Petroleum Science最新文献_第10页

The genesis and accumulation mechanism of CBM in the typical mid- to low-rank coal-bearing basins 典型中低煤阶盆地煤层气成因及成藏机制

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.04.017

Bin Zhang , Shu Tao , Fan Yang , Yi Cui , Qing-He Jing , Jie Guo , Shi-Da Chen , Yi-Jie Wen , Xin-Yang Men

The composition and isotopic characteristics of coalbed methane (CBM), as well as the genesis of CH₄ and CO₂, associated geological process and migration-accumulation model of CBM in typical mid- to low-rank coal-bearing basins were studied. The genesis of CBM is jointly influenced by the degree of coalification and biochemical processes, which in turn determine the composition and isotopic characteristics of CBM. Biogenic gas is extensively developed in mid- to low-rank coal-bearing basins, but its genesis varies. In the Baode area, China, and the San Juan Basin, USA, CBM is mainly secondary biogenic gas and thermogenic gas. In the Miquan area, China, CBM is characterized by primary biogenic gas. However, CBM in the Jiergalangtu area, China, Surat Basin, Australia, and Power River Basin, USA, are characterized by secondary biogenic gas. Microbial CO₂ reduction occurs in these coal-bearing basins, but with significant gas generation by acetate fermentation in some areas of these basins. Moreover, CO₂ in the Power River Basin, Surat Basin, and Jiergalangtu area mainly originates from microbial degradation of organic matter. However, in other basins studied, CO₂ initially derives from coal pyrolysis and is subsequently supplemented by CO₂ from microbial methanogenesis. The generation and isotope fractionation of CBM are affected and controlled by associated geological processes. Additionally, under the control of tectonic morphology and hydrogeological conditions, the genesis and migration-accumulation models of CBM in mid- to low-rank coal-bearing basins can be summarized into two models—the hydrodynamic active monoclinic model and the hydrodynamic differential syncline model—or a combination of the two.

研究了典型中低煤阶含煤盆地煤层气组成、同位素特征、CH4和CO2成因、相关地质过程和煤层气运聚模式。煤化程度和生物化学过程共同影响煤层气的成因，进而决定了煤层气的组成和同位素特征。中低层含煤盆地广泛发育生物气，但成因各异。在中国宝德地区和美国圣胡安盆地，煤层气主要为次生生物气和热成因气。中国米泉地区煤层气以原生生物气为主要特征。而中国吉尔嘎朗图地区、澳大利亚苏拉特盆地和美国动力河盆地的煤层气则以次生生物气为主。这些含煤盆地中存在微生物CO2还原作用，但在部分地区存在显著的醋酸发酵生气作用。Power River流域、Surat盆地和吉尔嘎朗图地区的CO2主要来源于有机物的微生物降解。然而，在研究的其他盆地中，二氧化碳最初来自煤热解，随后由微生物产甲烷补充。煤层气的生成和同位素分馏受伴生地质作用的影响和控制。此外，在构造形态和水文地质条件的控制下，中低阶含煤盆地煤层气的成因和运聚模式可归纳为水动力活动单斜模式和水动力差向斜模式，或两者相结合。

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引用次数: 0

Analysis of seismic dispersion and attenuation for gas-hydrate formations in the South China Sea 南海天然气水合物地层地震频散与衰减分析

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.05.008

Zuo-Xiu He , Feng Zhang , Pin-Bo Ding , Xiang-Yang Li , Hai-Feng Chen

Existing studies indicate that gas hydrate-bearing formations exhibit notable seismic velocity dispersion and attenuation. The Shenhu area of the South China Sea hold significant gas hydrate resource potential; however, the relationship between seismic velocity dispersion, attenuation properties, and gas-hydrate saturation remains insufficiently understood. Furthermore, a significant mismatch exists between the real seismic angle gather near a well and the synthetic angle gather generated using the convolution method, and this discrepancy may arise from the seismic velocity dispersion and attenuation characteristics of the gas hydrate-bearing formations. In this paper, we develop a rock physics model that integrates White's and Dvorkin's models, accounting for varied types of gas-hydrate occurrence states, specifically tailored to the gas hydrate-bearing formations in the Shenhu area. This model is calibrated with well log data and employed to investigate how gas-hydrate saturation influences seismic velocity dispersion and attenuation. Numerical analysis reveals the coexistence of two types of gas-hydrate occurrence states in the region: high gas-hydrate saturation formations are dominated by load-bearing-type gas hydrate, and formations containing both gas hydrate and free gas may exhibit either load-bearing or pore-filling types. The seismic velocity dispersion and attenuation properties vary significantly depending on the gas-hydrate occurrence state. We further apply the proposed model to generate seismic velocity and attenuation logs at various frequencies. These logs are used in seismic forward modeling employing both the convolution method and the propagator matrix method. Well tie analysis indicates that the synthetic angle gather incorporating attenuation via the propagator matrix method aligns more closely with the real seismic angle gather than the convolution method. This study provides valuable insights into frequency-dependent amplitude versus offset (AVO) analysis and the seismic interpretation of gas hydrate-bearing formations in the South China Sea.

已有研究表明，含天然气水合物地层具有明显的地震速度频散和衰减。南海神狐海域具有重要的天然气水合物资源潜力；然而，地震速度频散、衰减特性和天然气水合物饱和度之间的关系仍然没有得到充分的了解。此外，利用卷积方法得到的井附近真实地震角集与合成地震角集之间存在明显的不匹配，这种差异可能与含天然气水合物地层的地震速度频散和衰减特征有关。在本文中，我们建立了一个结合White's和Dvorkin's模型的岩石物理模型，考虑了不同类型的天然气水合物赋存状态，并专门针对神狐地区的含天然气水合物地层进行了研究。该模型使用测井数据进行校准，并用于研究天然气水合物饱和度对地震速度频散和衰减的影响。数值分析表明，区内两种类型的天然气水合物赋存状态并存：高水合物饱和度地层以承载型天然气水合物为主，含天然气水合物和游离气的地层既可能呈现承载型，也可能呈现充孔型。地震速度的频散和衰减特性随水合物赋存状态的不同而有显著差异。我们进一步应用所提出的模型来生成不同频率的地震速度和衰减日志。利用卷积法和传播矩阵法将这些测井曲线用于地震正演模拟。井缝分析表明，与卷积法相比，采用传播子矩阵法计算衰减的合成角集更接近真实地震角集。该研究为南海含天然气水合物地层的频率相关振幅相对偏移（AVO）分析和地震解释提供了有价值的见解。

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引用次数: 0

A large-scale, high-quality dataset for lithology identification: Construction and applications 用于岩性识别的大规模高质量数据集：构建和应用

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.04.013

Jia-Yu Li , Ji-Zhou Tang , Xian-Zheng Zhao , Bo Fan , Wen-Ya Jiang , Shun-Yao Song , Jian-Bing Li , Kai-Da Chen , Zheng-Guang Zhao

Lithology identification is a critical aspect of geoenergy exploration, including geothermal energy development, gas hydrate extraction, and gas storage. In recent years, artificial intelligence techniques based on drill core images have made significant strides in lithology identification, achieving high accuracy. However, the current demand for advanced lithology identification models remains unmet due to the lack of high-quality drill core image datasets. This study successfully constructs and publicly releases the first open-source Drill Core Image Dataset (DCID), addressing the need for large-scale, high-quality datasets in lithology characterization tasks within geological engineering and establishing a standard dataset for model evaluation. DCID consists of 35 lithology categories and a total of 98,000 high-resolution images (512 × 512 pixels), making it the most comprehensive drill core image dataset in terms of lithology categories, image quantity, and resolution. This study also provides lithology identification accuracy benchmarks for popular convolutional neural networks (CNNs) such as VGG, ResNet, DenseNet, MobileNet, as well as for the Vision Transformer (ViT) and MLP-Mixer, based on DCID. Additionally, the sensitivity of model performance to various parameters and image resolution is evaluated. In response to real-world challenges, we propose a real-world data augmentation (RWDA) method, leveraging slightly defective images from DCID to enhance model robustness. The study also explores the impact of real-world lighting conditions on the performance of lithology identification models. Finally, we demonstrate how to rapidly evaluate model performance across multiple dimensions using low-resolution datasets, advancing the application and development of new lithology identification models for geoenergy exploration.

岩性识别是地热能开发、天然气水合物开采和天然气储存等地球能源勘探的一个重要方面。近年来，基于岩心图像的人工智能技术在岩性识别方面取得了重大进展，实现了较高的岩性识别精度。然而，由于缺乏高质量的岩心图像数据集，目前对先进岩性识别模型的需求仍未得到满足。本研究成功构建并公开发布了首个开源岩心图像数据集（DCID），解决了地质工程中岩性表征任务对大规模、高质量数据集的需求，并为模型评估建立了标准数据集。DCID包括35个岩性类别，共9.8万张高分辨率图像（512 × 512像素），是岩性类别、图像数量和分辨率最全面的岩心图像数据集。该研究还为流行的卷积神经网络（cnn）（如VGG， ResNet, DenseNet, MobileNet）以及基于DCID的视觉变压器（ViT）和MLP-Mixer提供了岩性识别精度基准。此外，还评估了模型性能对各种参数和图像分辨率的敏感性。为了应对现实世界的挑战，我们提出了一种现实世界数据增强（RWDA）方法，利用DCID的轻微缺陷图像来增强模型的鲁棒性。该研究还探讨了现实世界光照条件对岩性识别模型性能的影响。最后，我们展示了如何使用低分辨率数据集在多个维度上快速评估模型的性能，从而推进了新岩性识别模型在地球能源勘探中的应用和开发。

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引用次数: 0

Study on S-wave velocity prediction in shale reservoirs based on explainable 2D-CNN under physical constraints 物理约束下基于可解释2D-CNN的页岩储层横波速度预测研究

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.04.027

Zhi-Jun Li , Shao-Gui Deng , Yu-Zhen Hong , Zhou-Tuo Wei , Lian-Yun Cai

The shear wave (S-wave) velocity is a critical rock elastic parameter in shale reservoirs, especially for evaluating shale fracability. To effectively supplement S-wave velocity under the condition of no actual measurement data, this paper proposes a physically-data driven method for the S-wave velocity prediction in shale reservoirs based on the class activation mapping (CAM) technique combined with a physically constrained two-dimensional Convolutional Neural Network (2D-CNN). High-sensitivity log curves related to S-wave velocity are selected as the basis from the data sensitivity analysis. Then, we establish a petrophysical model of complex multi-mineral components based on the petrophysical properties of porous medium and the Biot-Gassmann equation. This model can help reduce the dispersion effect and constrain the 2D-CNN. In deep learning, the 2D-CNN model is optimized using the Adam, and the class activation maps (CAMs) are obtained by replacing the fully connected layer with the global average pooling (GAP) layer, resulting in explainable results. The model is then applied to wells A, B1, and B2 in the southern Songliao Basin, China and compared with the unconstrained model and the petrophysical model. The results show higher prediction accuracy and generalization ability, as evidenced by correlation coefficients and relative errors of 0.98 and 2.14%, 0.97 and 2.35%, 0.96 and 2.89% in the three test wells, respectively. Finally, we present the defined C-factor as a means of evaluating the extent of concern regarding CAMs in regression problems. When the results of the petrophysical model are added to the 2D feature maps, the C-factor values are significantly increased, indicating that the focus of 2D-CNN can be significantly enhanced by incorporating the petrophysical model, thereby imposing physical constraints on the 2D-CNN. In addition, we establish the SHAP model, and the results of the petrophysical model have the highest average SHAP values across the three test wells. This helps to assist in proving the importance of constraints.

横波速度是页岩储层中一个重要的岩石弹性参数，对评价页岩可压性尤为重要。为了在没有实际测量数据的情况下有效补充横波速度，本文提出了一种基于类激活映射（CAM）技术与物理约束二维卷积神经网络（2D-CNN）相结合的物理数据驱动页岩储层横波速度预测方法。从数据敏感性分析中选择与横波速度相关的高灵敏度测井曲线作为依据。在此基础上，根据多孔介质的岩石物理性质和Biot-Gassmann方程建立了复杂多矿物组分的岩石物理模型。该模型可以减少色散效应，约束2D-CNN。在深度学习中，使用Adam对2D-CNN模型进行优化，用全局平均池化（GAP）层代替完全连接层获得类激活图（CAMs），得到可解释的结果。将该模型应用于松辽盆地南部A、B1、B2井，并与无约束模型和岩石物理模型进行了对比。3口试井的相关系数和相对误差分别为0.98和2.14%、0.97和2.35%、0.96和2.89%，具有较高的预测精度和泛化能力。最后，我们提出定义的c因子作为评估回归问题中对cam的关注程度的手段。当将岩石物理模型的结果加入到2D特征图中时，c因子值显著增加，表明加入岩石物理模型可以显著增强2D- cnn的焦点，从而对2D- cnn施加物理约束。此外，建立了岩石物理模型，得到了3口测试井的平均SHAP值最高的结果。这有助于证明约束的重要性。

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引用次数: 0

Pressure transient behavior of fractured wells in multilayered tight gas reservoirs with heterogeneous properties and limited fracture height 非均质裂缝高度有限的多层致密气藏压裂井压力瞬态特征

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.05.002

Jing-Jing Guo, Chao-Zhi Jiang, Hai-Tao Wang, Lie-Hui Zhang

Hydraulic fracturing and commingle production of multiple layers are extensively adopted in unconventional tight gas reservoirs. Accurate determination of parameters of individual layers in multilayered tight gas reservoirs is essential for well performance evaluation and development strategy optimization. However, most analytical models for fractured vertical wells in stratified gas reservoirs focus on fully penetrated hydraulic fractures, neglecting the influence of partial penetration of hydraulic fractures. This paper presents a semi-analytical model to investigate the transient pressure behavior of vertically fractured wells in dual porosity multi-layered tight gas reservoirs. The partial penetration of hydraulic fracture, the vertical heterogeneities of layer properties, the differences between hydraulic fracture lengths in each layer and the stress sensitivity are all incorporated in the proposed model. The point-source solution, Laplace transformation, Fourier transformation, Pedrosa's transformation, perturbation technique, and the superposition principle are applied to obtain the analytical solution of transient pressure responses. The proposed model is validated against a commercial software, and the transient pressure behavior of vertically fractured wells in multi-layered tight gas reservoirs are analyzed. Based on the characteristics of the type curves, seven flow regimes can be identified, including wellbore storage, transitional flow period, reservoir linear flow period, vertical pseudo-radial flow in fracture system, inter-porosity flow period, late-time pseudo-radial flow period, and the boundary-dominated flow period. Sensitivity analyses reveal that the penetration ratio of hydraulic fracture has primary influence on early-time transient pressure behavior and production contribution, while the stress sensitivity mainly affects the late-time transient pressure behavior. Gas production at the initial stage is mainly contributed by the high-pressure/high-permeability layer, and gas backflow will occur during initial production stage for obviously unequal initial formation pressures. Finally, two field cases are conducted to illustrate the applicability of the proposed model. The model and corresponding conclusions can provide technical support for performance analysis of tight gas reservoirs.

非常规致密气藏广泛采用水力压裂和多层混采。多层致密气藏各层参数的准确确定是评价气井动态和优化开发策略的关键。然而，大多数层状气藏压裂直井分析模型关注的是水力裂缝全贯通，忽略了水力裂缝部分贯通的影响。本文建立了双孔隙度多层致密气藏垂直压裂井瞬态压力特征的半解析模型。该模型考虑了水力裂缝的部分穿透性、层性的垂向非均质性、各层水力裂缝长度的差异以及应力敏感性。采用点源解、拉普拉斯变换、傅立叶变换、佩德罗萨变换、摄动技术和叠加原理得到了瞬态压力响应的解析解。利用商业软件对模型进行了验证，并对多层致密气藏垂直压裂井的瞬态压力特征进行了分析。根据类型曲线特征，可识别出井筒储集、过渡流动、储层线性流动、裂缝体系垂直伪径向流动、孔隙间流动、后期伪径向流动和边界主导流动等7种流动阶段。敏感性分析表明，水力裂缝侵彻比对早期瞬态压力行为和产量贡献有主要影响，而应力敏感性主要影响后期瞬态压力行为。初期产气主要由高压/高渗层贡献，由于初始地层压力明显不均匀，初期生产阶段会发生气体倒流。最后，通过两个实例说明了所提模型的适用性。该模型及相应结论可为致密气藏动态分析提供技术支持。

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引用次数: 0

A new model for determining the effective permeability of tight reservoirs based on Fractal-Monte Carlo method 基于分形-蒙特卡罗方法确定致密储层有效渗透率的新模型

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.04.016

You Zhou , Song-Tao Wu , Ru-Kai Zhu , Xiao-Hua Jiang , Gan-Lin Hua

In contrast to conventional reservoirs, tight formations have more complex pore structures and significant boundary layer effect, making it difficult to determine the effective permeability. To address this, this paper first proposes a semi-empirical model for calculating boundary layer thickness based on dimensional analysis, using published experimental data on microcapillary flow. Furthermore, considering the non-uniform distribution of fluid viscosity in the flow channels of tight reservoirs, a theoretical model for boundary layer thickness is established based on fractal theory, and permeability predictions are conducted through Monte Carlo simulations. Finally, sensitivity analyses of various influencing parameters are performed. The results show that, compared to other fractal-based analytical models, the proposed permeability probabilistic model integrates parameters affecting fluid flow with random numbers, reflecting both the fractal and randomness characteristics of capillary size distribution. The computational results exhibit the highest consistency with experimental data. Among the factors affecting the boundary layer, in addition to certain conventional physical and mechanical parameters, different microstructure parameters significantly influence the boundary layer as well. A higher tortuosity fractal dimension results in a thicker boundary layer, while increases in pore fractal dimension, porosity, and maximum capillary size help mitigate the boundary layer effect. It is also observed that the permeability of large pores exhibits greater sensitivity to changes in various influencing parameters. Considering micro-scale flow effects, the proposed model enhances the understanding of the physical mechanisms of fluid transport in dense porous media.

与常规储层相比，致密储层孔隙结构更为复杂，边界层效应显著，有效渗透率难以确定。为了解决这一问题，本文首先利用已发表的微毛细管流动实验数据，提出了基于量纲分析计算边界层厚度的半经验模型。考虑致密储层流道中流体粘度的不均匀分布，基于分形理论建立了边界层厚度的理论模型，并通过蒙特卡罗模拟对渗透率进行了预测。最后，对各影响参数进行了敏感性分析。结果表明，与其他基于分形的分析模型相比，所建立的渗透率概率模型将影响流体流动的参数与随机数相结合，反映了毛细管尺寸分布的分形和随机性特征。计算结果与实验数据具有较高的一致性。在影响边界层的因素中，除了某些常规的物理力学参数外，不同的微观结构参数对边界层也有显著的影响。弯曲度分形维数越高，边界层越厚，孔隙分形维数、孔隙度和最大毛管尺寸的增加有助于减轻边界层效应。大孔隙渗透率对各种影响参数的变化表现出更大的敏感性。该模型考虑了微观尺度的流动效应，增强了对致密多孔介质中流体运移物理机制的理解。

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引用次数: 0

Stepwise inversion method using second-order derivatives of elastic impedance for fracture detection in orthorhombic medium 基于弹性阻抗二阶导数的正交介质裂缝探测逐步反演方法

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.04.026

Wei Xiang , Xing-Yao Yin , Kun Li , Zheng-Qian Ma , Ya-Ming Yang

Reservoirs with a group of vertical fractures in a vertical transversely isotropic (VTI) background are considered as orthorhombic (ORT) medium. However, fracture detection in ORT medium using seismic inversion methods remains challenging, as it requires the estimation of more than eight parameters. Assuming the reservoir to be a weakly anisotropic ORT medium with small contrasts in the background elastic parameters, a new azimuthal elastic impedance equation was first derived using parameter combinations and mathematical approximations. This equation exhibited almost the same accuracy as the original equation and contained only six model parameters: the compression modulus, anisotropic shear modulus, anisotropic compression modulus, density, normal fracture weakness, and tangential fracture weakness. Subsequently, a stepwise inversion method using second-order derivatives of the elastic impedance was developed to estimate these parameters. Moreover, the Thomsen anisotropy parameter, epsilon, was estimated from the inversion results using the ratio of the anisotropic compression modulus to the compression modulus. Synthetic examples with moderate noise and field data examples confirm the feasibility and effectiveness of the inversion method. The proposed method exhibited accuracy similar to that of previous inversion strategies and could predict richer vertical fracture information. Ultimately, the method was applied to a three-dimensional work area, and the predictions were consistent with logging and geological a priori information, confirming the effectiveness of this method. Summarily, the proposed stepwise inversion method can alleviate the uncertainty of multi-parameter inversion in ORT medium, thereby improving the reliability of fracture detection.

在垂直横向各向同性（VTI）背景下具有一组垂直裂缝的储层被认为是正交型（ORT）介质。然而，利用地震反演方法在ORT介质中进行裂缝检测仍然具有挑战性，因为它需要估计8个以上的参数。假设储层为弱各向异性ORT介质，背景弹性参数差异较小，首先利用参数组合和数学近似推导出新的方位弹性阻抗方程。该方程与原方程具有几乎相同的精度，仅包含6个模型参数：压缩模量、各向异性剪切模量、各向异性压缩模量、密度、正向断裂强度和切向断裂强度。随后，提出了一种利用弹性阻抗二阶导数的逐步反演方法来估计这些参数。此外，利用各向异性压缩模量与压缩模量之比，从反演结果中估计Thomsen各向异性参数epsilon。噪声适中的综合算例和现场实测算例验证了该反演方法的可行性和有效性。该方法具有与以往反演策略相似的精度，可以预测更丰富的垂向裂缝信息。最后，将该方法应用于三维工作区域，预测结果与测井和地质先验信息一致，验证了该方法的有效性。综上所述，所提出的逐步反演方法可以减轻ORT介质中多参数反演的不确定性，从而提高裂缝检测的可靠性。

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引用次数: 0

Full waveform inversion with fractional anisotropic total p-variation regularization 分数各向异性全p变差正则化全波形反演

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.05.004

Bo Li , Xiao-Tao Wen , Yu-Qiang Zhang , Zi-Yu Qin , Zhi-Di An

Full waveform inversion is a precise method for parameter inversion, harnessing the complete wavefield information of seismic waves. It holds the potential to intricately characterize the detailed features of the model with high accuracy. However, due to inaccurate initial models, the absence of low-frequency data, and incomplete observational data, full waveform inversion (FWI) exhibits pronounced nonlinear characteristics. When the strata are buried deep, the inversion capability of this method is constrained. To enhance the accuracy and precision of FWI, this paper introduces a novel approach to address the aforementioned challenges—namely, a fractional-order anisotropic total p-variation regularization for full waveform inversion (FATpV-FWI). This method incorporates fractional-order total variation (TV) regularization to construct the inversion objective function, building upon TV regularization, and subsequently employs the alternating direction multiplier method for solving. This approach mitigates the step effect stemming from total variation in seismic inversion, thereby facilitating the reconstruction of sharp interfaces of geophysical parameters while smoothing background variations. Simultaneously, replacing integer-order differences with fractional-order differences bolsters the correlation among seismic data and diminishes the scattering effect caused by integer-order differences in seismic inversion. The outcomes of model tests validate the efficacy of this method, highlighting its ability to enhance the overall accuracy of the inversion process.

全波形反演是利用地震波的完整波场信息进行参数反演的一种精密方法。它具有以高精度复杂地表征模型的详细特征的潜力。然而，由于初始模型不准确，缺乏低频数据和不完整的观测数据，全波形反演（FWI）表现出明显的非线性特征。当地层埋深时，该方法的反演能力受到限制。为了提高FWI的准确性和精度，本文引入了一种新的方法来解决上述挑战，即分数阶各向异性全p变差正则化全波形反演（FATpV-FWI）。该方法在TV正则化的基础上，采用分数阶全变分（TV）正则化构造反演目标函数，然后采用交替方向乘子法求解。该方法减轻了地震反演中总变差带来的阶跃效应，从而在平滑背景变化的同时，便于重建地球物理参数的尖锐界面。同时，用分数阶差分代替整数阶差分增强了地震数据之间的相关性，减小了地震反演中整数阶差分带来的散射效应。模型试验结果验证了该方法的有效性，突出了其提高反演过程整体精度的能力。

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引用次数: 0

Comparison of original and de-asphalted crude oils during formation of HCl-induced emulsion and sludge 原始原油和脱沥青原油在盐酸乳化和污泥形成过程中的比较

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.05.003

Ahmad Abbasi , M. Reza Malayeri , Maysam Mohammadzadeh-Shirazi

Stable HCl-crude oil emulsion and its subsequent sludge formation, with detrimental impacts on oil production, may stem from acid stimulation. One major ambiguity in this process is to discern the most influential component of crude oil on the stability of formed emulsions. This fundamental question has not adequately been addressed in previous studies. In this work, the impact of de-asphalted part of crude oil (maltene) has been investigated on the acid-induced emulsion and sludge separately. Accordingly, the emulsion phase separation and the amount of formed sludge have been compared for four crude oils and their maltene samples for different concentrations of ferric ion and acidic pH values. The results of phase separation, as a criterion for emulsion stability, showed that crude oil samples formed 6 to 25 percent more stable emulsions than maltene samples, when using blank HCl. The emulsions of maltene and spent acid (pH = 2) broke completely during the first 15 min after emulsification. In addition, the maltene components usually had less contribution to sludge formation in the presence of blank HCl. It was concluded that asphaltene is the key component during interaction with HCl. However, the maltene of one crude sample formed higher acid sludge in comparison to its crude oil. For acid solutions containing 3000 ppm of ferric ion, the emulsion stability increased for all crude oil and maltene samples. Moreover, the stability of some maltene emulsions increased to 48% and 100% in the presence of 3000 ppm of ferric ions. The presence of ferric ions caused forming very stable emulsions, while most of the sludge formation took place at higher pH values. Finally, it was also attained that emulsion and sludge formations could happen simultaneously.

酸处理可能导致稳定的盐酸-原油乳状液及其后续污泥的形成，对石油生产产生不利影响。在这个过程中一个主要的歧义是辨别原油中对形成的乳剂稳定性影响最大的成分。这个基本问题在以前的研究中没有得到充分的解决。本文分别研究了原油脱沥青部分（maltene）对酸致乳化液和油泥的影响。在不同铁离子浓度和酸性pH值条件下，比较了4种原油及其maltene样品的乳化液相分离和形成污泥量。相分离的结果，作为乳状液稳定性的判据，表明原油样品形成的乳状液比空白盐酸下的麦芽烯样品稳定6% ~ 25%。麦芽糖烯与废酸（pH = 2）的乳化液在乳化后15 min内完全破裂。此外，在空白HCl存在下，麦芽素成分对污泥形成的贡献通常较小。沥青质是与HCl相互作用的关键成分。然而，与原油相比，一种原油样品的麦芽烯形成了更高的酸泥。对于含有3000 ppm铁离子的酸溶液，所有原油和马氏烯样品的乳液稳定性都提高了。在3000 ppm铁离子的存在下，一些马氏烯乳液的稳定性提高到48%和100%。铁离子的存在导致形成非常稳定的乳剂，而大多数污泥的形成发生在较高的pH值。最后得出乳化液和污泥可以同时形成的结论。

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引用次数: 0

Occurrence state of lacustrine shale oil in the second member of the Paleogene Kongdian Formation, Cangdong Sag, Bohai Bay Basin 渤海湾盆地沧东凹陷古近系孔店组二段湖相页岩油赋存状态

IF 6.1 1区工程技术 Q2 ENERGY & FUELS

Petroleum Science

Pub Date : 2025-08-01 DOI: 10.1016/j.petsci.2025.07.001

Zhi-Hao Wang , Jian-Hua Zhao , Xian-Zheng Zhao , Ke-Yu Liu , Xiu-Gang Pu , Qin-Hong Hu , Wen-Zhong Han , Wei Zhang , Zhan-Nan Shi

Understanding the occurrence state of shale oil is crucial for the effective development of shale oil resources. Although the second member of the Kongdian Formation (Ek₂) is a key interval for lacustrine shale oil production in the Cangdong Sag, Bohai Bay Basin, the occurrence state and controlling factors of shale oil in this formation remain poorly understood. This study established a multi-step programmed pyrolysis, combined with a light hydrocarbon recovery scheme, to quantitatively characterize the shale oil in different occurrence states. An integrated approach utilizing Rock-Eval pyrolysis, pyrolysis-gas chromatography, and crude oil gas chromatography was employed. Factors influencing the shale oil occurrence state were analyzed from petrology and organic geochemistry perspectives. The study revealed significant variations of shale oil occurrence states within the Ek₂, attributed to differences in sedimentary organic matter, mineral compositions, sedimentary structures, and thermal maturity. Felsic laminae are the primary reservoir space for oil in laminated shales, and the frequent interbedding of felsic and organic-rich laminae facilitates the retention of free oil. The contents of free and adsorbed oil are primarily influenced by organic matter content and shale storage capacity, both of which exhibit distinct occurrence patterns. Based on the shale reservoir quality classification using the pyrolysis values of S_1-1 + S_1-2 and (S_1-1 + S_1-2) × 100/TOC, the Ek₂ shale demonstrates significant exploitation potential, with the first-level reservoirs comprising 66%, second-level reservoirs 11%, and third-level reservoirs 23%. These findings provide new insights into the geological accumulation and production of shale oil.

了解页岩油赋存状态对页岩油资源的有效开发至关重要。孔二段（Ek2）是渤海湾盆地沧东凹陷湖相页岩油的关键产层，但对该组页岩油赋存状态及控制因素的认识尚不清楚。本研究建立了多步程控热解结合轻烃采出方案，对不同赋存状态下的页岩油进行了定量表征。采用岩石热解、热解-气相色谱和原油气相色谱相结合的方法。从岩石学和有机地球化学角度分析了影响页岩油赋存状态的因素。研究表明，由于沉积有机质、矿物组成、沉积构造和热成熟度的差异，Ek2区内页岩油赋存状态存在显著差异。长英质纹层是层状页岩原油的主要储集空间，长英质纹层与富有机质纹层的频繁互层作用有利于游离油的滞留。游离油和吸附油的含量主要受有机质含量和页岩储气容量的影响，两者具有明显的赋存规律。根据S1-1 + S1-2和（S1-1 + S1-2） × 100/TOC的热解值进行页岩储层质量分类，发现Ek2页岩具有较好的开发潜力，其中一级储层占66%，二级储层占11%，三级储层占23%。这些发现为页岩油的地质聚集和生产提供了新的见解。

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引用次数: 0