bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Factors Influencing the Efficiency of Hot Water Injection in Offshore Heavy Oil Reservoirs
Authors: Ma Kui-qian , Feng Hai-chao , Liu Dong , Tan Jie , Zhu Qin
Published: November 2024

In response to the problem of low final recovery rate in conventional water flooding development of offshore heavy oil, the Bohai LD5 heavy oil field was taken as the target area. Through one-dimensional oil displacement efficiency experiments, the influence of crucial injection and production parameters on oil displacement efficiency, such as temperature, injection rate, injection production ratio, timing of hot water flooding, and injection medium, was studied. The key injection and production parameters were optimized, and the main controlling factors affecting the efficiency of hot water flooding after water flooding were identified through data analysis. Propose an optimization approach for thermal injection media and quantitatively evaluate the oil recovery efficiency under different injection and production parameters. Research has shown that for the Bohai LD5 heavy oil field, the optimal combination of injection and production parameters is: an injection rate of 2mL/min, injection temperature of 110°C, and timing of conversion to flooding at a recovery rate of 20% to 30% (water content of 55% to 70%). The hot water composite flue gas has the best oil recovery effect, considering both oil recovery efficiency and on-site construction conditions. The degree of influence of various factors on the efficiency of hot water flooding is as follows: temperature>timing of hot water flooding (recovery degree)>injection rate. Under low temperature (within 110 °C) conditions, temperature is the main factor affecting the efficiency of hot water flooding. The overall recovery rate of different injection media shows a trend of hot water composite>hot water>cold recovery.
Miscibility Evaluation for Reinjection of CO2 Flooding Associated Gas in Jilin Oilfield
Authors: Han Bo , Zhai Zhiwei , Wang Chen , Cheng Zhilin , Li Teng , Li Pan , Zhang Liang
Published: November 2024

In view of large amounts of associated gas produced in the late stage of CO2 flooding in Jilin Oilfield, the production characteristics of CO2 flooding associated gas are divided into three stages (i.e. before injected gas breakthrough, during injected gas breakthrough and after injected gas breakthrough). Taking the formation pressure as miscibility evaluation criteria, the miscibility effect of the produced CO2 flooding associated gas from different stages is evaluated. According to different gas production stages, the reinjection method of mixing the associated gas with pure CO2 under different proportions is proposed to elevate the utilization degree of the produced associated gas. The results indicate that at the very beginning of gas production process, produced gas is mainly composed of CH4 (58%) and C2~C3 (29%) with small amounts of N2 and C4~C6. During this stage, the associated gas can not reach miscibility with the oil by direct reinjection. It needs to be mixed with pure CO2, also the blending ratio of the associated gas should not exceed 6%. In the second stage, the compositions of the produced gas are mainly CH4 (34%) and CO2 (40%). During this stage, the blending ratio should not exceed 11%. At the final stage, the main composition of the produced gas is CO2 (94%). The associated gas can be directly reinjected into the reservoir during this stage.
Experimental simulation of mixed deposition of hydrate and wax in a deepwater subsea pipeline
Authors: Chen Haihong , Yao Haiyuan , Li Qingping
Published: November 2024

Hydrate and wax deposition are the main challenges faced by the safe operation of a deepwater subsea pipeline due to low temperature, large elevation difference, and complex multiphase flow conditions. Chemical agents are important ways for treating hydrate and wax deposits. Oil, gas, and water produced by Liuhua 16-2 Oilfield are selected as experimental media to test and evaluate independently developed pour point depressants, wax deposition plugging removal agents, and low dose hydrate kinetic inhibitors. The static effect test results for three pour point depressants AN-12B, OF-1, and JN106-12B show that JN106-12B has the best performance, which can reduce the pour point of crude oil produced by Liuhua 16-2 Oilfield from 8°C to -19°C. When there is a risk of mixed deposition and blockage of hydrates and waxes during the fluid flow in the loop, simply adding pour point depressants or hydrate kinetic inhibitors cannot reduce the critical temperature at which the loop blockage occurs, and adding only wax deposition and blockage removal agents after the loop blockage cannot achieve blockage removal. However, if thermodynamic hydrate inhibitors such as methanol are added in advance, after the pipeline is blocked by wax deposition, the pipeline can be unblocked by adding the wax deposition unblocking agent JD150-B27. 20000ppm wax deposition plugging remover JD150-B27 takes about 40 minutes to achieve loop plugging removal. The evaluation results of different agents provide an important reference for the prevention and control of hydrate and wax deposition in the subsea pipeline of Liuhua 16-2 Oilfield.
Study on Wellbore Stability of Shale Oil Drilling
Authors: Zhou Guangxu , Yan Chuanliang , Cheng Yuanfang , Han Zhongying
Published: November 2024

With conventional oil and gas development entering the middle and late stage, unconventional oil and gas development is the focus of resource replacement and stable production. The South China Sea is rich in shale oil resources and has great development potential. However, the experience of shale oil exploitation in the South China Sea is not enough. The performance of oil shale rock in the target block is unclear, the anisotropy caused by bedding has great influence, the formation has abnormal high pressure, and various factors affect the wellbore stability. In the process of drilling, complex conditions occur frequently, which seriously limits the efficiency of exploration and development. Therefore, this paper studies the wellbore stability of shale oil drilling in the South China Sea, carries out rock mechanics experiments, analyzes the strength of oil shale rock, and studies the influence of oil-based drilling fluid and anisotropy caused by bedding on rock strength. Combined with logging data, the change law of formation caving pressure is analyzed and formation pressure is predicted. The research shows that the oil shale rock in this area has low strength, the core is hard and brittle, and the core is anisotropic under the influence of bedding. The strength weakening law of oil shale soaked in oil-based drilling fluid is studied, and the formation collapse pressure variation law is further obtained. The fracture pressure, caving pressure and pore pressure of the proposed drilling are predicted, which provides technical support for the safe and efficient drilling of shale oil drilling in the South China Sea.
Review and Prospect of Viscoelastic Surfactant Diverting Acid
Authors: Shi Yiquan , Liu Pingli , Du Juan , Zou Qi , Liu Jinming , Chen Xiang
Published: November 2024

With the rapid development of social economy, global energy demand is growing rapidly. Carbonate reservoirs have attracted much attention due to their wide distribution and large reserves. Due to the heterogeneity of carbonate reservoirs, conventional acidification technology cannot meet the production requirements, and diverting acid must be used to achieve effective development. The biggest problem of commonly used polymer-based diversion acid is the polymer residue after acidification. In recent years, the viscoelastic surfactant diverting acid (VEDA) system has attracted much attention because it can be decomposed by a simple cleaning process after the temporary plugging and diverting acid operation is completed. This paper studies the VEDA system through a large number of literature research. The properties of (VES) were introduced, and the application of viscoelastic surfactant in VEDA was analyzed. Secondly, the working principle of VEDA acid system is listed and several methods for evaluating the diverting ability of VEDA (pressure drop curve, permeability change, wormhole expansion) are introduced. Then, the VEDA rheological model established by various scholars was summarized. Finally, the commonly used VEDA system and its application in this field are summarized.
Research and Application of Online Electromagnetic Wax Prevention Device for Oil Wells
Authors: Zhen Weishi , Gao Baoyuan , Li Huawei , Lin Lieni
Published: November 2024

Wax deposition in oil wells can affect normal production, increase the hanging point load of oil wells, increase system energy consumption, reduce system efficiency and pump efficiency, affect oil well production, and even directly block oil pipes, causing oil well shutdown. Wax deposition in oil wells is one of the prominent problems that affect the high and stable production of oil wells. Wax prevention in oil wells is an important maintenance measure to reduce oil well load, save energy and reduce consumption, and extend the maintenance free period of oil wells. There is an urgent need for a long-term wax prevention technology to prevent wax deposition in oil wells, reduce pipe and rod friction, and reduce hanging point load and load current. We conducted research on the electromagnetic wax prevention online device for oil wells, with a focus on introducing the composition and functions of the electromagnetic wax prevention online device for oil wells, which consists of a high-performance electromagnetic conversion device and a control unit. Through on-site application in 10 oil wells in the Tongzhai operation area of the Third Oil Production Plant in Changqing Oilfield in 2023, an electromagnetic anti wax online device was installed on the wellhead process. The anti wax effect not only affects the downhole process but also the surface process, effectively alleviating wax accumulation in the oil wells, replacing frequent hot washing, adding wax cleaning agents and other technologies, extending the well washing cycle and maintenance free period, avoiding wax blockage of pipelines or wax stuck wells, and effectively controlling production and operation costs, Improve the economic benefits of oil well development.
Research and Application of Online Electromagnetic Heating System with Internal Penetration in Oil Pipeline at Well Site
Authors: Gao Shihui
Published: November 2024

In response to the current situation of heating crude oil in the oil pipeline of Changqing Oilfield, most of the well sites have no associated gas, gas heating furnaces have been discontinued, and coal-fired heating furnaces pollute the environment. A study was conducted on the online through type heating system for the oil pipeline in the well site, with a focus on the composition and function of the digital heating system for the through type oil pipeline in the well site. The through type online heating system for the oil pipeline in the well site is mainly composed of a variable frequency electromagnetic controller The online controller and internal heating cable are composed of three parts. The oil pipeline generates heat by itself, while preventing the crystallization of paraffin and scale in the oil pipeline under the action of alternating electromagnetic fields, which is not easy to form wax. In 2023, on-site application was carried out on two oil pipelines in the Tongzhai operation area of the Third Oil Production Plant in Changqing Oilfield, replacing the existing gas heating furnaces and coal-fired heating furnaces to heat and transport crude oil in the oil pipelines. It does not generate heat itself and has a long service life. Due to the high thermal efficiency of the heat source coming from the inside of the oil pipeline, the buried pipeline renovation can be installed without breaking the soil. The flexible internal cable reduces the difficulty of construction and is safe and environmentally friendly, At the same time, it can remotely monitor the temperature of crude oil in the oil pipeline and the wellhead backpressure online.
Research on Effective Development Methods and Development Potential of Tight and Difficult to Develop Reservoirs in Hailar Oilfield
Authors: Li Wentao , Xiu Zengpeng , Liu Li , Qi Linhai
Published: November 2024

In order to solve the problems of large undeveloped reserves and difficult development in the tight sandstone reservoir of Hailar Oilfield, from the perspective of “revitalizing ineffective and inefficient development wells, effectively utilizing tight reservoirs, and improving oilfield recovery”, with the widespread application of volume fracturing and other technologies, and in line with the principle of “starting with the easy and rich before the difficult and poor” in the development of ultra-low permeability fault block reservoirs, the transformation of tight sandstone reservoirs has been taken as an important supplement to the development and production of oil fields. This article takes the tight sandstone reservoir as the research object, aiming at the characteristics of low reserve abundance, longitudinal non-concentration of oil layers, and scattered development of sand bodies. Through detailed analysis and analysis of regional oil and gas migration systems, reservoir classification evaluation standards, fracturing process optimization, and development models, the potential of reservoir transformation and oil production capacity are systematically evaluated. Effective fracturing and post-fracturing energy-enhancing field tests are carried out for ultra-low permeability elastic mining areas, which have implemented the feasibility of utilizing difficult reservoirs, broken through the technical bottleneck of low production in tight sandstone reservoirs, and developed the theory and supporting technology of tight oil development in Hailar Oilfield. Based on the on-site test results, it is shown that the ultra-low permeability reservoir in Hailar Oilfield has the development conditions, indicating the direction of future development potential.
Characterization of Residual Dispersion in High Water Cut Reservoir
Authors: Fei Liang
Published: November 2024

Minghua Formation in Gangdong Oilfield belongs to high permeability reservoir. The dispersion degree of residual oil is a very important production target. The dominant reserves in reservoirs are extracted by the abundance parameters of residual dominant reserves. The residual oil dispersion degree is characterized by the index of unit area, distribution density and shape index, and the weight of each index is determined by the entropy weight method. Finally, the residual oil fraction is formed. The results show that for a stable reservoir, the residual oil dispersion in different development stages include the following stages: rising, rapid rising, fluctuating downward and secondary rising. The characterization index is used to evaluate the Nm3-4-1 formation of Gangdong oilfield. The residual oil dispersion of the formation increases steadily with the development. At present, the residual oil dispersion begins to decrease. The new characterization method of residual oil dispersion effectively reflects the stage effect of reservoirs and provides a basis for improving oil recovery.
Stability Analysis of Surface Wellhead Retention in Offshore Exploration Wells
Authors: Liu Xun , Li Wenlong , Xu Kun , Yang Baojian , Yue Ming , Tang Baisong
Published: November 2024

When offshore exploration wells are carried out, a narrow operating window and prolonged construction period may be encountered, which may lead to the evacuation of the drilling platform. The conductor will be left freestanding in the sea water, posing a great risk to wellhead stability. In this paper, based on finite element simulation of offshore exploratory well freestanding conductors, the stability analysis method is built and evaluation of a well is carried out. It is concluded that in 1 year return period and sea conditions by hanging load return period of 10 years of sea condition, the stability all meet the conditions, but there in 10 years return period of sea state by hanging load and 50 years return period of sea condition did not meet the requirements of stability. In cases where stability requirements are not met, alternative means of retaining the wellhead are recommended. This study has certain guiding significance for the safe and efficient operation of offshore exploration wells.
Research and Application of Drilling and Completion Technologies on Large-size Injection-production Well
Authors: Wang Jiangkuan , Wang Bo , Gong Yongfeng , Zhao Chun , Chen Xianxue , Feng Xianyan
Published: November 2024

The large-size injection-production well can increase the injection-production capacity to more than 3 times, compared with the conventional-size one. However, it had not been popularized and promoted for many years since it had the technical difficulties of long construction period, high engineering risk and large investment in a single well. The Liaohe double-6 gas storage planned to deploy 3 large-size horizontal wells, aiming at further improving injection-production capacity to satisfy peak shaving demand. To overcome the technical difficulties of large-size well, the drilling scheme was optimized according to geological characteristics of double-6 block in the paper. It included wellbore structure design, wellbore diameter control technology and hole cleaning technology. The optimized drilling scheme can not only improve the wellbore integrity, but also reduce the risk of engineering accidents and shorten the drilling period greatly. Besides, the cementing technology was optimized as well from the aspects of hierarchical cementing and cement slurry design, which can be used to solve the problems of high pressure at the bottom of well and large leaking risk of cement. On the basis, the above drilling and cementing technologies were applied to develop three large-size wells, and good practical results were achieved. The average completion period of the three well was 104 days, 36 days shorter than the planned period, which realized the applying effects that large-size wells can be designed, constructed, and produced in the same year. Moreover, the ultrasonic evaluation results showed that the average qualified rates of the three wells in technical casing was 92.8%, which was much higher than the industry standard. Besides, the test results showed that the injection and production volume of each large-size well in the paper can exceed 3 million cubic meters, solving the problem of insufficient injection-production capacity in the months with high peak shaving demand. Above all, the drilling and cementing technologies of large-size well had been optimized in the paper, which successfully reduced the well completion period, and improve the cementing quality and the safety of drilling construction. The researches can not only ensure the project quality of large-size well in Liaohe double-6 gas storage, but also provide technical support for promoting the drilling and completion engineering of large-size well in other domestic and foreign gas storages.
Application of thin slice technology of loose cuttings sample in early stage of experimental geology
Authors: Xiangpeng Kong , Bihan Qiu , Yanjie Li , Jingsheng Li , Yan Shen , Yuming Wu , Lihong Jin , Yongyi Ma , Pengpeng Sheng , Yang Liu
Published: November 2024

Thin section of rock is a highly technical work in the laboratory, and its application in logging site and rock identification is helpful to solve geological problems quickly in the process of exploration drilling. The cuttings samples cover a variety of lithologies, including sandstone and volcanic rocks with significant diagenetic differences. Due to the special properties of the cuttings, such as loose, fear of water, moisture absorption, brittleness, large hardness differences, inconsistent particle size, and not easy to penetrate glue, the production process has been challenged. In the temperature and humid environment, the cuttings are very susceptible to delixing, especially in the cuttings with cleavage development, more cracks and poor diagenesis. After the sticking sheet is affected by vibration during rough grinding, it is easy to produce warping edge and warping Angle, which leads to the destruction of the original structure of the mineral. The previous production process cycle is long, the operation is relatively not convenient, especially in the grinding into the international standard 0.03mm thick pieces there are certain difficulties. Therefore, it is very important to improve and optimize the rock wafer technology. This will help improve the efficiency of the production of cuttings and reduce the likelihood of damage to mineral structures, which in turn can be used more effectively in exploration drilling sites and rock identification, providing faster and more accurate support for solving geological problems. The results of this study have important significance for improving the efficiency and convenience of the production process and improving the application prospect of the rock sheet technology.
Seismic Characteristics and Distribution Patterns of Maokou Formation Dolomite Reservoirs in The Hechuan Area of Central Sichuan
Authors: Sun Shan , Jiang Na , Li JiPeng , Ju Linbo , Zhang Dazhi , Wang Lijing
Published: November 2024

In recent years, the exploration of dolomite reservoirs of the Permian Maokou Formation in the Hechuan area has made a breakthrough, making the Maokou Formation the main exploration layer in the central part of the Sichuan area. The reservoir lithology of the Maokou Formation in central Sichuan is mainly composed of fine to medium crystalline dolomite and residual granular dolomite. The dolomite reservoir is relatively thin, located in the middle of the second member of Maokou Formation vertically and distributed stably laterally. Based on rock physics, this study analyzes the factors influencing the seismic response characteristics of the dolomite reservoir of Maokou Formation, and makes it clear that the dolomite reservoir shows the characteristics of continuous strong peak reflection in the seismic profile. By analyzing the positive correlation between reservoir quality and amplitude intensity, the amplitude attribute can be used to determine the favorable area of dolomite reservoir development, and the reservoir distribution can be quantitatively described by seismic inversion. According to the seismic attributes, the dolomite reservoirs are distributed in contiguous regions, mainly along the TS3 ~TS4~TS11~MX39, which are distributed in a NW - SE direction. Seismic inversion results further clarify the stable distribution of dolomite reservoirs, with regional contiguous features. Through the study, it is clear that the favorable area of the dolomite reservoir in the second member of Maokou Formation is distributed in the central part of the Hechuan area, and the area of the reservoir is more than 1200km2. Multiple Wells have been deployed to obtain more than one million square meters of industrial air flow, and billions of square meters of proved reserves have been submitted.
Application of stress distribution simulation under fracture in predicting drilling leakage in Bozhong area
Authors: Xu Sheng-Li , Li Hui , Sun Yu-Hong , Zhang Ye , He Shuang-Cheng , Wang Bin
Published: November 2024

Faults and fractures are the most important factors that cause serious drilling leakage. Aiming to meet the production demand of improving the the reliability of leakage prediction, this paper uses the forward modeling technique of stress distribution in fault zones, by forward modeling of different fault combination modes, different scale fault stress influence ranges, and different fault zone filling modes, the stress changes, sizes, distribution characteristics, impact ranges, and properties of the fault zones on both sides of the fault were quantitatively displayed, achieving a comprehensive and quantitative characterization of the stress distribution under the fault; In addition, under the guidance of stress distribution, the reliability of leakage prediction can be improved effectively; Farther more, this paper combined the characteristics of the well-seismic data in the actual fault zone with the distribution of drilling leakage, proves that the three-dimensional space stress simulation and the stress intensity can effectively predict the plane and longitudinal distribution position of drilling leakage. The practicability of the method has been effectively applied and tested in the drilling leakage prediction and tracking in Bozhong area.
Development Characteristics of Single Sand Body of Yan’An Formation in Western Ordos Basin
Authors: Hui Fang , Zhang Tong , Wang Kunpeng , Sun Wei , Wang Bo
Published: November 2024

The precise characterization of the types and spatial distribution of strongly heterogeneous single sand bodies are a necessary prerequisite for the study of oil and gas reservoir formation. This article takes the Yan’an Formation in the western Ordos Basin as an example to systematically study the internal structure and profile distribution of strongly heterogeneous single sand bodies. The research results indicate that using mud interlayers, physical interlayers, and calcium interlayers as layered interfaces can effectively classify the single sand body types of each small layer in the Yan’an Formation. The drilling rate of a single sand body is between 50% and 85%, and the average number of sand layers is between 3 and 8. When two rivers intersect and are horizontally tangent, due to the mutual erosion of water flow, relatively thick sand bodies can be retained, ultimately resulting in a pattern of relatively thick on both sides and thin in the middle. The single sand body at the bottom is the most developed and has good continuity. In the transverse direction of the river, the continuity of a single sand body is relatively poor, and the extension range of a single sand body is 300m to 1200m. Along the river channel, single sand bodies are developed with good continuity, extending about 2km. The connectivity between the sand body and the well varies with the migration of the river in the transverse river profile of the research area. The lateral contact relationship of a single sand body determines the boundary of the river channel, and the profile characteristics of a single sand body also reflect its planar distribution. The intergranular pores of the Yan’an Formation sand body are relatively developed, and a large number of quartz particles offset the compressive stress of the rock. The corrosion of feldspar particles is relatively strong, retaining a large number of primary intergranular pores. There is a good quantitative relationship between the thickness of sand in a single level channel and the width of the channel. The control of the well network on the sand body is relatively small, and there is room for further densification of drilling. The vertical contact relationship of a single sand body in the Yan’an Formation of the research area can be divided into three modes: separation, stacking, and overlapping. Cut pile sand bodies with good connectivity have good production capacity. The different planar contact relationships reflect the degree of connectivity between channel sand bodies and wells, with lateral cutting type>docking type>isolation type. The side cut sand body has uniform longitudinal water absorption, small water absorption difference, and high-water drive degree. The isolation type has the greatest difference in water absorption rate and the lowest degree of water flooding.
Numerical Investigation on Cathodic Protection of X80 Pipeline Steel in Marine Environment
Authors: Wang Shuli , Yao Jing , Hao Chengming , Xiang Xiaosen , Chen YiLin , Rao Yongchao
Published: November 2024

Submarine pipelines are usually buried in sea mud, but part of the pipes will be exposed to seawater directly because of the change of seabed, the differences between sea mud and seawater result in different corrosion states. Generally, due to its large geometric size, complex medium, difficult to detect and other reasons, corrosion defects will cause greater harm to pipeline materials. A numerical analysis model of the outer surface corrosion of submarine pipelines was developed to simulate status of cathodic protection, furthermore, potential distribution and local density of current inside the defects was also analyzed and evaluated. The results indicates that:

(1)The CP potential distributes more evenly in sea mud when the same sacrificial anode is used, and the cathodic protection current density needed to meet the anti-corrosion requirements is much larger in seawater than in sea mud.(2)Compared with sea mud, the polarization potential of the sacrificial anode in seawater is more negative, and the CP potential at the edge of anodes is the most positive in both sea mud and seawater. Furthermore, in seawater, the dissolution rate of sacrificial anodes closer to the seabed is lower, and anodes dissolve much faster at the inner surface, while it is just the opposite in sea mud.(3)Cathodic protection cannot ensure complete and effective protection at defect points. At defect bottom, the cathodic protection current is partially shielded, reducing the effectiveness of CP system on corrosion protection of pipelines. Moreover, the shielding effect of defect point on cathodic protection current has a great deal with the geometric shape of defect points, with decreasing width and increasing depth, the shielding phenomenon becomes more obvious.(4) Numerical simulation technique based on the finite element model provides a new method to solve this problem and plays a positive role in assessing anti-corrosion status and the service life of anodes.
Research on the Mechanism of Nanoparticle materials in Oil Displacement and its Application
Authors: Zhang Yiran , Ma Yishu , Ju Binshan , Li Lingyun
Published: November 2024

The application of nanoparticles in the field for enhanced oil recovery (EOR) is a new technology, which has attracted widespread concern. However, there is a lack of systematic research on the types and mechanisms. In order to clarify the types and characteristics of the material, oil displacement mechanism and its effect on oil and water flow, this paper systematically sorted out the classification of nanoparticle materials used in the field of petroleum development, and analysed its percolation and oil displacement mechanism. Numerical simulation and field data analysis were carried out to study the applications of two types of nanomaterials in improving reservoir water injection and oil displacement efficiency quantitatively. The results show that the main mechanism of nanoparticle flooding is to change reservoir wettability, reduce oil-water interfacial tension, modify the mobility ratio between water and oil phases, and reduce asphaltene precipitation. Lipophilic and hydrophobic nanoparticle may reduce injection pressure, and increases significantly injection in low permeability reservoirs, and the average water injectability of 6 wells is increased by 177.76%. The displacement efficiency of hydrophilic and oleophobic nanoparticles can be increased by 14.78%. This paper reveals the oil displacement mechanism of nanoparticle materials and establishes a new method to quantitatively predict the oil displacement effect of nanoparticle materials, which provides a basis and reference for the application of oilfield.
Application of Microwave Imaging Combined with Electromagnetic & Ray Localization in Pipeline Deformation Detection
Authors: Huang Hai , Dai Zhixiang , Tang Ping
Published: November 2024

This article aims to explore a new type of non excavation pipeline detection method, which combines microwave imaging with electromagnetic and ray positioning methods, to improve the accuracy and efficiency of pipeline detection and accurately locate the deformation of pipelines. [Method]Firstly, the microwave imaging method is used to detect the pipeline, and the deformation of the pipeline is determined by the reflection of the microwave. At the same time, electromagnetic and X-ray positioning technologies are used to accurately locate the pipeline and its deformation situation, in order to more accurately understand the position and deformation of the pipeline. [Result] Through the inspection of actual pipelines, we found that microwave imaging combined with electromagnetic and ray positioning technology has high detection accuracy and reliability, and can effectively detect the deformation or blockage position information of pipelines. Meanwhile, this method also has the advantages of simple operation and fast detection speed.[Innovation]Microwave imaging method combines electromagnetic and ray positioning technology organically, and is a non-contact detection method. It solves the problems of self deformation caused by impact in existing diameter plate methods, damage to pipe walls, and imprecise positioning of pipe deformation positions. This method is expected to be applied to the detection and maintenance of various pipelines, improving the efficiency and accuracy of pipeline maintenance.
Numerical Analysis and Application of Marciniak and Nakazima Experimental Model on the Formability of 304L Sheet
Authors: Zhang Jiguang
Published: November 2024

The comprehensive strength, ductility and high work hardening rate of 304L stainless steel contribute to its excellent mechanical and forming properties. This steel alloy is further distinguished by its notable corrosion resistance, high and low temperature capabilities, and excellent welding performance, making it a widely utilized material in industries such as petroleum, chemical, and nuclear power. In this study, we developed a simulation model based on the testing methods of Marciniak and Nakazima. By incorporating a constitutive model for ductile damage into our simulations, we made predictions regarding strain damage and failure under three different types of strain paths: uniaxial tension, biaxial tension, and plane strain. The results obtained from our finite element analysis were then utilized to generate the Forming Limit Diagram (FLD), which provided valuable insights into the material’s behavior under various forming conditions. Highlighting key differences in the simulation results between the Marciniak and Nakazima test methods. Additionally, the study included a comprehensive simulation verification in the context of bending forming analysis. Notably, the results of the bending analysis fell within the safe range, establishing a solid theoretical foundation for subsequent plate forming and risk assessment.
Experimental Study on the Optimal Operating Envelops of Ejection Supercharging Technology for Unconventional Natural Gas
Authors: Zhou Wei , Jiang Mi , Anqi Du , Zhonghao Dong
Published: November 2024

Ejection supercharging technology could make use of the energy of high pressure gas wells to assist the development of low pressure unconventional natural gas. But at present, the process of adaptability analysis is complicated, the period is long, and the process implementation is difficult in process application. In this paper, based on the production situation of unconventional natural gas, experiments are carried out to investigate the impact of structural and operational parameters on the performance of ejection supercharging. According to analyze the relationship among high, middle and low pressure inlet conditions and their influence on operational performance, as well as the dimensionless processing of pressure parameters, the optimal operating envelops of Ejection supercharging technology for unconventional natural gas is established. Furthermore, A chart is proposed with variable parameters under different conditions to determine the target gas wells for this technology, allowing for a rapid analysis and determination of whether gas wells are suitable for Ejection supercharging technology. And it also get the pressure reduction range of the process acting on the low pressure well, which provides a reference for analyzing the application effect of the process. Finally, The results of the case analysis demonstrate a 100% match rate with the chart established in this paper. The research results greatly simplify the process of well selection, and transform the analysis for specific working conditions one by one into a unified analysis for multiple working conditions, consequently lays a solid foundation for the widespread application of the ejection supercharging technology for unconventional natural gas.
Development and Application of Drilling Intelligent Assistant Decision System
Authors: Wang Jian-long , Wang Yue-zhi , Yu Zhi-qiang , Yu Chen , Zhang Fei-fei , Wang Xue-ying
Published: November 2024

In order to systematically harness the substantial volume of data generated during the drilling process and achieve intelligent analysis and auxiliary decision-making for real-time risk monitoring and warnings during drilling, an intelligent drilling auxiliary decision-making system has been developed. This system integrates various technologies, including physical models, intelligent algorithms, and trend analysis. By analyzing the characteristics of logging data under different operating conditions, an intelligent algorithm capable of automatically distinguishing six types of drilling operating conditions has been established. Taking into account the impact of rock cuttings on the stress on the pipe string and annular pressure loss during the drilling process, coupled frictional torque and cyclic pressure loss calculation models were developed under coupled conditions. Building upon this foundation and considering the trend of deviation between predicted and measured parameters, a monitoring algorithm for detecting stuck drilling, wellbore leakage, and overflow incidents was formulated. The development of the drilling intelligent decision-making system was completed based on a C/S three-layer architecture and a data center. This system has been successfully applied in more than 50 exploration wells of various types, including shale oil and gas horizontal wells and deep wells. The static analysis results demonstrated a compliance rate of 91.5% with on-site monitoring, playing a crucial role in drilling parameter optimization and risk monitoring. The practicality and feasibility of the system have been verified, providing essential support for efficient and safe drilling production.
Investigation the Impact of Different Injection Agents on Tight Oil Reservoirs of Recovery Performance
Authors: Wan Tao , Ding Kun , Qin Jianhua
Published: November 2024

Objectives/Scope: Due to strong water sensitivity and extremely low permeability, conventional water flooding method is not suitable for the Mahu Conglomerate reservoir. In response to the complex reservoir physical properties, different injection agents such as CO2, N2, water and air huff and puff injection were carried out in order to optimize injection parameters for enhanced oil recovery in tight conglomerate reservoirs. Methods, Procedures, Process: By means of NMR, scanning electron microscopy, energy spectrum, pore fluids state in different media after different agents displacement were studied. Displacement and CT testing on different media and post fracturing state were conducted. Through experiments on on-site cores from two different layers, three different injection media (H2O, N2, CO2 and air with different O2 concentration) were tested for enhanced oil recovery. Then, the injection process was performed under different injection pressures. Finally, multiple cycles of enhanced oil recovery tests were conducted corresponding optimal injection pressures. Results, Observations, Conclusions: The remaining oil in the pores is mainly in free and bound states, with a free state of approximately 58% and a bound state of approximately 42%. Four pressures were selected for this test based on the minimum miscibility pressure of CO2 with crude oil: 15MPa, 20MPa, 23MPa, and 25MPa. The recovery factor under different pressures is 6.44%, 8.14%, 10.31%, and 10.38%, respectively. As the huff and puff pressure increases, the recovery of CO2 huff and puff gradually increases, and the increase of recovery is insignificant when the mixture pressure is reached. The gas flooding process involves oil production from large and submicron pores first. As the displacement pressure difference increases, oil production from large pores decreases, with medium pores becoming the main force of oil production, while oil production from nanoscale micropores shows an increasing trend. The increase in oxygen content results in significant development of sub-micron micron scale pores. The gas breakthrough time is long, the capillary force decreases, and air can undergo low-temperature oxidation with crude oil, resulting in an overall oil displacement efficiency of 65.81%. Novel/Additive Information: At present, there is few research on the pore fluid flow and status of oil displacement in tight conglomerate reservoirs with different injection media. This study provides a good understanding of the submicron to nanoscale pore throat structure characteristics of tight oil reservoirs, revealing the state of pore fluids in gravel after displacement by different injection media, and providing support for on-site application of CO2 enhanced oil recovery in tight conglomerate oil reservoirs.
Current Status and Trends in Shale Oil and Gas Drilling Engineering Technology Development at Home and Abroad
Authors: Jing Yu , Bo Zhou , Pingliang Fang , Bing Li , Wenchao Sun , Long Chang
Published: November 2024

Shale oil and gas is an important component of unconventional oil and gas, and the United States has achieved energy independence through the shale revolution. China has abundant unconventional oil and gas resources, and the vigorous development of shale oil and gas is a necessary path for the development of China’s oil and gas industry. By systematically analyzing the developmental characteristics of shale oil and gas major countries, represented by North America, this study compares domestic and foreign shale oil and gas drilling engineering technologies from the perspectives of development process, well construction cycle, drilling parameters, and other aspects. It clarifies the advantages and challenges of Chinese shale oil and gas drilling engineering technology and provides targeted recommendations. The drilling mode for shale oil and gas in China has progressed from single horizontal wells to large-scale platform factory operations, significantly reducing costs and increasing efficiency. However, due to the complex geological conditions of shale formations and poor surface environment, China’s shale oil and gas wells have a horizontal section length about 1000 meters shorter than those in North America, and the well construction cycle is 2-3 times longer. There are still certain gaps in drilling efficiency and operating costs compared to foreign countries. By systematically analyzing the development process and parameter characteristics of shale oil and gas drilling engineering technology at home and abroad, this study clarifies the current status of drilling engineering technology, providing references for the integration and promotion of mature technologies, demonstration of key core technology breakthroughs, and exploration of cutting-edge technology research and development.
Optimization of Welding Process for 825 Bimetallic Composite Pipes Based on Corrosion Testing
Authors: Fu Ling-di , Gao Jian , Li Chao-lang , Zhao Shuai
Published: November 2024

In the process of welding bimetallic composite pipe ring joints, a problem arises where the outer layer of carbon steel dilutes the inner corrosion-resistant alloy lining, resulting in a reduction in corrosion resistance. Therefore, selecting the appropriate welding process and parameters is crucial. This study established manual, semi-automatic, and fully automatic welding processes for welding 825 bimetallic composite pipes, conducted simulated corrosion tests on weld joint ring seams under sulfur-containing conditions, and performed comprehensive evaluations of physical and chemical properties, as well as corrosion resistance. The research findings are as follows: (1) There is a phenomenon of softening in the heat-affected zone of bimetallic composite pipe ring seams. Among them, the fully automatic welding method exhibits significant fluctuations in weld joint strength, higher toughness in the weld and heat-affected zone, and higher hardness values with less variation compared to other welding methods. (2) Under the manual, semi-automatic, and automatic welding processes, the intergranular corrosion rates are 1.08 mm/a, 1.64 mm/a, and 1.11 mm/a, respectively, and the pitting corrosion rates are 0.41 g/m2, 0.25 g/m2, and 0.31 g/m2, respectively. The uniform corrosion rates are 0.0002305 mm/a, 0.0002183 mm/a, and 0.0002197 mm/a, respectively. (3) High-temperature solution heat treatment (above 980 ° C for 30 minutes) can effectively promote the dissolution of carbides into the matrix, improving the intergranular corrosion resistance of alloy 825. The research demonstrates that under sulfur-containing conditions, weld joints obtained using the fully automatic welding process developed in this study exhibit better physical characteristics and corrosion resistance. This can effectively prevent corrosion failures and leakage incidents.
Main Challenges and Strategies to Develop Santos Basin Sub-Salt Fields, Deep water Brazil
Authors: Wang Yaqing , Gao Ce , Jiang Bin , Shang Fanjie
Published: November 2024

Santos basin of Brazil is a hot area of oil and gas exploration and development in the world. Many sub-salt oil fields have been discovered in recent years. The reservoirs are mainly composed of microbial carbonate rocks with strong heterogeneity, which has developed a variety of storage space types. The fluid is complex with high gas oil ratio and CO2 content. The re-injection of produced gas brings uncertainty to the production performance and the stability of facilities. The project investment is huge due to many factors such as deep-water, deep buried and far away from the coastline. The complexity of reservoir and high investment of project make the economic and effective development of reservoir full of great challenges. This paper describes the development strategies of Brazil’s sub-salt deep-water oilfield and the main successful methods to maximize recovery and profits under uncertain conditions. It includes the following three aspects: (1) abundant information acquisition to reduce the main uncertainties; (2) development plan with robustness and flexibility to deal with potential risks; (3) multidisciplinary comprehensive research to evaluate reservoir mode and development mode.