第39卷第1期 2018年2月
文章编号：10013873(2018)01008309
新疆石油地质
XINJIANG PETROLEUM GEOLOGY DO1:10.7657/XJPG20180111
Vol. 39,No.1 Feb.2018
玛湖凹陷百口泉组砂砾岩储集层岩石力学特征与
裂缝扩展机理刘向君，熊健"，梁利喜"，尤新才？
（1.西南石油大学油气藏地质及开发T程国家重点实验室，成都610500； 2.中国石油新疆油田分公司勘探开发研究院，新疆克拉玛依834000）
要：以玛湖凹陷百口泉组砂砾岩储集层为研究对象，通过岩石力学实验，开展了不同岩性砂砾岩储集层的岩石力搞
学特性和裂缝扩展机理研究。在此基础上，利用数值模拟方法构建含有真实砾石的二维模型，研究砂砾岩中裂缝扩展的过程，讨论了砾石强度对裂缝扩展机制的影响。研究结果表明：砂砾岩具有较强的非均质性，造成不同岩性的砂砾岩力学特性差异较明显，其中细砾岩的力学强度大于粗砾岩；岩石中砾石成分和基质成分间差异对砂砾岩力学特性的影响较大；单轴压缩中砂砾岩破坏模式主要以劈裂破坏为主，而三轴压缩中砂砾岩破坏模式包括裂破坏、单剪切破坏和双剪切破坏等；殊石颗粒对裂缝扩展存在屏藏作用，砂砾岩的破裂过程中裂缝扩展形式主要分为穿砾、绕砾、嵌入止砾等；砾石与基质强度差异增大，砾石屏蔽作用增强，裂缝遇砾石受阻增强，将造成裂缝遇到砾石的扩展由穿砾形式变为绕砾形式。
关键词：玛湖凹陷；百口泉组；砂砾岩储集层；常石力学特征；裂缝扩展机理
中图分类号：TE112.221
文献标识码：A
Rock Mechanical Characteristics and FracturePropagation Mechanismof Sandy Conglomerate
Reservoirs in Baikouquan Formation of Mahu Sag LIU Xiangjun', XIONG Jian', LIANG Lixi', YOU Xincai
(1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China; 2.Research Institute of Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China) Abstract: Taking the rock of the sandy conglomerate reservoirs of Baikouquan formation in Mahu sag as the study objects, the mechanical characteristics and fracture propagation mechanism of the sandy conglomerate reservoins with different lithologies are studied through vari-ous rock mechanical experiments, Based on which, a 2D model containing true gravels is established by using numerical modeling method, the dynamic process of fracture propagation in the sandy conglomerale are investigated, and the influence of gravel strength on fracture propagation mechanism is discussed. The results indicate that the sandy conglomerate are seriously heterogeneous, resulting in the obvious dfferences of mochanical characteristics in sandy conglomerates with different lithologies, among which the mechanical strength of fine conglomerate is higher than that of coarse conglomerate; the dferences between gravel and matrix compositions have significant influence on rock mechanical characteristics of the sandy conglomerate; the failure mode of the sandy conglomerate is dominated by splitting failure in uniaxial compression and by splitting failure, single shear failure and dual shear failure etc, in triaxial compression; gravel particles have shielding effect on the extension of fractures and the fracture propagation during rock failure process in the sandy conglomerate mainly con-tains 3 types such as going-through gravel, bypassing gravel and embedded in gravel. The strength of gravels and the matrix reflects the me chanical properties of glutenite, The larger the strength difference between gravel and matrix is, the stronger the shielding effect of the grav-els is, the stronger the received resistance of fracture wll be, causing that the fracture propagation would transfer from going-through gravel to bypassing gravel.
Keywords: Mahu sag; Baikouquan formation; sandy conglomerate reservoir, rock mechanical characteristic; fracture propagation mechanism
随着能源需要增加及勘探开发技术的进步，砂砾岩油气藏受到越来越多的关注"-。近年来，国内外发现了大量的砂砾岩油气藏，如准噶尔盆地西北缘地区、辽河油田西部凹陷、华北油田廊固凹陷、胜利油田东营凹陷和车镇凹陷等，其中准噶尔盆地西北缘地区
收稿日期：2017-1127
修订日期：20171205
基金项日：国家科技重大专项（2017ZX05070-001）
为冲积扇低孔低渗砂砾岩油气藏的主要分布区15-9 玛湖凹陷是准噶尔盆地六大生烃凹陷之一，也是盆地最具规模的油气聚集带与勘探区。随着勘探的深人，玛湖凹陷西斜坡下三叠统百口泉组(Tb)已成为重要的勘探开发层系0-"。玛湖凹陷百口泉组主要为冲积
作者简介：刘向书（1969-），女，四川资中人，教授，博士生导师，页气开发（T-l)15902855432(Email)liuxiangjumwpi@163.com 万方数据