支撑剂嵌入不同坚固性煤岩导流能力实验研究

Experimental research on flow conductivity of different firmness coal rock embedded by proppant

煤层气井压裂过程中,支撑剂嵌入会影响支撑裂缝的导流能力,从而严重影响煤层气的开发。为了研究支撑剂嵌入不同坚固性煤岩程度及支撑裂缝导流能力,测定了典型矿区煤岩的坚固性系数,运用LD-1A导流能力测试系统进行了支撑剂嵌入不同煤岩及导流能力模拟实验。实验表明,端氏、龙门塔和寨崖底煤岩的坚固性系数分别为1.4、0.4和0.5,35 MPa时,支撑剂嵌入柳林龙门塔煤岩的深度为0.5 mm,嵌入对导流能力损害率可达40%;不同矿区煤岩的坚固性系数差异很大,坚固性系数越小,支撑剂嵌入煤岩越严重,导流能力损害程度越大。该研究可为现场压裂施工提供依据。

In the process of well fracturing for CBM formations, proppant embedment in coal rock can affect fracture flow conduc- tivity and the development of CBM. In order to study proppant embedment in different firmness coal rock and flow conductivity, the coal rock firmness coefficients in representative fields were measured. Proppant embedment and fracture flow conductivity experiments were conducted with LD-1A proppant conductivity testing system. The result shows that the firmness coefficients of Duanshi, Longmenta and Zhaiyadi coal rocks are 1.4, 0.4 and 0.5, the depth ofproppant embedment in Liulin Longmenta coal rock is 0.5 mm, and the degree of flow conductivity damage by proppant embedment can reach 40%, when the closure pressure is 35 MPa. The firmness coefficient of dif- ferent coal rock differs greatly. The smaller the firmness coefficient is, the deeper the proppant embedment in the coal rock will be, and the greater the degree of fracture flow conductivity damage will be. With the experimental data and production experience, the study has some reference for fracturing practice in field.