浅层煤层气U型井分段压裂研究与应用

Research and application of staged fracturing technology of U type well in shallow coalbed methane

织金区块煤层气资源丰度高,但煤层具有多、薄、浅的特点。针对该特点的U型井完井方式,压裂施工面临轨迹位垂比大、管柱下入困难、滤失大、缝高失控等问题。以织2U1P井为例,开展了浅层煤层气U型井压裂管柱结构、射孔参数、裂缝参数、排量及施工规模的优化,优选低伤害、低成本的压裂液和支撑剂体系。织2U1P井分6段压裂,累计注入液量4 333.14 m^3,砂量294.45 m^3,最高砂比20%,压后获得4 500 m^3/d的高产。该井产能测试获得突破,证实了织金地区浅层煤储层的含气性能,同时对其它浅层煤层气开发方式也具有较好的借鉴意义。

Zhijin block has high abundance of coalbed methane（CBM） resource, and the coalbed has the characters of multiple, thin and shallow. According to well completion methods of U type well, fracturing construction occurs the problems of big true vertical depth ratio, difficulties of running string, large fluid loss and fracture height out of control. Take well Zhi-2U 1P for example, the optimization of fractured string structure, perforating parameters, fracture parameters, displacement and construction scale is con- ducted, fracture fluid of low damage and low cost and proppant are selected. Well Zhi-2U1P is divided to six sections of fractur- ing, and its cumulative fluid injection is 4 333.14 m3, sand content is 294.45 m3, highest proppant concentration is 20 % and after fracturing, the production is 4 500 m3/d. The breakthrough of productivity test verifies the gas bearing property of shallow coalbed in Zhijin block and provides better references for other shallow CBM development.