鄂尔多斯盆地大牛地气田盒1段储层应力敏感性及对水平井开发的影响  

Stress sensitivity of the 1^(st) Member of Xiashihezi Formation and its influences on horizontal well development of Daniudi gas field,Ordos Basin

作　　者：陈奎[1] 任广磊[1] 杨文娟[1] 于耀南 

机构地区：[1]中国石化华北油气分公司勘探开发研究院,河南郑州450006

出　　处：《石油与天然气地质》2016年第2期267-271,共5页Oil & Gas Geology

基　　金：国家科技重大专项(2011ZX05045)

摘　　要：大牛地气田二叠系下石盒子组1段(盒1段)是典型的低渗透储层。为明确储层的应力敏感性,选取了不同类型的13块岩心开展了应力敏感性实验。结果表明,盒1段岩心普遍存在应力敏感,且存在渗透率滞后现象,这说明随净应力的增加,岩样发生了塑性变形。采用内应力敏感指数法对实验数据进行分析,结果表明物性较好的Ⅰ类储层应力敏感性较弱,Ⅱ类、Ⅲ类储层为弱~中等,13块岩心的平均内应力敏感指数为0.086,整体评价应力敏感性为弱。建立了Ⅰ-Ⅲ类储层的多级压裂水平井数值模拟模型,并将储层无因次渗透率随地层压力的变化关系加入到模型中。在定气井产量的条件下,对比应力敏感对水平井开发的影响。数值模拟结果表明:对于Ⅰ类储层,应力敏感对稳产时间和稳产期产气量影响很小,仅降低1.6%;Ⅱ类储层影响较小,降低了11.2%;Ⅲ类储层则影响较大,降低了23.6%。因此应加强Ⅱ类、Ⅲ类储层气井的配产研究和生产管理,保证开发效果。The 1stMember of Xiashihezi Formation（ H1） of Daniudi gas field is a typical low permeability reservoir in Ordos Basin. In order to clearly understand the stress sensitivity of H1,13 core samples of different types were chosen for stress sensitivity tests. The experimental results show that the core samples from H1 commonly show stress sensitivity and permeability hysteresis,indicating that the cores experience plastic deformation with the increasing of net stress. Analysis of the experimental data with internal stress sensitivity index method shows that the type Ⅰ reservoirs with better physical properties has a relatively low stress sensitivity,while the type Ⅱ and Ⅲ reservoirs have low to moderate stress sensitivity. The averaged internal stress sensitivity index of these 13 core samples is 0. 086,indicating that the overall stress sensitivity is low. We built numerical simulation models of multi-stage fracturing of horizontal wells for Ⅰ- Ⅲ type reservoirs,into which the relationship between dimensionless permeability and the formation pressure was incorporated. Under a constant gas production rate scheme in the numerical model,the effects of stress sensitivity on horizontal well performance were investigated. The numerical simulation results show that the stress sensitivity has very little effect on gas rate during stable production period for type Ⅰ reservoir,which only decreased by 1. 6% in comparison with that without stress sensitivity case. For type Ⅱ and Ⅲ reservoirs,the gas rate during stable production period decreased by 11. 2% and23. 6%,respectively. Therefore,production allocation and management should be strengthened for type Ⅱ and Ⅲ reservoirs to guarantee well performance.

关 键 词：应力敏感 低渗透 水平井 气田开发 大牛地气田 鄂尔多斯盆地 

分 类 号：TE37[石油与天然气工程—油气田开发工程]