基于数字散斑变形模拟实验的深部复杂断块应力场传递特征研究  

Stress field propagation characteristics of deep complex fault blocks based on digital speckle deformation simulation experiment

作　　者：冯建伟 郑晨曦 刘水珍 周重安 吴文柯 沈郅阳 FENG Jianwei;ZHENG Chenxi;LIU Shuizhen;ZHOU Chongan;WU Wenke;SHEN Zhiyang(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《石油实验地质》2024年第4期710-721,共12页Petroleum Geology & Experiment

基　　金：国家自然基金面上项目(42072234);中国石油重大科技项目(ZD2019-183-006)联合资助。

摘　　要：在油田勘探开发过程中,地应力研究在掌握深层油气的运聚规律、改善储层压裂效果和钻井工程风险评价等方面发挥着重要的作用。而前人对地应力的研究主要集中在二维/三维模拟方面,对区域构造变动和生产开发过程中的应力动态变化规律研究甚少。以渤海湾盆地南堡凹陷G区块为例,通过制作相似地质模型,设置边界条件并进行数字散斑变形动态模拟实验,基于LOESS局部回归分析方法,得到应力/应变在空间上的传播规律。结合经典的应力波理论认为,在构造力的持续作用下,地层中任一点的应力/应变随时间的变化呈现明显的旋回波动性,在断层附近这种旋回特征更加明显,且旋回幅度更大;应力波穿过断层发生多重反射、透射现象,众多左行波与右行波相遇造成局部应力和应变集中,从而呈现为高值区,穿过断层时应力波产生应变或变形,导致明显的能量衰减;随着时间的变化,应力/应变的总体传播方向具有选择性,其总是垂直于断裂带压实强、结构致密的方向,即透射过后会造成能量急剧衰减的方向;随着时间的变化,地层中任一点应力/应变的传播均呈现为波动旋回式,但应力波不同于声波,整体来看,应力/应变旋回曲线的最大幅度和最小幅度在空间上沿着作用力方向也呈现为波动式。In the process of oilfield exploration and development,the study of crustal stress plays an extremely important role in understanding the patterns of deep oil and gas migration and accumulation,enhancing reservoir fracturing efficiency and assessing drilling engineering risks.Previous studies on crustal stress have mainly focused on 2D/3D simulations,with very little research on regional structural changes and stress dynamic changes in the process of production and development.Taking block G of the Nanpu Sag of Bohai Bay Basin as an example,by creating similar geological models,setting boundary conditions,and conducting digital speckle deformation dynamic simulation experiment,the spatial propagation characteristics of stress/strain were obtained using the LOESS local regression analysis method.Combined with the classical stress wave theory,it was concluded that under the continuous action of tectonic force,the change of stress/strain at any point in the layer over time shows obvious cyclic volatility.This cyclic characteristic is more evident near the fault,with larger cyclic amplitude.Multiple reflections and trans⁃missions occur when the stress wave passes through the fault.When numerous leftgoing waves meet rightgoing waves,the local stress and strain are concentrated,forming high⁃value areas.When a stress wave passes through a fault,the resulting strain causes a significant energy attenuation.Over time,the direction of stress/strain propaga⁃tion is selective,always perpendicular to the direction of strong compaction and dense structure of the fault,leading to sharp energy decay after transmission.Over time,the propagation of stress/strain at any point in the formation appears as a wave cycle.However,unlike sound waves,the maximum and minimum amplitudes of the stress/strain cycle curve exhibit fluctuation characteristics along the direction of the applied force in space.

关 键 词：应力传播 数字散斑实验 复杂断块 旋回特征 应力波 南堡凹陷 渤海湾盆地 

分 类 号：TE135[石油与天然气工程—油气勘探]