摘要
为了解鄂尔多斯盆地延川南区块煤层气井高产水的成因及高产水对煤层气井产能的影响,对延川南区块内煤层气的地质条件、压裂施工情况以及不同产水量煤层气井生产特征进行了分析研究,探讨了延川南区块高产水特征形成的原因,确定了高产水煤层气井的排采方法。结果表明,压裂缝的缝高过大,沟通了二叠系下统下石盒子组砂岩裂隙含水层组,是导致延川南部分煤层气井产水量过大的主要原因;高产水会造成实际见气储层压力比临界解吸压力低,降低了煤层气井产能。高产水煤层气井的排采难度大,需要选择合理的排采设备,在气井产气之前井底流压要平稳、快速下降,使煤层气井尽早见气,见气之后适当放缓排采速度。该排采方法在高产水煤层气井进行了应用,排采效果较好。
In order to determine the causes of high water yield in CBM（coalbed methane）wells in Yanchuannan Block of Ordos basin and its impact on the productivity of CBM wells, the geologic conditions, fracturing operation and production performance of CBM wells with different water yield in Yanchuannan Block were analyzed, the cause of water formation was discussed, and draining method for high water yield wells was proposed. The results show that excessive fracture height connecting the fractured sandstone aquifer in Lower Permian Xiashihezi Formation is the key factor of causing high water yield in some CBM wells in Yanchuannan Block; high water yield would lead to gas reservoir pressure lower than the critical desorption pressure, and decrease in the productivity of CBM wells. In addition,high water yield would pose challenge to drainage which requires selection of proper equipment. At first, the wells with high water yield should be drained to allow even and fast drop of bottom hole flowing pressure and early gas production, the speed of drainage may be slowed down properly after gas appearance. The application of this strategy achieved good effect, providing a new technical support for CBM wells with high water yield.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2013年第6期95-99,共5页
Petroleum Drilling Techniques
基金
中国石化科技攻关项目"延川南煤层气开发应用基础及关键技术研究"(编号:P11092)部分研究内容
关键词
煤层气
高产水
形成原理
产能影响
排采方法
延川南区块
coalbed methane
high water yield
formation principle
influence on productivity
drainage and pro- duction method
Yanchuannan Block
