裂缝性油藏斜井水力裂缝破裂压力研究

摘要

Hydraulic fracturing technology has greatly improved reservoir recovery,and the key step of hydraulic fracturing technology is to accurately predict the fracture pressure of hydraulic fractures.The impact of the presence of natural fractures in fractured reservoirs,hydraulic fracture cracks will form more complex network in the near wellbore area,which makes the prediction of the breaking stress of hydraulic fracture is a difficult problem.Considering the 3 failure mode existence of hydraulic fractures in fractured reservoir,the stress distribution model based on the relative position of natural fractures and inclined perforation in the formation to study the wellbore and perforation,and establishes the calculation model of fracturing pressure of inclined shaft hydraulic fracture corresponding in different rupture mode.In Sichuan,a fractured reservoir X wells were analyzed,the calculation results show that the fracture pressure calculating rupture mode on hydraulic fracture model and fracture pressure size prediction is more accurate,it can be used for the design of hydraulic fracturing of fractured reservoir slope.%水力压裂技术在很大程度上提高了油藏采收率,水力压裂技术的核心步骤在于准确地预测水力裂缝的破裂压力.由于裂缝性油藏中存在着天然裂缝的影响,水力裂缝在近井地带区域会形成较为复杂的裂缝网络,这使得水力裂缝的破裂压力预测变得较为困难.考虑水力裂缝在裂缝性油藏中存在的3种破裂方式,依托天然裂缝与斜井射孔孔眼在地层中的相对位置来研究井筒与射孔孔眼的应力分布模型,并建立起在不同破裂方式下相对应的斜井水力裂缝破裂压力计算模型.对四川某裂缝性油藏的X井进行分析,计算结果表明,建立的破裂压力计算模型对水力裂缝的破裂方式和破裂压力大小的预测都较为准确,其结果可用于裂缝性油藏斜井的水力压裂设计.