提高煤岩渗透性的酸化处理室内研究

对沁水盆地南部晋城矿区3号煤储层井下观察研究后,采集了含有方解石脉的煤岩样品,实验室条件下钻取了?25 mm的煤岩芯,利用两种不同的酸液体系对其进行了酸处理,并对酸化前后煤岩芯的渗透率、孔隙度及孔隙结构进行了测试和分析。结果显示,用盐酸对煤岩芯进行处理后,煤岩芯渗透率由原来的不足10-15m2增加到了20×10-15m2左右,孔隙度增加了4.654%,酸化主要通过改造1μm前后的孔、裂隙系统来提高煤渗透性。在此基础上,提出了对煤储层进行酸化处理在我国煤层气钻完井和增产改造中的应用前景。

Indoor study on acidification for enhancing the permeability of coal

After the research of No.3 coal reservoir in Jincheng area of Qinshui Basin，some coal samples were collected and drilled to be several 25 mm coal cores.Then，the coal cores are processed with two kinds of acids.The tests and analyses of permeability，porosity，and pores structure show that when the coal cores are processed with HCl acid，the permeability increases from less than 10-15 m2 to about 20×10-15 m2，and the porosity increases by 4.654%.Acidification enhances the permeability of coal cores by stimulating the pores or cracks of 1 μm before and after.On this basis，the acidification application prospects were put forward in the drilling/completion and production stimulation of Chinese coalbed methane wells.