Response to the paper by H. Zia,B. Lecampion “Explicit versus implicit front advancing schemes for the simulation of hydraulic fracture growth” (Int. J. Numer. Anal. Methods Geomech., 2019, 43 (6), 1300–1315)     

Aleksandr Linkov 《国际地质力学数值与分析法杂志》2020,44(16):2254-2259

The response presents three comments, which (i) explain theoretical background for the success of the explicit front advancing scheme by Zia and Lecampion (comment 1), (ii) suggest possible extensions (comment 2), and (iii) pay attention on expected limitations of the scheme to be checked by the authors in numerical experiments (comment 3). The response does not intend to present novel results: it is entirely based on known results published in the references cited.  相似文献   

Responses of chemically active and naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure          下载免费PDF全文

Chao Liu  Son K. Hoang  Younane N. Abousleiman 《国际地质力学数值与分析法杂志》2018,42(1):34-69

In this paper, the analytical dual‐porosity dual‐permeability poromechanics solution for saturated cylinders is extended to account for electrokinetic effects and material transverse isotropy, which simulate the responses of chemically active naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure. The solution addresses the stresses, fracture pore pressure, matrix pore pressure, fluid fluxes, ion concentration evolution, and displacements due to the applied stress, pore pressure, and solute concentration difference between the sample and the circulation fluid. The presented solution will not only help validate numerical simulations but also assist in calibrating and interpreting laboratory results on dual‐porosity dual‐permeability shale. It is recommended that the analytical solutions of radial and axial displacements be used to match the corresponding laboratory‐recorded data to determine shale dual permeability and chemo‐electrical parameters including membrane coefficient, ions diffusion coefficients, and electro‐osmotic permeability.  相似文献   

非均匀各向异性储层地震AVAZ响应模拟及分析     

韩旭  郭智奇  徐聪  刘财  刘喜武  刘宇巍 《世界地质》2018,37(2):608-619

基于波动理论的各向异性反射率方法能够充分考虑地震波动力学特征。对单界面理论模型、实际非均匀各向异性模型分别进行正演模拟及分析,比较Ruger理论与反射率方法模拟结果的波动力学特征。结果表明,对于界面模型两种方法均能得到相同的计算结果,但对于实际非均匀各向异性介质,基于Ruger理论的算法受时间采样率的影响,而基于波动理论的反射率方法输入实际空间域模型,计算结果不受时间采样率的限制。  相似文献   

鄂尔多斯盆地南部延长组长7油组页岩层系天然裂缝发育特征及主控因素     

李彦录  陆诗磊  夏东领  吕文雅  梁丰  唐磊  李睿琦  王磊飞 《地质科学》2022,57(1):73-87

利用地表露头、岩心、薄片和测井资料,对鄂尔多斯盆地南部长7油层组陆相页岩层系天然裂缝的成因类型、发育特征和主控因素进行研究。按地质成因,鄂尔多斯盆地南部长7油层组页岩层系的天然裂缝可以分为构造裂缝和成岩裂缝两大类,其中构造裂缝主要包括剪切裂缝和张性裂缝;成岩裂缝主要包括层理缝、页理缝和收缩裂缝。不同岩性中的天然裂缝发育情况明显不同,致密砂岩中以构造裂缝为主,层理缝仅在粉砂岩和局部细砂岩中发育;页岩和凝灰岩中页理缝、层理缝和构造裂缝均比较发育。不同类型的天然裂缝主控因素明显不同,构造裂缝的发育主要受岩性和岩石力学层层厚控制;砂岩中层理缝的发育主要受碳质纹层、粘土矿物转化程度等因素控制;凝灰岩中层理缝的发育主要受刚性玻屑脱玻化作用的控制;页岩中页理缝的发育主要受纹层、TOC含量和黄铁矿含量的控制。  相似文献   

塔北隆起X型走滑断裂成因机制的新解释     

黄少英  宋兴国  罗彩明  能源  马小丹  漆家福  陈石 《现代地质》2021,35(6):1797-1808

塔里木盆地塔北隆起发育两组呈小角度相交(40°)的透入性X型走滑断裂,分别沿着NNE走向和NNW延伸。在对塔北哈拉哈塘地区三维地震资料解释的基础上,对走滑断层的几何展布特征以及断层的剖面变形特征进行研究;同时重点解析了RP6断裂和HA13断裂,分析比较NNW向与NNE向断层的变形及发育特征差异;结合盆地重磁资料以及周缘造山带的活动特征,对塔北隆起小角度的X型走滑断层的发育机制以及演化进行了分析。研究表明,塔北隆起走滑断层在垂向上具有明显的分层变形特征,分为三个构造层:震旦系-中寒武统下构造层(TH₃界面以下)、上寒武统-中奥陶统中构造层(TH₃-TO₃t界面)和上奥陶统-石炭系上构造层(TO₃t-TP界面)。断层在下构造层和中构造层中整体处于压扭环境,多发育正花状构造;上构造层中断层主要发育负花状构造或正断层,整体处于张扭环境。两组断裂比较,NNW向断裂活动性强,在各构造层中均有显著的断裂特征发育,垂向连通性强,发育先存基底断裂,而NE向断层主要发育在中构造层,在下构造层和上构造层中断层发育不明显。活动性分析表明,断层的形成与演化具有多期性,走滑断层的形成经历了三期主要活动:中寒武世末、中晚奥陶世和志留纪-石炭纪。塔北隆起X型走滑断裂的形成受到了NNW向基底断裂和薄弱带的控制,NNW向先存基底断裂带或薄弱带优先发育走滑断裂,基底断裂与主挤压应力方向的夹角小于45°-Φ/2,NNE断层的发育受NNW向先存断裂限制,最终形成小角度相交的X型断裂。  相似文献   

Geometry and kinematics of brittle deformation in the Central Cameroon Shear Zone (Kékem area): Implication for gold exploration within the Central Africa Fold Belt in Cameroon     

《China Geology》2021,4(2):245-255

The Central Africa Fold Belt (CAFB) is a collision belt endowed with gold deposits in Eastern Cameroon area mined for about 50 years. However, favorable areas for gold exploration are poorly known. This paper presents (1) the kinematics of the brittle deformation in the Kékem area in the SW portion of the Central Cameroon Shear Zone and (2) constraints gold mineralization events with respect to the collisional evolution of the CAFB. The authors interpret that the conjugate ENE to E and NNW to NW trending lineament corresponds to the synthetic (R) and the antithetic (R’) shears, which accompanied the dextral slip along the NE to ENE striking shear. The latter coincides with the last 570–552 Ma D₃ dextral simple shear-dominated transpression, which is parallel to the Bétaré Oya shear zone hosting gold deposits. Gold mineralizations, which mainly occurred during the last dextral shearing, are disseminated within quartz veins associated to Riedel’s previous structures reactivated due to late collisional activities of the CAFB as brittle deformation. Gold mineralizations occurred mainly during the 570–552 Ma D₃ event. The reactivation, which might be due to dextral simple shear during mylonitzation, plausibly remobilized the early gold deposits hosted in syn-compressional rocks and/or possibly focused deep-sourced fluid mixed with those released by dehydration. Therefore, the Central Cameroon Shear Zone where Kékem is located, and which shows similar petrographical and structural features to those controling Batouri gold district, is a target area for gold exploration in Cameroon.  相似文献   

基于共轭梯度搜索的病态问题处理方法     

刘杰  张娟娟 《大地测量与地球动力学》2019,39(8):863-868

在最小二乘平差准则基础上，把病态平差问题转化为无约束的二次规划问题，并利用优化理论分析病态对平差解的影响。通过共轭梯度搜索算法在可行域中寻找最优步长因子，自动寻找最速下降方向，并给出迭代初值的设置方法。分析近似计算中病态问题与局部最优解的关系，讨论局部最优解的快速迭代方法，并通过实例验证算法的有效性，计算迭代的速度。由于整个过程没有对法方程系数矩阵进行求逆计算，该算法可用于处理大规模系数矩阵高病态的平差问题。  相似文献   

Anisotropic damage of rock joints during cyclic loading: constitutive framework and numerical integration     

Joshua A. White 《国际地质力学数值与分析法杂志》2014,38(10):1036-1057

This work describes a constitutive framework for modeling the behavior of rough joints under cyclic loading. Particular attention is paid to the intrinsic links between dilatancy, surface degradation, and mobilized shear strength. The framework also accounts for the important effect of shear‐induced anisotropy. The resulting approach is fully three‐dimensional and is not restricted to plane‐displacement kinematics. Both the governing formulation and an algorithm for implicit numerical integration are presented. While the proposed methods are general, we also postulate a specific model that is compared with experimental data. It employs relatively few free parameters but shows good agreement with laboratory tests. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Reply to comments on “Explicit versus implicit front advancing schemes for the simulation of hydraulic fracture growth” (Int. J. Numer. Anal. Methods Geomech., 2019, 43 (6), 1300–1315)” by Prof. Linkov     

Haseeb Zia  Brice Lecampion 《国际地质力学数值与分析法杂志》2020,44(18):2524-2526

We reply to Prof. Linkov comments on our article entitled “Explicit versus implicit front advancing schemes for the simulation of hydraulic fracture growth” (Int. J. Numer. Anal. Methods Geomech., 2019, 43 (6), 1300–1315). We present additional results indicating that both the implicit and explicit front advancement schemes are robust even in the case of a large stress contrast.  相似文献   

天然裂缝影响下的花岗岩水力裂缝扩展数值模拟     

王璜  王贵玲  岳高凡  甘浩男 《地质学报》2020,94(7):2124-2130

水力压裂技术是成功实现干热岩资源开发利用的重要手段之一，数值模拟技术能够精准预测水力裂缝扩展。针对典型花岗岩，借助黏性单元法，分别模拟了致密花岗岩和天然裂缝存在情况下的水力裂缝扩展特征，得出以下结论：致密花岗岩的水力裂缝形态单一，天然裂缝的存在增加了压裂后裂缝的复杂性；致密花岗岩水力裂缝拓展主要分为憋压和拓展两个交替往复的阶段，当存在天然裂隙时，水力压裂过程会变得复杂；天然裂缝存在时，水力裂缝的缝长和缝宽分别为致密花岗岩的5. 7倍和1. 7倍；缝网的形成需要借助复杂的压裂工艺实现。研究结果可以为增强型地热系统(EGS)储层水力刺激工作提供理论支持。  相似文献