镶嵌暂堵钻井液在潘河区块15~#煤层开采试验中的应用

Application of Mosaic Temporary Plugging Drilling Fluid for CBM Development in 15~# Coal Seam of Panhe Block

潘河15~#煤层含气量大,易碎易污染,井壁坍塌严重。分析其坍塌与煤储层保护的机理,采用镶嵌暂堵钻井液进行了研究试验。结果表明,该钻井液具有良好的流变性,API失水低于10 m L,井壁防塌和储层保护效果良好,9口井的平均煤层井径扩大率6.13%,试验井先期产量达2 112 m^3/d,均优于清水钻进。形成了一套适宜潘河15~#煤开发的钻井液体系,并为解决井壁坍塌和煤储层保护难题提供了新的思路。

There is rich CBM resources in 15# coal of Panhe block. But the coal is fragile and easy to be polluted, and the well sidewall collapsing is serious. The mechanism of weU wall collapsing and coal reservoir protection have been studied. The mosaic temporary plugging drilling fluid is used to research and drill well. The result showed that the API filtration loss of the mosaic temporary plugging drilling fluid was less than 10 mL, and its rheological property is good. It is concluded that the fluid has the capability of prevent borehole sloughing and protect coal reservoir. In the application of 9 wells, the coal well average diameter enlargement rate was only 6.13%. After the test well put into production, the early gas yield is 2 112 m3/d, the result is better than clear water drilling. The mosaic temporary plugging drilling fluid is conducive to Panhe block. More importantly,this drilling fluid provides a new solution for coal sloughing and reservoir protection.