伊川凹陷屯1井储层评价及压裂改造

通过对洛阳-伊川盆地伊川凹陷屯1井压裂层段的系统评价,分析认为该井压裂层段具有低孔、低渗、极低产特征。核磁测井有效孔隙度3.3%,渗透率0.645×10-3μm2;成像测井显示裂缝发育,测井评价是基质孔隙度+裂缝型储层。试油测试自然产气量仅53m3/d,测试二关井压力恢复数据定性分析认为裂缝较发育,基质孔隙渗透性极差,常规压裂改造增产效果差。应用非常规压裂技术基本方法对射孔方式、泵注管柱、施工规模、压裂参数进行优化,采用高排量、高液量、低粘度、低砂比的压裂方案,力争形成多缝、复杂裂缝,增加泄流面积。通过非常规压裂改造,10mm油嘴放喷,油压3.1～3.5MPa,日产气6600～7000m3,实现了河南外围洛阳-伊川盆地油气勘探的重要突破。

Reservoir evaluation and fracturing transformation of Tun 1 well in Yichuan sag

Through the systematical evaluation of Tun 1 well fracturing layer in Yichuan sag in Luoyang-Yichuan basin,it is thought this layer has the features of low porosity,low permeability,and extremely low yield.Nuclear magnetic logging effective porosity is 3.3%,permeability is 0.645×10-3μm2.Imaging logging indicates fracturing development,which is matrix porosity and fracturing reservoir.Oil testing shows the natural gas capacity is only 53 m3/d,Through secondary shut-in well pressure recovery data qualitative analysis,it is thought fracture developed,matrix porosity permeability is bad,using conventional fracturing transformation to increase yield is poor.In this paper,using fracturing technology to optimize perforation mode,pump string,construction scale,fracture parameters and adopting fracturing scheme of high emissions,high fluid volume,low viscosity,low sand ratio to form more fracture and complex fracture and increase discharge area.Through unconventional fracturing transformation,10 mm nozzle spray,hydraulic 3.1-3.5 MPa,daily gas capacity is 6600-7000 m3,which realize the important breakthrough for the oil and gas exploration of Luoyang-Yichaun basin.