伊通岔路河西北缘凝析气藏体积压裂技术研究与应用

伊通地堑岔路河断陷西北缘为低孔低渗致密凝析气藏,勘探主力储层埋藏深(2 000~4 000 m)、闭合应力梯度高(0.018~0.024 MPa/m)、温度高(95~150℃);储层伊蒙混层粘土矿物含量高,喉道细小;存在水敏、反凝析及"水锁"伤害,制约产能。常规压裂技术压后返排率低、产能低或无效果。采用复合压裂体积改造技术,通过高排量大液量低表界面、高防膨性能滑溜水造缝增加孔隙压力,提高地层能量同时形成复杂裂缝网络,降低水敏、水锁、反凝析现象,提高气体由基质向裂缝渗流的通道;并集成组合支撑、套管压裂等多项技术进行高排量大液量体积改造技术研究,现场应用2口井2层,施工成功率100%,压后返排率80%。

Research and Application of Volume Fracturing Technology in Yitong Chaluhe Northwest Margin Condensate Gas Reservoir

The reservoir in Yitong Diqian Chaluhe fault-sag northwestern margin belongs to low permeability and low pore condensate gas reservoir. The main exploration layers are deep （2 000～4 000 m）, high stress gradient （0.018～0.024 MPa/m） and high temperature （95～150 ℃）. The reservoir has high clay content with illite/smectite formation and fine throat, which lead to reservoir damage, especially water sensitivity, water lock and inverse condensation effect. The slick water is combined with cross-linked gel fracturing fluid to decrease damage to the reservoir, a large amount of slick water pumped with high pump rate will create fractures and increase the pore pressure, which can enhance the producing energy and create complex fracture nets at the same time. Therefore the water sensitivity, water lock and inverse condensation effect can be decreased to improve seepage channel of gas from matrix to fractures. This technology has been applied in 2 layers of 2 wells, treatment successful rates were 100%, the flowback rate achieved 80%.