bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualization of the Characteristics of Polymer Gel Plugging of Fracture in the Multi-Slug Process
Authors: Wang Kai , Luo Ming-Liang , Li Ming-Zhong , Wu Bei-Bei , Fan Qiao 
Published: November 2024

Abstract
Polymer gel is a promising system for conformance control and water shutoff in water flooding reservoirs. However, the presence of fractures in reservoirs poses a major challenge to the successful application of polymer gels. This is because direct visualization of polymer gel system flow in the fracture is still lacking. In this paper, the HPAM/CrAc gel system was used to study the transport and plugging characteristics of gel multi-slug plugging using a visualized fracture model. The experimental results showed that multi-slug plugging accompanied by gradual compaction significantly improved the blocking strength of the polymer gel within the fracture. Specifically, multi-slug plugging improves the pressure gradient of the chasing water by approximately 80-200 kPa/m compared to one-step plugging of the polymer gel. During multi-slug plugging of the fracture, the later injected gelant slugs pass through the weak areas of the prior matured gel slugs and continue to move behind them instead of pushing the prior matured gel as a whole to the distal portion of the fracture. After the polymer gel one-step plugging of the fracture, chasing water will pass through the edges of the fracture where the gel is not adequately filled or directly through the mature gel in the form of wormholes. In contrast, after multi-slug plugging of the fracture, the mature gel is not easy to be breached by chasing water because of the compaction effect, while the junction between the mature gels of each slug will become an easy area for chasing water to break through. But it is still more difficult to break through than the one-step plugging process. This research is informative for the improvement of polymer gel systems and their successful application in fractured reservoirs for conformance control and water shutoff.
Integrated Permeability Stress Sensitivity Studies of Multi-cycle Injection and Production for Underground Gas Storage
Authors: Zhang Lingfeng , Tang Kang , Shangguan Yangnan , Liao Xinwei , Zhang Wugang 
Published: November 2024

Abstract
This paper details the design of multi-cycle injection and production stress simulation experiments, aimed at quantitatively characterizing the permeability stress sensitivity in underground gas storage(UGS) during multiple operation cycles. Derived from the reservoir sensitivity evaluation method and the stress sensitivity coefficient method, a suite of stress sensitivity evaluation index was introduced to discuss the effect of stress variation paths on the stress sensitivity characteristics. It is found out that the stress sensitivity is common in sampled gas storage cores. Meanwhile, there is a significant stress sensitivity hysteresis effect in multi-cycle injection and withdrawal experiments. After multiple cycles, the rock stress sensitivity is less dependent on the stress path. However, due to the superposition of multiple cycle stress sensitive hysteresis effect, the multi-cycle permeability damage ratio and irreversible damage ratio increased. The phenomenon of stress sensitivity hysteresis is especially pronounced in cores with low permeability. This study offers a theoretical foundation for predicting gas storage operation schemes and formulating technical policies.
Mechanism of Minerals Action in Reservoir During CCS
Authors: Zhao Xin , Wu Baofeng , Yan Liping , Li Chenglong , Duan Yajie , Wang Xin 
Published: November 2024

Abstract
The carbon capture and storage (CCS) is one of the most effective ways to control greenhouse gases emissions and mitigate greenhouse effects. There will be a series of effects on the physical properties and chemical composition of the reservoir after CO2 injection. It is of great significance to study the effect of CO2 injection on reservoir for better CO2 storage. In this paper, Through the mechanism model established by numerical simulation technology and the phase permeability hysteresis simulation method, the whole process of reservoir pH, mineral dissolution and precipitation and porosity change during CO2 storage was accurately described. The results indicate that CO2 firstly dissolves in water to form carbonic acid after injection into the reservoir, which will cause a drastic change acid-base properties of reservoir, manifesting as a significant decrease in pH value. Under the effect of H
+, Partia mineral components(for example: anorthite) in the reservoir) are dissolved, however, some other minerals (for example: kaolinite and calcite) are precipitated, which significantly change the composition of underground aqueous solution. The reaction rate of CO2-water-rock is very slow. After stopping CO2 injection, the mineralization of all kinds of minerals still goes on for a long time. In addition, due to the effect of CO2-water-rock reaction, a certain increase of reservoir porosity is more conducive to CO2 migration in the reservoir.
The influence of multi-scale fractures on 3D geological modeling of carbonate reservoir: An application case analysis of Anyue Gas Field
Authors: Chen Weihua , Yang Miao , Wang Xi , Yang Xing , Li Xucheng , Luo Le 
Published: November 2024

Abstract
The carbonate reservoirs of the Dengying Formation in the Sinian system are well-developed, but with strong heterogeneity and natural fractures. Conducting three-dimensional fracture modeling research has important guiding significance for deepening the geological understanding and development plan formulation of this gas field. This paper starts from three-dimensional high-precision seismic data, distinguishes cracks of different scales, and uses deep learning technology and Aberrance detection technology to carry out multi-scale crack prediction of the target layer in the research area. Based on this, high-precision crack modeling work is carried out. The on-site construction results show that the natural crack model established by this technology series has high accuracy and has promotional application value in the next step of improving gas field development efficiency.
Study on the Influence of Structural Parameters of Microwave Heating Device on the Heating Effect of Natural Gas Hydrate Reservoir
Authors: Fan Shen , Wang Han-Xiang , Zhang Xin , Sun Bing-Yu , Ge Jia-Wang , Lv Yu-Bin , Chen Xu-Hui , Meng Xiang , Zhang Heng 
Published: November 2024

Abstract
The investigation into microwave heating technology for enhancing gas production from hydrate reservoir has attracted wide attention. However, the initial microwave heating device structure still has limitations of low average temperature and uneven temperature distribution in the reservoir during microwave heating. This study has established the microwave heating simulation model, which is validated by the reservoir microwave heating experiment results. Based on the simulation results of microwave heating model, the optimized structure parameters of microwave heating device are obtained: the slots distribution method is cross-distribution, the slot shape is rectangle, the slot angle is 75°, and the slot length is 30 mm. Following microwave heating with the optimized structure for 10 hours, the average temperature within the 1-meter radius of the reservoir rises from 2 °C to 9.52 °C, the maximum temperature in the reservoir is 58.21 °C, and the temperature standard deviation is 9.15 °C. The results mentioned above indicate that the optimized structure can well increase the temperature in the gas hydrate reservoir and the temperature distribution is uniform. This study will further promote the application of microwave heating technology in the actual exploitation of natural gas hydrate.
Research on Automatic Pipe Cleaning Technology for Natural Gas Medium and Low Pressure Pipelines
Authors: Liu Xin-Yu , Yang Jian-Dong , Zhang Yun , Zhang Xiang-Jing , Liu Huan-Yu , Duan Xin-Hai 
Published: November 2024

Abstract
As the number of low-production and low-efficiency wells in Chang Qing gas field increases gradually, and the problems of pipeline liquid accumulation, freezing plugging and leakage due to production with liquid are worsening, in view of the low efficiency of manual analysis of abnormal pipeline status, the difficulty of timely detection of potential problems and the labor intensity of manual blockage clearing operation, we study an automatic pipeline clearing technology applicable to medium- and low-pressure gas pipelines in the gas field, which mainly includes pipeline operation status analysis and early warning system and automatic pipeline clearing device. An analysis and warning algorithm module is proposed to analyze, warn and locate the frozen plugging point based on pipeline pressure, differential pressure and flow parameters in real time. A low and medium pressure balling device is designed to achieve the goals of intelligent control, pressure isolation balling and safe operation through mechanical structure design, automatic control system and safety protection system. The device and system are applied in the well field at the end of 1 and 3# trunk pipelines of Shen Mu Gas Field Station 7, which verifies the feasibility, accuracy and stability of the technology. Based on the joint operation of the pipeline analysis and warning system and the automatic pipeline clearing device, it is able to meet the remote intelligent pipeline clearing operation and pipeline maintenance tasks in the process of gas gathering and transmission in the gas field.
Analysis of classification results of rock cores with different physical properties based on clustering algorithm
Authors: Guo Qi 
Published: November 2024

Abstract
In response to the problem of high difficulty in development caused by different physical properties differences during water flooding in high water bearing oil fields, effective flow unit division and analysis were carried out in Zone 1 of Gangxi through flow unit analysis. The physical property classification of each rock core in the flow unit was determined using the GMM cluster algorithm. The results show that Class I flow units have high permeability and porosity, and good pore permeability performance; The porosity and permeability distribution range of Class II flow units is the widest, with some pore permeability performance comparable to or even higher than Class I, and overall pore permeability performance is good; The porosity and permeability of Class III flow units are lower than the first two types, and their pore permeability performance is relatively poor. The types of core porosity and permeability in the study area can be divided into four categories, with the majority being high permeability, ultra-high permeability, and high permeability. The new research results provide a reference basis for the study of physical property distribution and later well network deployment in the first block of Gangxi District.
Research and Application of Leakage Monitoring Techniques for Gas Field Water Pipelines
Authors: Zhong Xue , Zhang Wen-Yan , Liu Yu-Hao , Qi Jia-Yi , Gu Tao 
Published: November 2024

Abstract
To study the effectiveness and application effects of leakage monitoring techniques for gas field water pipelines in the Sichuan-Chongqing region, seven kinds of flow limitation holes with different diameters were used to simulate the leakage of the gas field water pipeline to carry out a field test. The monitoring conditions of two leakage monitoring techniques, namely dynamic pressure wave compound method and negative pressure wave and transmission balance method, were compared and analyzed under different working conditions. The test results showed that: (1) When the pipeline was full, the leakage with apertures being smaller than 2 mm could not be effectively monitored. A single-end alarm could be achieved using the dynamic pressure wave compound method, but the positioning was ineffective. An alarm could not be effectively achieved using the transmission balance method. (2) When the pipeline was full, for the leakage with apertures being 2 mm and above, early warning could be well achieved using the both methods, and the monitoring effects were nearly the same, with the average positioning error being about 48 m and the average alarm response time being about 58 s. (3) When there were empty pipe slug flows in the pipeline, only apertures being 5 mm and above could be alarmed; however, positioning could not be effectively achieved, and system technical indicators could not be reached. (4) When there were large elevation differences in the gas field water pipeline and empty pipe slug flows could not be eliminated, the both techniques were not applicable.
Caprock Safety Evaluation Method in CCUS Based on Latin Hypercube Sampling: A case study of a block reservoir
Authors: Hou Shan-ze , Liao Xin-wei , Wang Xiao-chen , Zhang Ling-feng , Chen Zhi-ping 
Published: November 2024

Abstract
CO2 geological sequestration is one of the essential means to achieve carbon neutrality goals. However, substantial CO2 sequestration in formations can lead to leakage issues, primarily through the caprock, involving caprock rupture, leakage along caprock fractures/faults, and capillary leakage. Therefore, establishing a method to assess the safety of the caprock during CO2 storage processes is crucial. Firstly, a numerical simulation model is constructed based on parameters from the target block to study the influences of reservoir property, development parameters, and caprock parameters on CO2 flooding, gas injection, and CO2 storage. Latin hypercube sampling is employed for scheme design and subsequent result analysis, applying Spearman’s method to analyze the controlling factors in each CO2 storage. Secondly, using continuous gas flooding as an example, the migration pattern of CO2 in the formation is investigated, and the influence of the formation pressure distribution on caprock safety is analyzed. Finally, considering the comprehensive impact of different parameters on caprock safety, a fuzzy comprehensive evaluation of caprock safety in the target block is conducted. The study indicates that caprock permeability is the most critical factor affecting safety operation across all storage stages, with respective highest positive correlation coefficients of 0.413, 0.356, and 0.221 in different stages. The migration of CO2 in the formation is primarily influenced by the distribution of injection wells and gas migration channels. The established quantitative evaluation standard for caprock safety in the target block calculates a suitability degree of 3.43, suggesting a relatively secure caprock in the block suitable for achieving long-term stable CO2 storage. This research provides theoretical support for the safety analysis of caprock in different stages of CO2 flooding and storage, offering a scientific basis for the safety operation of CCUS schemes.
Research on DFN Fracture Modeling and Fracturing Network Expansion Simulation Method for Shale Reservoirs
Authors: Yong Jie , Ge Li , Qin Li , Sun Jian , Liu Fei , Liu Kaiyuan 
Published: November 2024

Abstract
The degree of natural fracture formation and their link to hydraulic fracturing fractures are critical factors in production in the current large-scale fracturing development of shale gas reservoirs. Any magnitude of fractured reservoir heterogeneity may be described using the Discrete Fracture Network (DFN) model. This paper builds on earlier research by providing an additional summary of the multiscale DFN fracture modeling method, analyzing the fracture occurrence using statistical analysis techniques, analyzing the fracture scale using fractal theory, and determining the fracture development degree by combining the fracture attributes in imaging logging and three-dimensional seismic data. Different-scale fracture network models were developed. Simulating the growth of hydraulic fractures accurately using Mohr Coulomb and Barton Bandis criteria, this study also takes into account the interaction between natural and hydraulic fractures, as well as the physical properties of the rock (e.g., elastic modulus, Poisson’s ratio), closure pressure, crustal stress field, and other factors. The fracture network information, sitmulated reservoir volume, stress shadow and other attributes obtained from fracturing simulation can further analyze and evaluate the effect of fracturing simulation, and optimize the well location deployment plan and construction plan in combination with geological engineering conditions.
Field Application of Evaluation Model for Development Effect on Horizontal Waterflooding in Thin Low-permeability Carbonate Reservoirs
Authors: Hu Dandan , Wu Yuanbing , Zhang Haikuan , Ma Ruicheng , Li Qianyao , Hu Songhao , Chen Yihang 
Published: November 2024

Abstract
Low-permeability carbonate reservoirs with layered characteristics generally exist in Middle East district. The reservoirs achieved low recovery efficiency using vertical well by depletion mode in the early stage, and low horizontal and vertical sweep efficiency by vertical waterflooding due to high permeability streak and interlayer. Some oilfields in the district has successively implemented horizontal waterflooding technology and achieved good development results. Feasible and effective report has not been provided yet on the problem that the range of recoverable reserves and recovery efficiency can be increased by horizontal waterflooding. Considering some oilfields accomplished horizontal waterflooding in quick succession and some oilfields were just developed by horizontal waterflooding, practical resolution should be recommended such as the corresponding evaluation model for enhancing recovery efficiency range of the technology. The paper put forward an evaluation model for enhancing recovery reserves and recovery efficiency of horizontal waterflooding based on production decline model and waterflooding curve model. The resolution can also provide an evaluation basis of enhancing recovery efficiency for optimization and adjustment of horizontal water flooding. Applications of these concepts are illustrated with D oilfield in Oman. Results indicated that recovery efficiency by horizontal waterflooding after natural depletion development may be increased around 25% and about 4% by the optimization and adjustment process. The evaluation model will be used effectively to predict IOR effect of the similar reservoirs in Middle East oilfields.
Effects of pH on Polyacrylamide Polymers in Chemical Degradation: A Review
Authors: Liu Kexin , Liu Pingli , Du Juan 
Published: November 2024

Abstract
Chemicals, such as strong oxidant and acid, are generally used for removing the polymer (mainly polyacrylamide polymer) damage in polymer injection wells. The strong oxidant degrades the polymer by breaking polymer molecular chain, but the mechanism of polymer degradation by acid or pH has not been fully studied. Therefore, the previous studies on the effect of pH value on polymers are reviewed in this paper, and the basic principle of oxidative degradation of polymers, the effect of pH on polymer production, and the principle of viscosity reduction of polymers caused by acid solution are emphatically described. A large number of studies have found that the principle of oxidative degradation of polymers is the fracture of polymer molecular chains, and the reduction of polymer viscosity by acid solution does not cause the polymer molecular chains to break, but only makes the polymer molecular chains tightly wound and shrink. The results showed that the effect of pH on polymer viscosity is reversible. The acid solution makes the polymer molecular chain tightly wound and contract by reducing the pH value of the polymer solution, reducing the viscosity of the solution, but the polymer chains are not broken, and by increasing the pH value of the polymer solution through the alkali solution, the viscosity of the solution can be increased, and even the polymer molecular chain can be restored to the original state. So, the oxidant is still essential to degrade polymers. It is unreasonable to evaluate the degradation effect of polymer only based on the change of polymer viscosity. Various factors such as molecular weight and molecular structure should be considered comprehensively through various detection methods. Through the research and discussion of this problem, the relevant experimental research of polymer degradation can be further improved, which provides some new ideas for the research of plugging removal and injection increase in oil Wells, and lays a foundation for plugging removal technology and technology in oil Wells.
Possibilities For Using Ionic Liquids In The Polymerization Process
Authors: Pashayeva Ziyarat Naghi , İBragimova Minavar Jafar , Abdullayeva Fakhriyya Mohammad 
Published: November 2024

Abstract
The paper investigates the polymerization of various methacrylate esters in different ionic liquids (ILs) and compares the results with those obtained in traditional organic solvents, particularly benzene. The study highlights the influence of ILs on the polymerization process, focusing on factors such as polymer yield, average molecular weight, and thermal stability. The results indicate a relatively higher degree of polymerization in ILs compared to benzene under identical conditions. Additionally, polymers synthesized in ILs exhibit higher average molecular weights and thermal stability. The observed differences are attributed to the unique properties of ILs, such as low chain transfer rate constants and the ability to stabilize active radicals during polymerization. The findings underscore the potential of ILs as promising reaction media for polymer synthesis, offering improved efficiency and polymer properties compared to conventional organic solvents.
Development of GIS-based framework for reservoir data management and quality evaluation
Authors: Yi Ziliang , Yao Jun 
Published: November 2024

Abstract
Accurately measuring and understanding reservoirs is critical for ensuring successful reservoir development, reservoir development evaluation have become an increasingly important issue in reservoir development engineering and present many challenges, particularly when attempting to integrate and visualize multiple types of data. This paper presents the methodologies, techniques and integrated services adopted for the design and implementation of A quantitative oil and gas reservoir data management and evaluation system. The system is an integrated application based on petroleum geology and GIS technology for managing, displaying, administering and analyzing petroleum geological data. In addition, the system is capable of evaluating reservoir quality and input data quality which provides effective recommendations for the design and preparation of reservoir development programs. In this study, a GIS-based quantitative evaluation module was developed considering both reservoir and input data quality. In this case, the reservoir quality index is determined by five major elements, and the input data quality is determined by the quality of six data sources. The weights of each element are determined by principal component analysis (PCA). Developed a raw data output processing software in C# using ArcGIS engine functions, which automatically generates visual maps and reservoir quality assessment information. The feasibility of the platform is verified by using the geological data of Linfen gas field Formation in the eastern slope of Shanxi. The integrated framework system proposed in this study enables decision-makers and the publics to quickly response to oil reservoir development events and allows an easy adaptation to other regional and scientific domains related to real-time monitoring and evaluating.