酸压裂缝导流能力影响因素分析  

Influence factor analysis on acid pressure rips diversion capacity

作　　者：牟建业[1] 张士诚[1] 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249

出　　处：《油气地质与采收率》2011年第2期69-71,79,共4页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"大型油气田及煤层气开发"(2008ZX05017-003)

摘　　要：酸压是碳酸盐岩油气田大型增产改造的重要措施,酸压裂缝导流能力与酸蚀后裂缝表面的粗糙程度有关,不规则裂缝表面使酸压导流能力预测变得较为困难。酸压裂缝导流能力由裂缝表面形状、闭合应力和岩石力学性质决定,因而从裂缝粗糙表面形成机理角度研究了裂缝表面渗透率分布、岩性分布、温度和氢离子扩散系数对酸蚀裂缝导流能力的影响。通过建立中尺度酸压模型,模拟酸液在碳酸盐岩裂缝中的流动,分析酸液在裂缝表面与岩石的反应和裂缝表面形状随岩石溶解的变化,得到酸蚀裂缝的表面形状,然后计算裂缝导流能力。研究结果表明,酸蚀裂缝表面形状主要由油藏属性(渗透率和岩性在裂缝表面的空间分布)决定;闭合应力和岩石强度对酸压裂缝导流能力的影响与裂缝形状相关;酸蚀沟槽较宽时,较小的闭合应力能使沟槽闭合;局部非均质性使酸蚀沟槽在较高应力下保持张开,宏观非均质性使沟槽相互连接形成贯穿裂缝的沟槽。Acid fracturing is an important treatment of improving production in the carbonate oil field. The capacity of acid fracturing rips diversion is related with the level of acid erode rip surface, and the irregular rip surface makes the acid fracturing rips diversion difficult. The capacity is determined by the form of rip surface, close stress and the rock mechanical property. So, in view of the shape of rip surface, we study the spread of permeability in the rip surface, lithology spread, temperature, the hydrion diffuse ratio, and the acid erode rips diversion capacity. Based on the medium scale acid fracturing model, the simulation of the acid liquid running in the carbonate rocks rip, and analysis on the reaction which the acid liquid makes in the rock rip surface and the rip surface changing with the rock dissolution, we can get the form of acid erode rip surface, moreover, the rip diversion capacity can be calculated. The study result shows that the form of acid erode rip surface is determined by the reservoir property (permeability and the space spread of lithology in the rip surface). The effect of closure stress and rock strength is related with the form of rips. When the acid erode groove is wide, the lower closure stress can make it close; the local anisotropy makes acid erode groove open in higher stress, the macroscopic anisotropy makes the grooves connect to a penetrated rip groove.

关 键 词：酸压 裂缝导流能力 裂缝表面形状 岩石力学性质 闭合应力 

分 类 号：TE357.2[石油与天然气工程—油气田开发工程]