提高致密砂岩气藏压裂效果的定向射孔技术应用研究

Study on Application of Oriented Perforating in Improving Fracturing in Tight Sandstone Gas Reservoirs

由于致密砂岩气藏压裂时,普遍存在的地层高破裂压力和较大的近井筒效应,降低了水力压裂的效果,可能导致压裂施工的失败。根据理论分析,结合真三轴水力压裂模拟实验,得出平行于最大主应力方向定向射孔工艺有助于降低地层破裂压力及近井筒效应,提高压裂效果。基于降低地层破裂压力作用机理分析,对定向射孔与复合射孔等高能气体压裂类射孔工艺进行比较认为,在提高压裂效果的功效上,定向射孔更隹;基于理论分析,开展了以提高致密砂岩气藏压裂效果的定向射孔工艺现场试验,达到了有效降低试验井地层破裂压力及近井筒摩阻的目的,效果明显,为致密砂岩气藏高效压裂提供了新的思路。

Hydraulic fracturing is one of the major measures to improve the productivity in low permeability tight sandstone gas reservoirs,but it exist high fracturing pressure and near well bore effect for tight sandstone gas reservoirs during fracture.This declined hydraulic fracturing effect,even induced the failure of fracturing combining theoretical analysis with the true triaxial simulation test of hydraulic fracture,the results are obtained when orientation for perforating is parallel to the orientation of maximum principal stress,it will decline formation fracturing pressure,and decrease near well bore effect,and improve effect for hydraulic fracturing.Based on analysis the mechanism about declining deformation fracturing pressure,and carried on comparison studies about perforating technology between oriented perforating and compound perforating.It has been conclude that oriented perforating improve effect of fracturing.In order to improve fracturing effect in low permeability tight sandstone gas reservoirs,the author conducted field experiments of oriented perforating,it had decreased fracture pressure and near well bore friction for experiment well.It provides new clue to high efficiency fracture in tight sandstone gas reservoirs.