安泽区块煤储层孔裂隙特征及水敏效应损害机理

发布时间：2019-03-06 21:05

【摘要】：针对水敏效应会引起煤储层渗透率伤害,造成储层渗透率降低,从而影响煤层气井产量的问题,研究了沁水盆地南部安泽区块煤储层物性特征、水敏感性损害程度以及该区煤储层水敏损害机理,对安泽区块山西组3号煤层煤样进行了扫描电镜观察、显微组分和矿物测定以及水敏感性试验。试验结果显示:安泽区块3号煤样品水敏损害率为29.92%~54.03%,平均43.53%,水敏损害程度介于弱敏感到中等偏强之间;水敏损害率与黏土矿物含量、液体流速呈正相关关系,与煤岩渗透率呈负相关关系;煤储层水敏效应存在2种损害机制,一是黏土矿物水化膨胀而引起的静态渗透率降低机制,二是由黏土矿物颗粒分散运移而造成的动态渗透率降低机制。
[Abstract]:In view of the problem that water sensitive effect can damage coal reservoir permeability and reduce reservoir permeability, which will affect the production of coal bed gas well, the physical properties of block coal reservoir in Anze district, southern Qinshui basin, are studied. The damage degree of water sensitivity and the mechanism of water sensitivity damage of coal reservoir in Anze block were observed by scanning electron microscope (SEM), micro-composition and mineral determination and water sensitivity test of coal samples of Shanxi formation No. 3 coal seam in Anze block. The experimental results show that the water sensitivity damage rate of No. 3 coal sample in Anze block is 29.92% / 54.03%, with an average of 43.53%, and the degree of water sensitivity damage is between medium and strong sensitivity. The water sensitive damage rate has a positive correlation with clay mineral content and liquid velocity, and a negative correlation with coal and rock permeability. There are two damage mechanisms for water sensitivity in coal reservoir, one is static permeability reduction caused by hydration and expansion of clay minerals, and the other is dynamic permeability reduction mechanism caused by dispersion of clay mineral particles.
【作者单位】：中国地质大学(北京)能源学院;中国地质大学(北京)煤层气国家工程中心煤储层实验室;
【基金】：国家自然科学基金资助项目(41530314) 高等学校博士学科点专项科研基金资助项目(20130022110010)
【分类号】：TE311

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