effectiveness of plugging old wells and assure the integrity of the gas storage, the design concept of wellbore integrity of the technical standard formulated by the Norwegian Oil Industry Association was adopted, and risks of channeling and leakage before and after plugging of the old wells in Wen 23 Gas Storage were identified. Furthermore, a well barrier system was drawn, a heat-resistant swelling-delayed gas-tight plugging system suitable for high-temperature gas layers was developed, and process designed to ensure the wellbore integrity of plugged old wells was created. Assurance technologies for wellbore integrity based on the design, construction, and monitoring of the well barrier were thus obtained and then applied to plug the old wells in Wen 23 Gas Storage. In addition to achieving a 100% success rate of field construction and favorable wellbore integrity after plugging, these wells also survived the long-standing action of alternating stresses during multiple rounds of injection and production. The research results and field application show that conducting wellbore integrity-oriented design and construction according to wellbore integrity can not only ensure the long-term wellbore integrity of old wells after they are plugged but also provide a reference for the design of similar gas storages.
Analysis and Testing of the Working Characteristics of a Pulsating Torsional Impact Drilling Tool
WANG Wei, LIU Gonghui, LI Jun, ZHA Chunqing, LIAN Wei, XIA Mingli
2022, 50(5): 63-69.   doi: 10.11911/syztjs.2021101
[Abstract](101) [FullText HTML](75) [PDF 2605KB](11)
A pulsating torsional impact drilling tool was designed to provide a polycrystalline diamond compact (PDC) bit with a circumferential impact load to suppress the stick-slip vibration of the bit when it drills into hard formations. First, the structural design of the drilling tool was introduced, and its working principle was analyzed. Then, on this basis, mathematical models were established for calculating its impact energy in vertical wells and circumferential torque. Finally, the working characteristics of the drilling tool were analyzed. The analysis results showed that the circumferential torque of the pulsating torsional impact drilling tool increased with the increase in flow rate and decreased with the increase in the diameter of the throttle nozzle. Its impact energy in vertical wells became higher with the increase in the torque and rotation of the drill string; however it declined as the weight on bit (WOB) increased. The performance of the pulsating torsional impact drilling tool prototype was explored through laboratory tests. The test results were positive and indicated that the drilling tool could achieve high-frequency torsional impact, and its operating frequency, circumferential cavity pressure difference, and circumferential torque were all enhanced with the increase in flow rate. The research and test results demonstrate that the pulsating torsional impact drilling tool has an acceptable structural design, which can provide periodic torsional impact loads for PDC bits and suppress the stick-slip vibration.
Preparation and Evaluation of Thermosensitive Plugging MaterialsBased on Shape Memory Polymers
TANG Longhao, WANG Yanling, ZHANG Chuanbao, XU Ning
2022, 50(5): 70-75.   doi: 10.11911/syztjs.2022023
[Abstract](40) [FullText HTML](32) [PDF 1910KB](7)
Considering the insufficient ability of traditional plugging materials to seal fractured leakage, shape memory polymers (SMPs) were introduced for plugging. A thermosensitive plugging material was prepared based on SMPs for their “temperature-controlled deformation” property. Then, its glass transition temperature and shape memory performance were evaluated by the thermo-mechanical dynamic analyzer and shape recovery test. Moreover, the simulation tests of fracture plugging were carried out to assess the plugging capability of the polymers on fractures and explore the plugging mechanism. The research results indicated that the deformation temperature(glass transition temperature) of the thermosensitive plugging material could be regulated in the range of 80–120 ℃ according to the locations of the leakage layers, featuring excellent shape memorizing performance (with a shape recovery ratio of more than 95%). In addition, the temperature resistance of this material was good, with the initial pyrolysis temperature between 230 and 258 ℃, which meant that the material could be applied in a formation temperature environment of 80–120 ℃. The compound of this material and the traditional plugging material could successfully seal the fractures with width ranging from 3–5 mm. The research results can provide a reference for the preparation and application of this new material to fracture plugging.
Oil & Gas Exploitation
Development and Performance Evaluation of an Electrically Controlled Intelligent Water Control and Oil Recovery Tool for Offshore Oilfields
YANG Shukun, GUO Hongfeng, HAO Tao, ZHAO Guangyuan, DU Xiaoxia, LI Xiang
2022, 50(5): 76-81.   doi: 10.11911/syztjs.2022086
[Abstract](14) [FullText HTML](10) [PDF 2914KB](1)
An intelligent water control and oil recovery tool with electrical control was developed to tackle the separate-layer water control and oil recovery difficulties of production wells in the high water cut stage of Bohai Oilfield and to improve the effect of oil production stabilization in the development of production wells. In designing the tool, a single-core cable was employed to ensure the power supply and communications, and multiple test channels in parallel were adopted to achieve real-time testing of the flow rate, water cut, temperature, and pressure. In addition, the ultrasonic time difference method was used to test the fluid production from a single layer, and the radio frequency method was applied to test the water cut in the fluid production of a single layer. With this tool, a real-time control could be achieved according to the water cut of each layer, and the water control and oil production stabilization could be achieved in the development of production wells. The performance tests of this tool demonstrated that the seal performance was reliable under 60 MPa, and it could operate normally at 120 ℃. The test range of water cut was from 0 to 100%, and the measuring accuracy was high for high flow rate, which satisfied the requirements of offshore oilfield applications. The developed tool provides a new water control tool for separate-layer oil production and the efficient and stable development of offshore production wells, and lays a foundation for its subsequent field application in offshore oilfields.
A Method for Rapidly Predicting Recovery of Multi-Layer Oilfields Developed by Water-Flooding
HOU Yawei, LIU Chao, XU Zhongbo, AN Yuhua, LI Jingling
2022, 50(5): 82-87.   doi: 10.11911/syztjs.2022102
[Abstract](23) [FullText HTML](16) [PDF 1981KB](2)
In order to quickly and accurately predict the recovery of oilfields developed by water flooding, a method for rapidly predicting oil recovery was established based on a back propagation (BP) neural network optimization algorithm with consideration of factors influencing the recovery, such as reservoir characteristics and fluid properties. Firstly, geological models for numerical reservoir simulation were constructed according to the geological characteristics and fluid properties of Penglai 19-3 Oilfield. Four key factors including coefficient of permeability variation, oil viscosity, net to gross ratio of oil layers, and production pressure differential were selected, with each factor defined into five levels. 625 groups of reservoir simulation cases were analyzed numerically, and a database indicating the relationship between the oil recovery of the cases and the influencing factors was established. Secondly, an artificial neural network (ANN) method for rapidly predicting oil recovery was set up based on BP neural network and optimization theory. Finally, 500 groups of data were selected as the algorithm training set, and 125 groups of data were tested for recovery predicting. The test result showed that the predicted oil recovery of the tested data had a relative error ranging from −2.91% to 5.07% with an average relative error of 0.16%, which met the requirement for engineering accuracy. The method for rapidly predicting recovery of multi-layer oilfields developed by water-flooding provides a new technical approach to rapidly predict the recovery of Penglai 19-3 Oilfield and other similar oilfields.
Performance Evaluation of Sand Control Materialof Swelling Shape-Memory Particles
KUANG Shaohua, LYU Min, YANG Hong, WANG Lei, TONG Shanshan
2022, 50(5): 88-93.   doi: 10.11911/syztjs.2022101
[Abstract](44) [FullText HTML](10) [PDF 2502KB](6)
To solve the problem of sand production that occurs during oil and gas well exploitation, a new sand control method of filling perforation channels with a temperature-sensitive shape-memory polymer was proposed with the goals of simplifying the construction procedure, reducing sand control cost, and prolonging the effective period of sand control. Shape-memory polyurethane foam was selected as the raw material, processed into irregular particles of 3–6 mm in particle size, then coated with epoxy resin and curing agents on the outer surface. A sand control material of swelling particles was thus prepared, and its swelling performance, temperature resistance, compressive strength, flow performance, sand retention, and medium resistance were evaluated by testing. The results showed that this sand control material started to swell at the temperature of 60–70 °C and its maximum adaptive temperature was 90 °C. With a swelling coefficient of 200%, this material could form a monolithic sand retention barrier after it swelled and cemented in a confined space. The barrier exhibited a compressive strength of 4.5 MPa and a permeability of 90 D. It is capable of retaining formation sand above 0.15 mm in particle size. The flow performance and anti-clogging ability of the proposed material were significantly superior to those of the sand control material of resin-coated sand. The proposed sand control material deserves promotion and application because the sand retention barrier it forms when applied to sand control is highly permeable, high-strength, and anti-clogging, and sand control with this material has the advantages of low cost, simple construction, and leaving no strings.
Influence Law of Hybrid Plugging of Gravel-Packed Media on Productivityin Natural Gas Hydrate Reservoirs
SAIFULLA Dilmurat, DONG Changyin, LI Yanlong, CHEN Qiang, LIU Chenfeng, WANG Haoyu
2022, 50(5): 94-101.   doi: 10.11911/syztjs.2022055
[Abstract](23) [FullText HTML](6) [PDF 2950KB](0)
The influence brought by the plugging of gravel-packed media on productivity is the key to optimizing the productivity of gravel-packed sand control wells for natural gas hydrate production. Primary consideration was given to the hybrid plugging of gravel-packed media by argillaceous silt and secondary hydrates. For the packing media of artificial ceramsite and quartz sand, medium plugging by argillaceous silt and medium plugging caused by secondary hydrate formation were respectively experimentally simulated, and the plugging processes were systematically analyzed. A productivity prediction model for plugged gravel-packed sand control wells for natural gas hydrate production was built according to the hybrid medium plugging mechanism and the permeability variation law, and a case study was carried out with the proposed model. The results showed that under the conditions of plugging by argillaceous silt and secondary hydrate formation, the permeability of the packing layer decreased by 93% and 98%, respectively. The decrease in the permeability of the packing layer caused by hybrid plugging had a significant impact on productivity, and the productivity ratio of the sand control wells after plugging dropped by 97%. Although packing with gravels of large particle sizes can alleviate the loss of productivity, the effect is insignificant. Instead, optimizing the production system to avoid secondary hydrate formation is the key to preventing hybrid plugging.
Field Test of Fishbone Multi-Branch Hole Stimulation Technology in Bohai Oilfield
SU Jian, DOU Peng, CUI Guojie, ZHU Guowei, ZHONG Sheng
2022, 50(5): 102-107.   doi: 10.11911/syztjs.2022050
[Abstract](68) [FullText HTML](44) [PDF 1898KB](3)
In order to increase the single well production and reduce development costs of fractured reservoirs in the Bozhong Block of Bohai Oilfield, a field test of fishbone multi-branch hole stimulation technology was carried out. The technology is characterized by simple tool structure, convenient construction, and low platform burden which make it suitable for offshore platform operation. As the technology is implemented, multi-branch holes with a length of 12 m can be drilled from the main wellbore to the reservoir at one time, and they can penetrate near-well pollution zones, connect the oil and gas flow channels in near-well zones, and improve the single well production, which has great application potential in increasing the production of fractured reservoirs. To ensure the field test could be carried out smoothly, the first step involved a ground test to analyze the drillability of the rock in fractured reservoirs and the trajectory controllability of multi-branch holes. The hydraulic parameters and construction scheme for the fishbone multi-branch hole stimulation technology were optimized accordingly. Furthermore, the field test was carried out in an exploratory well in the Bozhong block. After the application of fishbone multi-branch hole stimulation technology, the well’s gas productivity index and daily gas production were increased by more than 29% and 20%, respectively. The test results showed that the fishbone multi-branch hole technology can improve the single well production of fractured reservoirs in the Bozhong Block of Bohai Oilfield, and provide technical support for the efficient development in the block with low implementation cost.
Optimization and Downhole Testing of Hydraulic Impact Tools
SUN Lin, ZHANG Lei, LI Xuguang, YANG Junwei, XIONG Peiqi
2022, 50(5): 108-111.   doi: 10.11911/syztjs.2022052
[Abstract](32) [FullText HTML](11) [PDF 1483KB](2)
The current hydraulic impact technologies face various problems such as poor adaptability of associated tools in limited well conditions with unstable performance, and the mechanism of the technologies remains untested or verified. Therefore, the hydraulic impact tools were optimized and tested downhole according to the reservoir and engineering characteristics of offshore oilfields. A hydraulic impact tool customized to offshore oilfields was developed by optimization of its size, material and compressive strength, and modification of the key components such as the impact plates. Downhole tests of the hydraulic impact tool were carried out in three wells with low productivity and efficiency in Changqing Oilfield, the formation condition of which was closed to that of offshore oilfields. In the tests, 6–20 pulse wave forms lasting 20–60 s were collected, the main mechanism of the technology was the hydraulic pulse. The test results demonstrated that the optimized tool achieved stable performance and the modified impact plates exhibited higher precision of fracturing pressure as well. These technology significantly enhanced the injectivity of the water injectors. The optimized hydraulic impact tool provides a basis for the application of the technology in offshore oilfields with large wellbores.
Well Logging & Surface Logging
Reliability Study of Anomalies Identified Through Logging by Dipole Shear-Wave Remote Detection in Carbonate Formations
2022, 50(5): 112-116.   doi: 10.11911/syztjs.2022088
[Abstract](62) [FullText HTML](23) [PDF 2404KB](10)
Vertical and horizontal wells were designed and drilled in carbonate formations for the logging by dipole shear-wave remote detection to study the reliability of identified anomalies in logging data obtained by this way. The interpretation results of the logging data revealed that logging by dipole shear-wave remote detection could accurately identify the anomalies and their orientations in the vertical wells in carbonate formations, and their locations identified in horizontal wells were reliable. The logging by dipole shear-wave remote detection for logging were conducted in two wells of Tahe Oilfield and Shunbei Oil & Gas Field, and the locations of anomalies identified through logging were consistent with those from the acid-fracturing treatment curves. The research results indicate that logging by dipole shear-wave remote detection can accurately identify anomalies in carbonate formations, which can provide support for the evaluation and development of carbonate reservoirs.
Application of Rigid HTHP Pipe-Conveyed Memory Logging Systemin Ultra-Deep Wells
ZHANG Zhengyu, YUAN Jun, LI Yangbing
2022, 50(5): 117-124.   doi: 10.11911/syztjs.2022079
[Abstract](55) [FullText HTML](19) [PDF 2731KB](9)
In hostile condition wells, such as high-temperature high-pressure(HTHP) ones and ultra-deep and highly deviated ones, etc., conventional logging methods no longer meet the requirements of safe and efficient oil and gas resource development due to technological and instrumental limitations. Therefore, new logging technologies such as pipe-conveyed memory logging system have been employed extensively. Based on the introduction of the constitution of the rigid HTHP pipe-conveyed memory logging system, its technological advantages were summarized. Furthermore, the typical application scenarios and results of this system in ultra-deep wells of Sichuan Basin and Tarim Basin were analyzed. The field applications show that the success rate of the pipe-conveyed memory logging system in the logging of ultra-deep wells is not less than 95% with the shortest operation time. It suggests that the system can effectively solve the logging problems under the conditions of tight hole, lost circulation, and complex wellbore trajectory. Compared with other logging methods, this logging system offers higher logging efficiency and greater operation success rate, therefore, it demonstrates great potential in the logging of complex ultra-deep wells, and its application can be scaled up broadly as well.
Low-Carbon & Emission Reduction
Carbon Emission Reduction Technologies and Operation Management in Petroleum Engineering Abroad: Up-to-Date Status and Implications
JIANG Haijun, GENG Lidong, WANG Xiaohui, GUANG Xinjun
2022, 50(5): 125-134.   doi: 10.11911/syztjs.2022070
[Abstract](41) [FullText HTML](9) [PDF 2425KB](3)
As countries around the world put forward their “dual carbon” targets (carbon peaking and carbon neutrality), the low-carbon transformation of the energy structure has become inevitable, and carbon emission reduction in traditional petroleum engineering operations has attracted the focus of oil companies both in China and abroad. The development strategies of large oil companies and oil service companies abroad for low-carbon transformation were summarized, and the up-to-date carbon emission reduction technologies in foreign petroleum engineering were introduced from the aspects of electrified equipment, downhole tools, downhole fluids, process technologies, and information technologies, etc. Then, the up-to-date status of operation management modes for carbon emission reduction in petroleum engineering abroad were discussed from the perspectives of geological-engineering integration and the “factory-like” drilling mode. China's emission reduction technologies and operation management modes in petroleum engineering have also made substantial progress, although they still have a long way to go compared with their international counterparts. For this reason, some enlightenments for the development of carbon emission reduction technologies in petroleum engineering in China were proposed on the basis of analyzing the up-to-date carbon emission reduction technologies and operation management in petroleum engineering abroad. Specifically, they are conducting solid top-level design for carbon emission reduction technologies in petroleum engineering, stepping up engineering technology innovation for carbon emission reduction, optimizing management modes in petroleum engineering, reinforcing policy support, and accelerating the construction of talent team for carbon emission reduction in petroleum engineering. The results have practical significance for promoting the development of carbon emission reduction technologies in petroleum engineering and accelerating the green and low-carbon transformation and high-quality development of the oil and gas industry in China.
Drilling Technology Challenges and Resolutions in Fuling Shale Gas Field
Niu Xinming
2014, 42(4): 1-6.   doi: 10.3969/j.issn.1001-0890.2014.04.001
[Abstract](6136) [PDF 1006KB](4064)
The Key Drilling Technologies in Fuling Shale Gas Field
Ai Jun, Zhang Jincheng, Zang Yanbin, Xu Mingbiao
2014, 42(5): 9-15.   doi: 10.11911/syztjs.201405002
[Abstract](4643) [PDF 1084KB](4071)
Large-Scale Multi-Stage Hydraulic Fracturing Technology for Shale Gas Horizontal Well JY1HF
Zhou Dehua, Jiao Fangzheng, Jia Changgui, Jiang Tingxue, Li Zhenxiang
2014, 42(1): 75-80.   doi: 10.3969/j.issn.1001-0890.2014.01.015
[Abstract](6605) [PDF 1149KB](4216)
Application of Multi-Well Pad in Unconventional Oil and Gas Development in China
Zhang Jincheng, Sun Lianzhong, Wang Jiachang, Zang Yanbin
2014, 42(1): 20-25.   doi: 10.3969/j.issn.1001-0890.2014.01.004
[Abstract](5155) [PDF 1211KB](4058)
Integration Technology of Geology Engineering for Shale Gas Development
Zeng Yijin
2014, 42(1): 1-6.   doi: 10.3969/j.issn.1001-0890.2014.01.001
[Abstract](5033) [PDF 1065KB](4548)
A New Method for Evaluating Shale Fracability Index and Its Application
Jiang Tingxue, Bian Xiaobing, Su Yuan, Liu Shuanglian, Wei Ran
2014, 42(5): 16-20.   doi: 10.11911/syztjs.201405003
[Abstract](4274) [PDF 1055KB](3733)
Status and Prospect of Multi-Well Pad Drilling Technology in Shale Gas
Chen Ping, Liu Yang, Ma Tianshou
2014, 42(3): 1-7.   doi: 10.3969/j.issn.1001-0890.2014.03.001
[Abstract](4617) [PDF 1031KB](4029)
Development and Reflection of Oil-Based Drilling Fluid Technology for Shale Gas of Sinopec
Lin Yongxue, Wang Xianguang
2014, 42(4): 7-13.   doi: 10.3969/j.issn.1001-0890.2014.04.002
[Abstract](4419) [PDF 1031KB](3676)
Development and Pilot Test of Hydro-Oscillator
Li Bo
2014, 42(1): 111-113.   doi: 10.3969/j.issn.1001-0890.2014.01.022
[Abstract](4152) [PDF 1085KB](4120)
Research Status and Prospect of Hydraulic Oscillator Worldwide
Ming Ruiqing, Zhang Shizhong, Wang Haitao, Hong Yi, Jiang Shulong
2015, 43(5): 116-122.   doi: 10.11911/syztjs.201505020
[Abstract](6403) [FullText HTML](99) [PDF 1272KB](4316)