酸压裂缝导流能力影响因素分析

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.

Influence factor analysis on acid pressure rips diversion capacity

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 hy...