bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method of Using Production Data to Predict the Effect of Oil Well Liquid Lifting Based on Deep Learning
Authors: Lu Shuiqingshan , Cui Chuanzhi , Wu Zhongwei , Qian Yin , He Jiajie 
Published: November 2024

Abstract
Liquid lifting is a low-cost, straightforward, and efficient measure for stabilizing production, achieved by adjusting liquid production to reduce bottom-hole flow pressure, thereby optimizing reservoir development and increasing recovery rates. However, traditional research methods for liquid lifting no longer meet the demands of contemporary oilfield big data applications. Particularly in the selection of target wells for liquid lifting, manual screening based on chart methods faces challenges such as low efficiency, high workload, and poor generalization capabilities. This study focuses on the oil wells in the high water cut phase of the SL oilfield in China and proposes a novel data-driven approach to predict the liquid lifting effects of oil wells. This method forecasts the effect of liquid lifting measures based on dynamic and static production data before the implementation of liquid lifting measures, facilitating intelligent selection of oil wells for liquid lifting measures. Firstly, each evaluation metric is assigned weights by utilizing the Coefficient of Variation-G1 Hybrid Cross-Weighting method. The comprehensive evaluation score is obtained through a weighted sum. Subsequently, the self-organizing map (SOM) clustering method is applied to categorize the oil well liquid lifting effects into four classes (A, B, C, D), representing different levels of effect. Additionally, a learning sample dataset is constructed by selecting multidimensional time-series features before liquid lifting. The oil well liquid lifting effect classification model is established using the Bi-LSTM sequence-to-label deep learning algorithm. Comprehensive testing validates the superior performance of the model, especially with classification accuracies of 0.96 and 0.83 on the training and testing sets, respectively. These results outperform other classification models such as LSTM, XGBoost, and SVM, providing an effective tool for intelligent oil well selection in liquid lifting measures.
Research on Numerical Simulation Methods for Water Invasion Dynamics in Fractured Gas Reservoirs with Water Content
Authors: Ruan Jifu , Yi Jin , Li Xinling , Chen Chunyan , Li Xianghong 
Published: November 2024

Abstract
Fractured gas reservoirs with water have complex gas-water relationship, large permeability difference between matrix and fracture, complex gas-water percolation mode, rapid production decline, short stable production period and large reduction of recovery factor due to water production of gas wells, which poses great challenges to efficient development of gas fields. The fracture system is the main channel for the edge and bottom water channeling of gas reservoirs. It is the core issue to understand the water invasion dynamic characteristics of such gas reservoirs to accurately depict the fracture geometry occurrence and truly simulate the gas-water two-phase flow mechanism in the fracture-matrix dual media. Taking the Jia-2 gas reservoir in Moxi gas field as an example, a discrete fracture model construction method that explicitly characterizes the fracture system is proposed. Based on the discrete fracture model, a mathematical model of gas-water two-phase flow in the fracture-matrix dual system is constructed and numerically solved. The influence mechanism of fracture opening, length, density and occurrence on the water invasion performance of multi-layer gas reservoirs is discussed, and the main control factors of the water invasion and water channeling law of fractured water gas reservoirs are identified. The application shows that the water invasion dynamics of gas reservoirs based on the discrete fracture model are more consistent with the actual conditions of the mine, providing a theoretical basis for deepening the understanding of water invasion dynamics of this type of gas reservoirs, optimizing the gas well working system, and formulating targeted water control countermeasures..
Development and Application of a Chelating Acid for Water Injection Wells of Chang 6 Reservoir of An-Sai Oilfield
Authors: Wan Xiang-hui , Zheng Wei-shi , Jiang Wen-xue , Chen Ying-hua , Li Yong , Zhang Bin 
Published: November 2024

Abstract
Ansai oilfield is a typical low permeability, low pressure, low yield and serious heterogeneity oilfield. Chang 6 play of Triassic YanChang Formation is a typical ultra-low permeability reservoir. The average porosity of the reservoir is 10 % ~ 14 %, and the average permeability is (0.2 ~ 4.0) × 10−3 μm2. The absolute content of clay minerals in the reservoir is relatively high, with an average content of 18.61 %. The main components are kaolinite, chlorite, illite and illite/montmorillonite interlayer. Due to the reservoir blockage caused by scaling, water sensitivity and formation particle migration in the process of water injection, high injection pressure and under injection wells is increasing dramatically. In view of the above challenges, a fit-for-purpose acid, which contains organic acids and chelating agents, was developed for injection pressure reduction and injection enhancement. It has the characteristics of strong dissolution, good retarding and corrosion inhibition performance. Corrosion rate is 0.5632 g / (m2·h) for J55 steel in 24h, and the core permeability increases by 74.57 % after acid flooding. It has been applied in field test of 3 wells in Chang 6 layer of Ansai oilfield since March 2024. The average daily injection volume increased by 37.87 %, and the validity period was more than 180 days.
Effect of Solid Particles in Polymer Waste Liquid on Grinding Tool Wall Erosion
Authors: Bingyu Sun , Hanxiang Wang , Shen Fan , Jingwen Ren , Yi Yuan , Yuting Wang 
Published: November 2024

Abstract
With the continuous accumulation of polymer waste liquid in the third oil recovery process, the treatment of wellhead return waste liquid has become a key issue in oilfield exploitation and environmental protection. In this paper, the erosion failure of the cutter caused by sand-containing particles in the waste liquid during the shear grinding process is studied. The influence of the main structural parameters of the grinding tool and the erosion failure is studied by using the comprehensive numerical simulation method to reduce the erosion rate of the polymer flooding waste liquid on the cutter. Firstly, the flow field model of the solid-liquid fluid is established, and the erosion phenomenon on the tool wall is studied by combining the model with field experiments. In addition, the relationship between the different cutters structure and erosion rate of the grinding tool is studied, and the mathematical model is established. The optimized structural parameters are given to enhance the erosion resistance of the grinding tool in the process of polymer flooding wellhead waste liquid treatment and prolong its service life.
Research and Application of Intelligent Well Completion Technology in Offshore Oilfield
Authors: Zhang Qilong , Li Zhong , Weng Haoyang , Liu Wei , Huang Zhongwei , Zhang Bin 
Published: November 2024

Abstract
The reservoirs in Bohai oilfield were mainly composed of unconsolidated sandstone. A single multi-layer gravel packing operation could greatly reduce the packing operation time and improve the operation efficiency. However, the conventional tools were limited by the double-layer central tube structure, which resulted in large packing friction and high pressure consumption due to its small annular area, which limited the limit operation length and displacement. In order to solve this problem, we independently developed a double-layer screen tube one-time multi-layer fracturing packing tool, innovatively set up production interlayer in the screen pipe, formed a bypass diversion screen pipe system, so as to reduce the downward entry of one layer of central pipe during filling, simplify the structure of the filling string, and greatly reduce the friction of the string. The results showed that the limit packing length and displacement were 1200m and 45bpm respectively, which were 300% and 50% higher than the traditional packing tools, and the operation range of the tools was improved. The safety and efficiency of double screen fracturing and filling operation were ensured by innovating the quick connection method of double screen pipe, fast pressure test tool and expanding switch tool of oil pipe. The application in well LX has realized the purpose of sand control by five layers filling in one time. The packing length was more than 400 m. Combined with the problems in field operation, it had been applied in 5 areas The improvement suggestions of the tool are put forward. The double screen pipe one-time multi-layer fracturing packing tool and its supporting technology realized the ideal packing parameter requirements of low pump pressure and high return velocity. It could be widely used in sand control operation of multi-layer gravel packing fracturing in large-span perforation section in the future, which greatly improved the operation efficiency and has good economic benefits and promotion value.
Favorable Diagenesis and Pore Evolution of The Qi-2 Member Reservoir in the Hechuan-Tongnan Area
Authors: Liu Yunmiao 
Published: November 2024

Abstract
This article takes the Qi-2 member dolomite reservoir in the Hechuan-Tongnan area as the research object, and combines research methods such as drilling cores, thin section analysis, CT scanning, and geochemical analysis to deeply explore the pore structure characteristics, diagenetic characteristics, and influencing factors on pore evolution of the Qi-2 member dolomite reservoir. This results indicate that: ①The Qi-2 member should develop two types of reservoir spaces: pores and fractures. The reservoir space is mainly composed of intercrystalline dissolved pores (0.5∼5%), dissolved fractures and dissolved cavities (2∼4%). The intercrystalline pores are relatively evenly distributed, and the fractures improve the connectivity of pores. The reservoir space of the poor gas layer is mainly composed of biocast pores and intragranular dissolved pores (1∼2%), which are relatively isolated; ② The matrix pores of the Qi-2 member are relatively evenly distributed, with a radius of 200μm~600μm is the main focus. The throat radius is mainly 20μm~60μm fine throats.③According to the effect of diagenesis on pore evolution of dolomite reservoir in Qi-2 formation, it can be divided into constructive and destructive. The formation of reservoir space is mainly caused by quasi-syngenetic atmospheric fresh water erosion, and the matrix pores are mainly intercrystalline pores and intercrystalline dissolved pores. The early dolomitization is the key factor of pore preservation. The geological study of dolomite reservoir of the Qixia Formation in the Daqing exploration area has been enhanced, providing strong basis for reservoir prediction and deployment in the later stage.
A Study on the Paleoclimate and Sedimentary Environment of the Upper Kuli Formation in the Hailar Basin
Authors: Tian Yu , Xue Yunfei , Liu Yunmiao , Liu Ming , Bu Chunyang , Gong Xuenan 
Published: November 2024

Abstract
The Kuli Formation in the Hailar Basin has a wide distribution range, complex and variable lithology, and oil and gas indications during field investigations, which has great research significance and value. In order to better understand the paleoclimate and sedimentary environment of the Upper Kuli Formation, this article uses three methods for the first time: heavy mineral analysis, sporopollen fossils identification, and inorganic element analysis. Based on the characteristics of heavy mineral assemblages, sporopollen fossils identification, and element analysis correspond to the five bottom layer combinations of heavy mineral analysis, analyzing their respective combination characteristics and change patterns. With a more comprehensive perspective and higher time resolution, Cross validation improves the accuracy and credibility of its inference. The results indicate that the Upper Kuli Formation can be divided into five combinations from bottom to top. The paleoclimate underwent a transition from a humid environment to a drier environment. The sedimentary environment has undergone a transition from a deep-water environment to a shallow water environment, transitioning from dynamic, rapid sedimentation, and strong terrestrial influences to a sedimentary environment dominated by more static water, chemical precipitation, and diagenesis. This study combines different geological and geochemical analysis methods to provide strong basis for inferring the paleoclimate and sedimentary environment of the Upper Kuli Formation. The research results are of great significance for interpreting geological changes such as paleoclimate change and ecosystem evolution.
Analysis of Corrosion Causes and Optimization of Corrosion Evaluation Methods for Water Injection System in Changqing JY Oilfield
Authors: Zhijie Hu , Jinliang Du , ying Si Yang , Xiaoling Wang , Huan Li 
Published: November 2024

Abstract
Based on the corrosion characteristics of the water injection system in Changqing Oilfield, an experimental study was conducted on the corrosion of the water injection system caused by carbon dioxide, hydrogen sulfide, bacteria, and water treatment agents in the produced liquid. The main influencing factors of corrosion in the water injection system were analyzed, and it was clarified that the corrosion of the water injection system in Changqing Oilfield was mainly caused by oxygen corrosion, which also had an impact on the water quality of the injection. Combining static corrosion analysis with the introduction of pitting and dynamic corrosion rate testing methods, the average corrosion rate of JY oilfield water injection system has a positive correlation with pitting corrosion, while the average corrosion rate of clean water has a stronger correlation with pitting corrosion. The corrosion evaluation method has been optimized, providing technical basis for formulating effective anti-corrosion measures for the oilfield.
Reliability Analysis of Subsea Riser System Based on Fuzzy Fault Tree Analysis Method
Authors: Zhou Chuankun , Liu Jian , Yu Xiaolong , Jiao Zihao , Zhang Guangfei , Liu Chao , Chen Yaqi 
Published: November 2024

Abstract
To deal with the complex structure of subsea riser system and the lack of failure statistics and insufficient information during operation, a fuzzy fault tree analysis (FFTA) method is applied to analyse the reliability of the subsea riser system, and a qualitative and quantitative analysis is carried out by establishing a fault tree model of the riser system to obtain the minimum set of cuts and the basic events. The fuzzy importance degree of each fundamental event is determined as well as the failure probability of the headline event of the fuzzy fault tree, “failure of subsea riser system,” using the triangular fuzzy number computation method. Finally, the “average value” method of comprehensive analysis of the fault tree model, the analysis results show that the bottom event riser check valve, riser buoyancy device, riser working medium isolation valve, riser line, riser gas lift device and other components of the failure of the subsea riser system is relatively the weak links, compared with the actual situation, the analysis results in line with the actual engineering situation, these five aspects should be regularly detected and focused on prevention. In conclusion, this research helps to comprehensively analyse the reliability of the riser system and take into account the uncertainty factors, and provides more accurate guidance on the reliability constraints for the localized design and production of subsea riser system.
The Flowback Proppant Scaling Mechanism in the Horizontal Shale Oil Wells of Qingcheng Oilfield
Authors: Yang Le , Li Qiongwei , Li Kai , Yuan Huiying , Qi Yin , Mu Lijun , Yang LiHua , Guo Gang , Wang Weijun 
Published: November 2024

Abstract
Proppant scaling in the horizontal shale oil wells is a common problem in the Qingcheng Oilfield, one of the largest shale oil producers in China. However, few studies have focused on the mechanism of the proppant scaling during the flowback stage of hydraulic fracturing. To elucidate the scaling mechanism, in this study we collected the samples of produced water and solid scales and analyzed their compositions. The experimental simulations of the static and dynamic scaling processes using fracturing fluids, formation water, and reservoir rocks were also performed.
In these experiments, the scale was found to be mainly SiO2 combined with FeCO3 and/or CaCO3. FeCO3 was dominant at the initial stage of the flowback, and CaCO3 became dominant at later stages of the flowback and during the stable production stage. It is believed that the high percentage of ferrous minerals (e.g., 46.4% of ferrocalcite) in multiple formation rocks is an essential reason that the proppant scaling happened during the flowback stage. The Fe2+ and Ca2+ ions were believed to be released via reservoir rock reacting with the fracturing fluid under the reservoir temperature and pressure (e.g. 60 °C, 20MPa). In addition, the FeCO3 formed in the initial flowback stage of the fracturing has the greatest impact on production.
Research and Application of Drilling and Completion Technology for Cluster Wells
Authors: Jiang Peng , Li Lihua , Fu Yueying 
Published: November 2024

Abstract
Huabei Oilfield has a wide range of oil and gas resources. With the pressure of environmental protection and the need for high-quality and cost-effective exploration and development, cluster drilling has also put forward higher requirements. In this oilfield, there is no effective technology in large cluster reservoir, integrated design of drilling and production, surface engineering, intensive construction, recycling of drilling fluid and so on. Taking a block in Bayan as the research focus, combined with geological characteristics, and by means of experiment and theoretical analysis, this paper focuses on the optimization of wellhead layout, trajectory optimization and drilling fluid recycling technology of cluster well, and forms the cluster well drilling and completion technology that is suitable for reservoir characteristics in the target area of Huabei Oilfield, so as to achieve the purpose of reducing cost and increasing efficiency, speeding up production and construction and expanding space.
Experimental Study on Oil-Gas Interface Stability Mechanism and Control Method of Gas-Assisted Gravity Drainage
Authors: Chen Xiaolong 
Published: November 2024

Abstract
The stability of oil-gas interface is an important factor affecting the recovery of the gas-assisted gravity drainage (GAGD). In this paper, the interface morphology characteristics of GAGD in porous media under 8 flow rates and 3 displacement dip angles were studied by using a visual physical model. The non-dimensional parameters such as capillary number and bond number were introduced to qualitatively characterize the oil gas interface morphology, and the process of gas invading the pore throat of porous media under different interface morphologies was revealed. The fractal dimension is employed for quantitative characterization of the morphology of the oil gas interface during the GAGD process, and the boundary of stable interface and unstable interface was divided. The study showed that the balance effect of gravity on the competition between capillary force and viscous force was the main reason for the stability of GAGD flooding leading edge. The stability of the oil-gas interface can be ensured by controlling the bond number to be greater than 2.75×10−4 and the capillary number to be less than 2.48×10−3. With a constant bond number, an increase in the capillary number leads to a gradual transition of the oil-gas interface from stable to unstable. Similarly, with a constant capillary number, an increase in the bond number causes the oil-gas interface to shift from stable to unstable. The fractal dimension divides the boundary between stable and non-stable displacement. When Df is greater than 1.87, the oil interface is stable, when Df is less than 1.75, the oil interface is viscous fingering, and when Df is between 1.75 and 1.87, the oil interface is mainly capillary fingering.
Mechanism recognition and application effect analysis of air injection development in ultra-low permeability oil reservoirs
Authors: Xin Liu 
Published: November 2024

Abstract
There are few application examples of air drive development technology in ultra-low permeability oil reservoirs in China. The article relies on the air drive development block of H oilfield, and based on the results of core start-up pressure gradient experiment, relative permeability experiment, gas composition experiment, and gas swelling experiment, conducts research and analysis on the seepage mechanism and low-temperature oxidation mechanism of air drive development, demonstrating the advantages of air drive development in oil displacement mechanism of ultra-low permeability oilfield. Based on the basic parameters of oil fields developed by air flooding both domestically and internationally, the specific blocks suitable for air flooding development in H oilfield are selected. The feasibility of conducting air flooding development in low permeability oil fields is demonstrated from three aspects: indoor real core experimental data, safety, and the maturity of existing equipment and technology. At the same time, an analysis is conducted on the development status of the air drive block in H oilfield. By comparing the development effects with adjacent water injection blocks, it is demonstrated that the air drive development effect in ultra-low permeability oilfield is superior to water injection development.
Study on the Multiphase Flow Behavior in the Jet Pump Lifted Natural Gas Hydrate Wells with Combined Depressurization and Heat Injection Method
Authors: Ping Xiaolin , Han Guoqing , Zhang Jiqun , Wang Hongliang , Liu Changchun , Liu Jungang 
Published: November 2024

Abstract
Natural gas hydrate production tests have been carried out successfully with different exploitation methods and gas recovery drainage technologies. The purpose of this study is to elucidate the fluid flow behavior in the jet pump lifted natural gas hydrate wells and optimize hot water injection parameters for the jet pump drainage gas recovery technology. The mechanism of jet pump drainage recovery of natural gas hydrate wells was analyzed and its applicability to natural gas hydrate exploitation with combined depressurization and heat injection method was demonstrated. In addition, multiphase flow models of tubing and annulus were established respectively for the phenomenon of countercurrent flow of heat exchange in the jet pump drainage gas recovery process, and the corresponding multiphase flow laws were derived. Based on the study of multiphase flow, sensitivity analysis and optimization of heat injection parameters were performed. It has been demonstrated that jet pump drainage gas recovery technology is suitable for the exploitation of onshore natural gas hydrate with combined depressurization and heat injection method. The multihphase flow behavior in the tubing and annulus of the jet pump lifted natural gas hydrate wells was disclosed in this study. Numerical simulation results show that the temperature and pressure distribution in the wellbore of the jet pump lifted natural gas hydrate wells during the recovery process are affected by the injection conditions. This study provides theoretical guidance for the production optimization and hydrate prevention and control in the wellbore of the jet pump lifted natural gas hydrate wells.