密切割分段压裂工艺在深层页岩气Zi2井的应用

深层页岩储集层高温、高地应力、高水平应力差特征明显,常规分段压裂后,储集层改造体积偏低,裂缝复杂程度偏低,气井测试产量偏低。主要原因是,深层页岩气井压裂施工期间高泵注压力、低施工排量在常规分段参数条件下不利于提高裂缝复杂程度,导致簇间储量动用不充分。为提高工艺技术适用性及储集层改造效果,开展了深层页岩气压裂工艺优化研究,结果表明,密切割分段压裂工艺有利于增加簇间应力干扰,提高裂缝复杂程度,提升簇间资源动用效率。Zi2井初期采用常规分段压裂工艺,在压裂设计指标执行率较低的情况下,开展了密切割分段压裂工艺现场试验,裂缝复杂程度及单井储集层改造体积提升明显,证明了密切割分段压裂工艺在研究区深层页岩气井中的适用性。

Application of Intensive Staged Fracturing Technology in Deep Shale Gas Well Zi-2

Deep shale reservoirs are characterized by high temperature,high in-situ stress and large horizontal stress difference.After the implementation of conventional staged fracturing,the stimulated reservoir volume is usually relatively small,the level of fracture complexity and the test yield of gas wells are low.It is concluded that high pump injection pressure and low flow rate during the staged fracturing are the main reasons leading to insufficient reservoir stimulation in deep shale gas wells.To improve the adaptability of the technology and the effect of reservoir stimulation,the study on fracturing optimization for deep shale gas is carried out.The simulation results show that the intensive staged fracturing is good for increasing stress interference between clusters and improving both fracture complexity and stimulated reservoir volume.The conventional staged fracturing technology was initially adopted in the Well Zi-2,and then a field test for intensive staged fracturing was carried out.The test results show that the fracture complexity and stimulated reservoir volume are significantly improved,indicating the applicability of the intensive staged fracturing technology in the deep shale gas wells in the study area.