摘要
Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well(hereinafter referred to as EYY2HF well).The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System,which is the oldest stratum of horizontal shale gas wells in the world.A total of 4341 microseismic fracturing events were identified,and 23 fracturing stages of the well were defined.The fluctuation of the number of events showed a repeating“high-low”pattern,and the average energy of these events showed minimal differences.These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate.The main body of the fracture network extended from northwest to southeast,consistent with the interpretation of regional geological and seismic data.The stimulated rock volumes showed a linear increase with the increase of the fracturing stage.Some technological measures,such as quick lift displacement,quick lift sand ratio,and pump stop for secondary sand addition,were adopted during fracturing to increase the complexity of the fracture network.Microseismic fracture monitoring of the well achieved expected eff ects and guided real-time fracturing operations and fracturing eff ect evaluation.
水力压裂技术是页岩气开发的重要手段,微地震监测是压裂效果评价的关键技术。位于鄂西地区的鄂阳页2HF井,其目的层为下震旦统陡山沱组二段,是世界上页岩气水平井完钻的最古老地层。为了评价该井在古老地层中水力压裂的效果,指导压裂施工,探索和优化鄂西地区压裂工艺,同时开展了水力压裂和微地震监测。完成23段井中微地震压裂监测,共识别、定位事件4341个,事件个数总体上呈现出“高-低”交替波动规律,事件平均能量差异不大。缝网主体发育呈北西-南东向两翼延伸,这与区域地质和地震资料解释吻合。储层改造体积表现出线性增加的特点。压裂过程中采取了快提排量、快提砂比、停泵二次加砂等工艺措施,增加了裂缝复杂程度。井中微地震压裂监测取得了理想的效果,指导了实时压裂和压裂效果评价。
基金
National key R&D plan(2016YFC060110605)
National major projects(2016ZX05034004-005)。
