川西深层气藏岩石应力敏感特征及对产能影响  

ROCK STRESS-SENSITIVITY IN WEST-SICHUAN DEEP GAS RESERVOIR AND ITS IMPACT ON PRODUCTIVITY

作　　者：单钰铭[1] 童凯军[1] 黄敏[2] 李勇[3] 

机构地区：[1]成都理工大学“油气藏地质及开发工程”国家重点实验室,四川成都610059 [2]西南油气分公司工程技术研究院,四川德阳618000 [3]中国石化石油工程西南有限公司钻井工程研究院,四川德阳618000

出　　处：《大庆石油地质与开发》2009年第3期49-54,共6页Petroleum Geology & Oilfield Development in Daqing

摘　　要：为了解致密砂岩储层生产过程中有效覆压变化对渗透率的影响特点，在不同有效覆压水平下，进行了致密砂岩岩样渗透率实验。实验结果表明：致密砂岩岩样的渗透率随有效应力的增加而减小，但减小趋势中存在一个拐点区间，拐点区间前渗透率随有效覆压的增加下降幅度较大，拐点区间之后则下降幅度趋于平缓。压力恢复实验则显示了岩石由于部分塑性变形导致的应力敏感伤害成为一种永久的、不可逆的伤害。通过对实验数据进行拟合分析，建立起了有效覆压与渗透率之间的乘幂式关系。在平面径向流假设条件的基础上，考虑储集层应力敏感性影响，推导出了新的产能方程，定量计算分析了应力敏感对气井产能的影响，对深入研究川西地区致密砂岩气藏开发动态和气田配产方案具有一定的指导意义。In order to understand influence of effective follow-up pressure change on permeability in the production process of tight sandstone reservoir, a permeability experiment of tight sandstone rock sample is performed at different levels of effective folIow-up pressure. Experimental results show that permeability of tight sandstone rock sample reduces with the increase of effective stress, but there is inflection point range in the decreasing trend, where permeability ＂drops larger before the inflection point range, but then tends to be slow after it. An experiment of pressure to resume shows the pressure-sensitive harm on the rock resulted from some plastic deformation, will be permanent and irreversible. By matched analysis on experimental data, the power relationship between effective follow-up pressure and permeability is established, Based on the assumption of radial fluid flow, considering sensitivity of reservoir stress effects, a new productivity equation offering quantitative analysis on effect of stress-sensitivity on gas well productivity is derived, which has guiding significance for further study on tight sandstone gas reservoir development and gas production allocation program in Western Sichuan area.

关 键 词：致密砂岩 有效覆压 渗透率 拐点区间 乘幂 产能方程 

分 类 号：TE321[石油与天然气工程—油气田开发工程]