bluuebunny/crossref_metadata_2025_split 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.