Geoenergy Science and Engineering最新文献

Mechanism of microfracture propagation under mechanical–chemical coupling conditions considering dissolution 考虑溶蚀的力学-化学耦合条件下微断裂扩展机制

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-28 DOI: 10.1016/j.geoen.2024.213544

Yan Zhuang , Tiantian Zhang , Xiangjun Liu , Shifeng Zhang , Lixi Liang , Jian Xiong , Xiaojian Zhang

Microfracture propagation is well known to significantly impact the stability of well bores in shale formations; however, there is a lack of research on the role of dissolution. Herein, a shale microfracture propagation model is constructed that couples mechanics and chemistry by considering hydration, capillary, strength weakening, and dissolution effects. Combining relevant experiments with the model reveals the mechanism of microfracture propagation. Results indicate that ΔK(stress intensity factor) shows an upward trend with increasing hydration micromechanical forces and when hydration time exceeds 30 h, the rate of increase in ΔK gradually slows down. ΔK increases linearly with tensile strength. When the yield zone length “a” remains constant, ΔK first decreases and then increases with increasing a/b ratio, reaching its minimum value when the a/b ratio is 0.6. ΔK shows a linear increase with interfacial tension and decreases with increasing wetting angle and initiation angle of cracking. The dissolution of carbonate minerals can considerably influence the propagation of microcracks. Initially, the impact of this dissolution may not be pronounced; however, as the duration of the rock samples' exposure to the dissolution process exceeds 100 h, the increase in the stress intensity factor becomes substantial. The increase in ΔK accelerates the propagation of microcracks within rocks. Constructing a shale microfracture propagation model based on dissolution effects is crucial for elucidating the microscopic mechanisms of mechanical–chemical coupled changes in shale microfractures, which is significant for analyzing wellbore stability.

众所周知，在页岩地层中，微裂缝的扩展会显著影响井筒的稳定性；然而，对溶解度的作用研究较少。在此基础上，考虑水化效应、毛细效应、强度弱化效应和溶蚀效应，建立了力学与化学耦合的页岩微裂缝扩展模型。将相关实验与模型相结合，揭示了微断裂扩展的机理。结果表明：ΔK（应力强度因子）随水化微机械力的增加呈上升趋势，当水化时间超过30 h时，ΔK的增加速度逐渐放缓；ΔK随抗拉强度线性增加。当屈服区长度a一定时，ΔK随a/b比的增大先减小后增大，在a/b比为0.6时达到最小值。ΔK随界面张力线性增大，随润湿角和裂纹起裂角的增大而减小。碳酸盐矿物的溶蚀作用对微裂纹的扩展有较大影响。最初，这种解散的影响可能不明显；然而，当岩样暴露于溶蚀过程的时间超过100 h时，应力强度因子的增加变得明显。ΔK的增加加速了岩石内部微裂纹的扩展。建立基于溶蚀效应的页岩微裂缝扩展模型，对于阐明页岩微裂缝力学-化学耦合变化的微观机制至关重要，对分析井筒稳定性具有重要意义。

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引用次数: 0

Numerical study of using dual sources constructed via deconvolution to suppress the collar waves in acoustic logging while drilling 随钻声波测井中利用反褶积构造双震源抑制领波的数值研究

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-28 DOI: 10.1016/j.geoen.2024.213549

Zhen Li , Junjun Guo , Jiayi Zhong , Chuang Hei , Xingjian Wang , Can Jiang

In the design of acoustic logging while drilling (LWD) instruments, acoustic isolation is crucial to prevent the loss of formation signals due to collar waves. A conventional approach involves carving periodic grooves on the drill collar to isolate collar waves, but this can compromise the mechanical integrity of the collar. In this paper, we introduce a novel method using dual sources to suppress collar waves generated by a monopole source. This method added a new near-source to the original acoustic LWD instrument, and its input signal is constructed via deconvolution. The effectiveness of this method is first verified using the finite-difference time domain (FDTD) in an infinite fluid medium. The amplitude ratio of the collar wave’s average frequency spectrum (0–20 kHz), excited by the deconvolution-type dual sources (DCDS), compared to a single far-source, is only 1.57%, effectively suppressing most of the collar waves. Since formations do not significantly affect the propagation characteristics of collar waves, this method remains effective in various formations, as corroborated by simulation results. Additionally, we applied the wave interference-based slowness-time-coherence (STC) method to successfully extract the formation P-wave velocity even when collar wave velocity and formation P-wave velocity are similar. This method provides an effective approach to suppress monopole collar waves without compromising the collar’s integrity and mechanical strength.

在随钻声波测井（LWD）仪器的设计中，声学隔离对于防止接箍波导致地层信号丢失至关重要。传统的方法是在钻铤上雕刻周期性的凹槽来隔离钻铤波动，但这可能会损害钻铤的机械完整性。本文介绍了一种利用双源抑制单极子源产生的环波的新方法。该方法在原有声波LWD仪器的基础上增加了一个新的近源，其输入信号通过反卷积构造。首先用时域有限差分（FDTD）在无限流体介质中验证了该方法的有效性。与单一远源相比，反卷积型双源（DCDS）激发的领波平均频谱（0-20 kHz）幅值比仅为1.57%，可有效抑制大部分领波。由于地层对领波的传播特性没有显著影响，因此模拟结果证实了该方法在各种地层中仍然有效。此外，我们应用基于波干涉的慢度-时间相干（STC）方法，成功地提取了地层纵波速度，即使在领波速度和地层纵波速度相似的情况下。这种方法提供了一种有效的方法来抑制单极项圈波动，而不影响项圈的完整性和机械强度。

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引用次数: 0

Carbon steel pipeline CO2 erosion-corrosion damage prediction model and numerical simulation research 碳钢管道CO2冲蚀损伤预测模型及数值模拟研究

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-28 DOI: 10.1016/j.geoen.2024.213558

Yuxuan Huang , Xiaochuan Wang , Kunpeng Lu , Jincheng Hu

CO₂ erosion-corrosion (E-C) represents a significant and pervasive threat to the integrity of carbon steel pipeline in the oil and gas industry, which has attracted more and more attention. On this basis, a CO₂ E-C damage prediction model considering the synergistic effect is established combining with multiphase flow model, corrosion model and CO₂ corrosion model, in which the Eulerian-Lagrangian discrete particle method is employed in the multiphase flow model and the CO₂ corrosion model is modified and verified by the erosion-corrosion test method. By using the CFD-DPM technology, the three-dimensional numerical simulation of the elbow is carried out to demonstrate the characteristics of the prediction model, and the dominant factors and extent of CO₂ E-C damage can be determined based on the numerical simulation results. Both erosion and corrosion are non-negligible parts that lead to CO₂ E-C damage, with corrosion factors being the more important factor to be considered. The prediction results can not only provide suggestions for improving the design of carbon steel pipelines in the oil and gas industry, but also provide protective measures for the operation of existing pipelines to extend their service life, which is helpful for the development and implementation of plans in the oil and gas industry.

二氧化碳侵蚀腐蚀（E-C）是油气行业中普遍存在的对碳钢管道完整性的重大威胁，已引起越来越多的关注。在此基础上，结合多相流模型、腐蚀模型和CO2腐蚀模型，建立了考虑协同效应的CO2 E-C损伤预测模型，其中多相流模型采用欧拉-拉格朗日离散颗粒法，CO2腐蚀模型通过侵蚀-腐蚀试验方法进行修正和验证。利用CFD-DPM技术对弯头进行了三维数值模拟，验证了预测模型的特点，并根据数值模拟结果确定了CO2 E-C损伤的主导因素和程度。侵蚀和腐蚀都是导致CO2 E-C损伤的不可忽视的部分，腐蚀因素是更重要的考虑因素。预测结果不仅可以为油气行业碳钢管道的设计改进提供建议，还可以为现有管道的运行提供保护措施，延长其使用寿命，对油气行业规划的制定和实施有所帮助。

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引用次数: 0

Propped fracture conductivity in shale oil reservoirs: Prediction model and influencing factors 页岩油储层支撑裂缝导流能力：预测模型及影响因素

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-28 DOI: 10.1016/j.geoen.2024.213537

Liang Zhang , Chuan He , Lixing Li , Ronghua Wen , Yuzhu Liang

Hydraulic fracturing is the main measure for stimulation of shale oil reservoirs, but the high content of clay minerals, well-developed bedding, and low mechanical strength of shale rock often result in a strong stress sensitivity of propped fractures associated with shale hydration expansion and proppant embedment in fracture wall. Especially under conditions of low sand laying concentration, the fracture conductivity can be greatly reduced. In this paper, a comprehensive prediction model of propped fracture conductivity in shale oil reservoirs was established, which considers the damage mechanisms of proppant compression, embedment, crushing, and shale hydration and expansion. The sensitivity analysis of factors affecting the fracture conductivity indicates that the proppant particle size, involved damage mechanisms, Kozeny-Carman coefficient, proppant layer number, and proppant density are the main factors to determine the fracture width and permeability and further affect the fracture conductivity. Most of the rest factors are related to the specific fracture damage mechanisms. The influence of shale hydration expansion is larger than that of proppant particle compression which is further larger than that of proppant crushing. In a real hydraulic fracture, the fracture width decreases from fracture heel to toe, caused by the non-uniform laying concentration of proppant. For the fracture near the wellbore usually with a large sand laying concentration, the influences of different factors are ranked as follows: proppant particle size > elastic modulus of proppant > fluid pressure > hydration expansion coefficient > filtration depth. For the front of the fracture with a low sand laying concentration, it is easy to close, which is sensitive to all the above factors. To achieve a high and stable fracture conductivity, the anti-swelling agent should be used to prevent shale hydration expansion. Large-size proppants with high elastic modulus should be selected to prop up the front of the fracture, and the decline of bottom-hole flow pressure should be controlled during the depressurized production process. The obtained results have a certain guiding significance for understanding the factors of shale fracture conductivity and the optimization of fracture parameters.

水力压裂是页岩油藏增产的主要措施，但由于粘土矿物含量高、层理发育、页岩机械强度低，往往导致支撑裂缝具有较强的应力敏感性，并与页岩水化膨胀和支撑剂嵌入裂缝壁上有关。特别是在低铺砂浓度条件下，裂缝导流能力会大大降低。建立了考虑支撑剂压缩、嵌入、破碎、页岩水化膨胀等破坏机理的页岩储层支撑裂缝导流能力综合预测模型。影响裂缝导流能力因素的敏感性分析表明，支撑剂粒径、损伤机理、Kozeny-Carman系数、支撑剂层数、支撑剂密度是决定裂缝宽度和渗透率的主要因素，进而影响裂缝导流能力。其余因素大多与特定的断裂损伤机制有关。页岩水化膨胀的影响大于支撑剂颗粒压缩的影响，进一步大于支撑剂破碎的影响。在真实的水力裂缝中，由于支撑剂的分布浓度不均匀，裂缝宽度从裂缝跟到裂缝趾逐渐减小。对于通常下砂浓度较大的井筒附近裂缝，不同因素对支撑剂的影响依次为：支撑剂粒径>；支撑剂弹性模量>；流体压力>；水化膨胀系数>；过滤深度。对于铺砂浓度较低的裂缝前缘，容易闭合，对上述因素都比较敏感。为了获得高且稳定的裂缝导流能力，应使用抗膨胀剂来防止页岩水化膨胀。应选择高弹性模量的大尺寸支撑剂支撑裂缝前缘，并在降压生产过程中控制井底流动压力的下降。所得结果对认识页岩裂缝导流性影响因素、优化裂缝参数具有一定的指导意义。

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引用次数: 0

Missing data interpolation in well logs based on generative adversarial network and improved krill herd algorithm 基于生成对抗网络和改进磷虾群算法的测井缺失数据插值

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-27 DOI: 10.1016/j.geoen.2024.213538

Fengtao Qu , Yuqiang Xu , Hualin Liao , Jiansheng Liu , Yanfeng Geng , Lei Han

Accurate logging data is crucial in geology and petroleum engineering for tasks such as geological modelling, reservoir simulation, and decision-making regarding well repair, water injection, and oil recovery. However, logging instrument failure occurs due to complex conditions such as high temperature and pressure, resulting in incomplete data and posing challenges for reservoir evaluation and development. The existing interpolation methods are primarily based on statistical and machine learning methods, lacking deep mining of hidden associations between logging items. Aiming at the problem of incomplete well-logging data, an incomplete well-logging data interpolation method based on a generative adversarial network and an improved krill herd algorithm is proposed. The results show that the proposed method has stable interpolation for well-logging data missing with different missing rates and any missing positions. Compared with other GANs (GAN, WGAN, and WGAN-GP), the RMSE of the proposed method is reduced by 57.63%, and the

R^{2}

is increased by 7.94%. The proposed method is compared with statistical methods (averaging and cubic spline interpolation) and machine learning methods (k-nearest neighbor, support vector machine, and random forest). The experimental results show that the proposed model has stable reconstruction performance for logging data with different missing rates and any missing positions.

在地质和石油工程中，准确的测井数据对于地质建模、油藏模拟以及修井、注水和采油决策等任务至关重要。然而，由于高温高压等复杂条件，测井仪器会发生故障，导致数据不完整，给储层评价和开发带来了挑战。现有的插值方法主要基于统计和机器学习方法，缺乏对日志项之间隐藏关联的深度挖掘。针对测井数据不完备的问题，提出了一种基于生成对抗网络和改进磷虾群算法的不完备测井数据插值方法。结果表明，该方法对不同缺失率和任意缺失位置的测井数据都具有稳定的插值效果。与其他GAN （GAN、WGAN和WGAN- gp）相比，该方法的RMSE降低了57.63%，R2提高了7.94%。将该方法与统计方法（平均和三次样条插值）和机器学习方法（k近邻、支持向量机和随机森林）进行了比较。实验结果表明，该模型对不同缺失率和任意缺失位置的测井数据具有稳定的重建性能。

{"title":"Missing data interpolation in well logs based on generative adversarial network and improved krill herd algorithm","authors":"Fengtao Qu , Yuqiang Xu , Hualin Liao , Jiansheng Liu , Yanfeng Geng , Lei Han","doi":"10.1016/j.geoen.2024.213538","DOIUrl":"10.1016/j.geoen.2024.213538","url":null,"abstract":"<div><div>Accurate logging data is crucial in geology and petroleum engineering for tasks such as geological modelling, reservoir simulation, and decision-making regarding well repair, water injection, and oil recovery. However, logging instrument failure occurs due to complex conditions such as high temperature and pressure, resulting in incomplete data and posing challenges for reservoir evaluation and development. The existing interpolation methods are primarily based on statistical and machine learning methods, lacking deep mining of hidden associations between logging items. Aiming at the problem of incomplete well-logging data, an incomplete well-logging data interpolation method based on a generative adversarial network and an improved krill herd algorithm is proposed. The results show that the proposed method has stable interpolation for well-logging data missing with different missing rates and any missing positions. Compared with other GANs (GAN, WGAN, and WGAN-GP), the RMSE of the proposed method is reduced by 57.63%, and the <span><math><mrow><msup><mi>R</mi><mn>2</mn></msup></mrow></math></span> is increased by 7.94%. The proposed method is compared with statistical methods (averaging and cubic spline interpolation) and machine learning methods (k-nearest neighbor, support vector machine, and random forest). The experimental results show that the proposed model has stable reconstruction performance for logging data with different missing rates and any missing positions.</div></div>","PeriodicalId":100578,"journal":{"name":"Geoenergy Science and Engineering","volume":"246 ","pages":"Article 213538"},"PeriodicalIF":0.0,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation on heat extraction performance of supercritical CO2 in depleted oil and gas reservoirs 枯竭油气藏超临界CO2抽热性能数值研究

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-27 DOI: 10.1016/j.geoen.2024.213557

Zhipeng Xu , Qi Jia , Jiayi Li , Tiantian Zhang , Dongliang Han , Yufei Tan , Bo Feng

Using supercritical CO₂ (sCO₂) for geothermal exploitation not only improves the heat extraction rate and saves injection-production energy consumption, but also gains environmental benefit of carbon sequestration. Compared to hot dry rock, depleted oil and gas reservoirs are nature porous reservoirs harboring abundant geothermal resources, in which artificial reservoir fracturing is unnecessary prior to the geothermal extraction. Besides, a lot of pre-existing oil-gas well networks along with ground facilities can be reutilized, significantly reducing geothermal drilling costs. This paper conducts a numerical investigation on using sCO₂ for heat extraction in depleted oil and gas reservoirs. Firstly, A coupled wellbore-reservoir model is established to analyze the flow and heat transfer characteristics of sCO₂ in the reservoir and injection-production well. Secondly, the variation of sCO₂ gas saturation, production temperature, production rate and heat extraction rate are studied. Finally, the influence of different factors on sCO₂ heat extraction performance is examined. The results indicate that the maximum sCO₂ heat extraction rate is 18.45 MW, and the temperature rise of sCO₂ within the reservoir is still higher than 24 °C after 30 years. To enhance sCO₂ heat extraction performance, reducing injection temperature, increasing production pressure and well spacing are advisable. In the case of multi-well scheme, a higher ratio of production wells to injection wells and a decentralized arrangement pattern are encouraged. The findings of this paper are anticipated to provide theoretical basis and technical support for efficient geothermal harvest in depleted oil and gas reservoirs and potential appropriate option in building heating.

利用超临界CO2 （sCO2）进行地热开发，不仅提高了采热率，节约了注采能耗，而且具有固碳的环境效益。与热干岩相比，枯竭油气藏是天然多孔储层，蕴藏着丰富的地热资源，在地热开采前无需进行人工压裂。此外，许多现有的油气井网络和地面设施可以重新利用，大大降低了地热钻井成本。本文对枯竭油气藏利用sCO2采热进行了数值研究。首先，建立井储耦合模型，分析储层和注采井中sCO2的流动和传热特征。其次，研究了sCO2气饱和度、产温、产率和抽热率的变化规律。最后，考察了不同因素对sCO2抽热性能的影响。结果表明：最大sCO2抽热率为18.45 MW， 30年后库内sCO2温升仍高于24℃；为提高sCO2热抽采性能，建议降低注入温度、提高生产压力和井距。在多井方案中，鼓励提高生产井与注水井的比例，并采用分散的布置方式。本文的研究成果有望为枯竭油气藏的高效地热开采和建筑采暖的合理选择提供理论依据和技术支持。

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引用次数: 0

Comprehensive analysis of gas slippage and Non-Darcy flow in carbonate rock samples under stress conditions 应力条件下碳酸盐岩样品气滑及非达西渗流综合分析

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-27 DOI: 10.1016/j.geoen.2024.213547

Milad Farahani , Hamed Aghaei , Yazdan Faraji

This study examines the influence of stress on gas slippage and non-Darcy flow behavior in carbonate porous media, using core samples from two large carbonate reservoirs in the Middle East. Permeability measurements under varying stress conditions revealed significant increases in both the gas slippage factor and the non-Darcy coefficient with rising stress, indicating a related decrease in permeability. A new mathematical model, incorporating effective tortuosity and slippage radius into the Kozeny-Carman equation, was developed to accurately describe the stress-dependent nature of gas flow. Analysis of key pore attributes—such as porosity, pore size, shape, and tortuosity—underscored the critical role of pore structure, especially pore size and connectivity, in governing fluid flow under stress. These findings highlight the need to account for stress effects in reservoir engineering for improved modeling and management of carbonate reservoirs.

本研究利用中东两个大型碳酸盐岩储层的岩心样品，研究了应力对碳酸盐岩多孔介质中气体滑移和非达西流动行为的影响。在不同应力条件下的渗透率测量显示，随着应力的增加，气滑系数和非达西系数都显著增加，表明渗透率相应降低。建立了一种新的数学模型，将有效挠度和滑移半径纳入Kozeny-Carman方程，以准确描述气体流动的应力依赖性。对孔隙度、孔径、形状和弯曲度等关键孔隙属性的分析强调了孔隙结构（尤其是孔径和连通性）在控制应力下流体流动中的关键作用。这些发现强调了在储层工程中考虑应力效应以改进碳酸盐岩储层建模和管理的必要性。

引用次数: 0

A new division of late Cretaceous Erlian Basin tectonic units based on differential basement characteristics 基于差异基底特征的晚白垩世二连盆地构造单元新划分

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-26 DOI: 10.1016/j.geoen.2024.213536

Sheng Fu , Zhen Liu , Lijun Song , Jiawang Ge , Ning Tian , Kewei Yin , Xin Wang

The Erlian Basin, a significant continental sedimentary basin in northeastern China, is renowned for its abundant hydrocarbon resources. Extensive research has been conducted on its sedimentary sequences, hydrocarbon accumulation, and geodynamic background. However, previous tectonic units classifications of the Erlian Basin predominantly reflect its post-Cenozoic tectonic framework, neglecting the Early Cretaceous period. This oversight fails to explain recent petroleum discoveries in the Wulanhua area of the Ondor Sum Uplift. In this study, geological, well log, seismic, gravity, and magnetic data, along with large, deep fault distributions and the regional geology of the Erlian Basin, were utilized to analyze its basement characteristics and propose a new tectonic division. Our findings reveal that the Erlian Basin's basement exhibits composite characteristics, resulting in a north-south zonation of basin depressions. Consequently, the basin's tectonic units were divided into northern, central, and southern depressions, delineated by two major deep faults: Xilinhot and Chifeng–Kaiyuan. This revised tectonic division clarifies the Early Cretaceous tectonic framework, enhances the basin's hydrocarbon exploration potential, and will guide future exploration efforts. Our study identifies nine favorable sags within the Erlian Basin with significant hydrocarbon potential.

二连盆地是中国东北重要的陆相沉积盆地，以其丰富的油气资源而闻名。对其沉积层序、油气成藏和地球动力学背景进行了广泛的研究。然而，以往二连盆地的构造单元划分主要反映了其后新生代的构造格局，忽略了早白垩世的构造格局。这种疏忽不能解释最近在奥多尔隆起乌兰花地区发现的石油。利用地质、测井、地震、重磁等资料，结合二连盆地大深断裂分布和区域地质，分析了二连盆地基底特征，提出了新的构造分区。研究结果表明，二连盆地基底呈现复合型特征，盆地坳陷呈南北分带分布。据此，盆地的构造单元划分为北、中、南3个坳陷，并以锡林浩特和赤峰-开元两条大深断裂为界。修正后的构造划分明确了早白垩世构造格架，增强了盆地油气勘探潜力，对今后的勘探工作具有指导意义。在二连盆地内确定了9个有利凹陷，具有较大的油气潜力。

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引用次数: 0

Creep mechanical behavior and damage characteristics of laminated slate under thermal-mechanical coupling 热-力耦合作用下层状板岩的蠕变力学行为及损伤特征

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-26 DOI: 10.1016/j.geoen.2024.213535

Haopeng Jiang, Annan Jiang

To study the long-term stability of geothermal tunnels within a laminated rock mass, creep tests were conducted on slate with different bedding angles under different temperatures. In this study, we investigated the creep rate and macroscopic failure characteristics of slate with various bedding angles (0–90°). The coupled damage was considered, and combining with the unsteady fractional order theory, a constitutive model that can describe nonlinear behavior of laminated slate under thermal loading was established. The results show that gradual increases in temperature from 20 to 150 °C and loading from 10 to 115 MPa lead to increased rock damage, which leads to accelerated creep and eventual failure of the rock. The long-term strengths of slate with a bedding angle of 0 °C at temperatures of 20, 50, 80, 110, and 150 °C were found to be 126.21, 118.25, 106.18, 94.58, and 85.14 MPa, respectively, and its mechanical properties exhibited anisotropy. The proposed creep model effectively captures the three-stage creep characteristics of high-temperature layered rocks. The results of this study provide theoretical guidance for the long-term stability assessment of geothermal drilling in surrounding rock.

为了研究地热隧道在层状岩体中的长期稳定性，对不同层理角度的板岩在不同温度下进行了蠕变试验。研究了不同层理角度（0 ~ 90°）板岩的蠕变速率及宏观破坏特征。在考虑耦合损伤的基础上，结合非定常分数阶理论，建立了能描述层状板岩在热载荷作用下非线性行为的本构模型。结果表明：温度从20℃逐渐升高到150℃，加载从10 MPa逐渐升高到115 MPa，岩石损伤程度增加，导致岩石蠕变加速，最终破坏；在20、50、80、110和150℃温度下，0℃层理角板岩的长期强度分别为126.21、118.25、106.18、94.58和85.14 MPa，其力学性能表现出各向异性。所建立的蠕变模型有效地反映了高温层状岩石的三阶段蠕变特征。研究结果为地热钻井围岩长期稳定性评价提供了理论指导。

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引用次数: 0

Binary composite depolymerization system targeting polymer injection wells: A fusion of experiment and mechanism 以注聚井为目标的二元复合解聚体系：实验与机理的融合

0 ENERGY & FUELS

Geoenergy Science and Engineering

Pub Date : 2024-11-26 DOI: 10.1016/j.geoen.2024.213552

Xiang Chen , Kexin Liu , Pingli Liu , Yangyang Fu , Juan Du , Chengjie Wang , Jinming Liu

With the continuous development and application of polymer flooding technology, the problem of polymer injection well blockage has become increasingly severe, and various plugging removal technologies have emerged. This paper studies the depolymerization agent system, aiming at the blockage problem caused by the injection of polymer HLCHEM-P01 in the mine. The depolymerization agent system is evaluated through gel chromatography analysis, corrosion evaluation, pH sensitivity evaluation, and core displacement experiment. Finally, an efficient, safe, low corrosion and reliable binary compound depolymerization agent system was obtained. It can almost wholly degrade the polymer solution after 90 min. Analyze the mechanism of action of the binary compound depolymerization agent system, which involves specific antagonistic or synergistic interactions. The overall oxidation performance of mixed chemical agents is not just a simple superposition of the oxidation performance of individual chemical agents. The application effect of the depolymerization agent system is significant, and the core permeability recovery reaches over 90%. Effectively solving blockage problems can help improve oilfield efficiency and increase crude oil recovery.

随着聚合物淹没技术的不断发展和应用，聚合物注入井堵塞问题日益严重，各种除堵技术应运而生。本文针对矿井中注入聚合物 HLCHEM-P01 引起的堵塞问题，研究了解聚剂系统。通过凝胶色谱分析、腐蚀评估、pH 值敏感性评估和岩心置换实验，对解聚剂系统进行了评估。最终获得了一种高效、安全、低腐蚀、可靠的二元化合物解聚剂系统。90 分钟后，它几乎可以完全降解聚合物溶液。分析二元化合物解聚剂体系的作用机理，其中涉及特定的拮抗或协同作用。混合化学剂的整体氧化性能并不仅仅是单个化学剂氧化性能的简单叠加。解聚剂体系的应用效果显著，岩心渗透率恢复可达 90% 以上。有效解决堵塞问题有助于提高油田效率，增加原油采收率。

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引用次数: 0