深层高压低渗透储层应力敏感性研究

Stress sensitivity of deep-buried high pressure low permeability reservoirs

 聂法健¹ 田巍 2 国殿斌¹ 李中超¹

中国石化中原油田分公司勘探开发研究院，河南 濮阳 457001 中国石化中原油田博士后科研工作站，河南 郑州 450017）

Research Institute of Exploration and Development, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China Postdoctoral Research Workstation, Zhongyuan Oilfield Company, SINOPEC, Zhengzhou 450017, China)

 为了深入研究深层高压低渗透储层的应力敏感性，文中采用了回压应力敏感评价测试方法对储层进行评价，并分析了应力敏感性对产能的影响。研究表明：随着回压降低，渗透率先是急剧降低而后降低幅度越来越缓；应力敏感曲线分为2个阶段，第1阶段渗透率下降幅度较大，超过了45.00%，以微裂缝受压闭合和大孔隙被压缩的拟塑性变形为主，第2阶段渗透率下降幅度低于15.00%，以岩石骨架颗粒本体被压缩的弹性形变为主；应用整个应力敏感曲线来评价储层会夸大储层敏感性，应用第2阶段来评价储层的应力敏感性更符合实际情况。应力敏感性对产能的影响较大，研究区日产量下降率达到了4.57%，因此，油田现场要适时地采取措施防止应力敏感的发生。

 In order to further study the stress sensitivity of deep-buried high pressure low permeability reservoirs, the method of back-pressure stress sensitivity was used to evaluate the target reservoir, and the relationship between stress sensitivity and productivity was analyzed. Study shows that, with the back pressure reducing, the permeability first declines rapidly and then declines more and more slowly; the stress sensitivity curve is divided into two stages, the permeability of the first stage falling even more than 45.00%, mainly occurring pseudo plastic deformation of micro-cracks closure and big pores compressed under pressure; the permeability falling range of the second stage is less than 15.00%, mainly occurring elastic deformation of compressed rock skeleton body; the reservoir stress sensitivity is always exaggerated when the entire curve of stress sensitivity is used to evaluate the real reservoir; however, it is more accordant with the stress sensitivity of the real reservoirs to use the second stage of the stress sensitivity curve. The reservoir stress sensitivity has much influence on productivity, and the decline rate of daily productivity reaches 4.57%. Based on the above analysis, it is necessary to take proper measures to prevent the occurrence of reservoir stress sensitivity.

10.6056/dkyqt201606021