吉林两井地区低残渣缔合压裂液的研究与应用

The Study and Application of a Low Residue Associated Fracturing Fluid in Liangjing Area in Jilin Oilfield

两井地区储层为典型的低孔特低渗难采储藏,储层物性及孔喉结构差,而该油田常用的压裂液的残渣及破胶残液容易对天然裂缝、支撑裂缝及基质造成伤害,造成对储层的严重污染。分析了造成储层伤害的主要因素,提出了低伤害压裂液的性能要求,优选出了弱酸性高弹性缔合压裂液。对该缔合压裂液的耐温耐剪切、破胶及弹性力学性能的评价结果表明,冻胶黏弹性高,能携带高浓度的支撑剂,稠化剂无水不溶物,破胶后残渣含量低于52mg/L,破胶黏度低于3mPa.s。通过配套技术的应用、优化泵注工序及压后管理,该缔合压裂液现场应用4口井8层,见到了好的效果,满足了储层低伤害改造的需求,且该压裂液现场配制简单、性能可控、成本低。

The reservoir formations in Liangjing area are characteristic of low porosity and ultra low permeability,and poor pore throat structures.Residues from fracturing fluids containing hydroxypropyl guar gum always caused damages to the natural fractures,propped fractures and the substrate in the reservoir formations.A requirement was presented on the property of fracturing fluids based on the analysis of reservoir damages,and a weak acid high elasticity associated fracturing fluid was formulated and optimized.Laboratory evaluation showed that this fracturing can carry high concentration of proppant.The thickening agent contained no water insolubles,and thus resulted in a residue content of less than 52 mg/L after the viscosity was broken to less than 3 mPa·s.This associated fracturing fluid has been used in 8 layers in 4 wells,and good results were obtained.