低渗薄互层深层油气藏多层压裂工艺技术

Multilayer fracturing technology of deep low permeability thin interbed reservoir

中原油田薄互层油气资源埋藏深、物性差、井段长、纵向上存在"两薄"特征,早期大跨度合层压裂改造效果差,需要采用多层压裂改善压裂效果;针对薄互层多层压裂选层、控缝高、管柱安全等难题,通过建立多产层流量分配模型,模拟裂缝延伸状况,确定合层压裂跨度界限为15 m,建立控缝高需要隔层厚度图版,合理利用隔层厚度控制缝高,配套研发了可取式多层压裂管柱及系列工具,大大降低卡管柱风险,2013年1月至2015年12月现场应用40口井,成功率100%,有效率95%,累增油36 117.4 t、气2 244.45×104m3,平均单井日增油6.1 t、气0.26×104m3,取得了较好的压裂效果,实现了大跨度砂泥岩薄互层油气藏的有效动用。

Deeply buried thin interbed oil and gas resources of Zhongyuan oilfield, have special characteristics, such as, poor porosity and permeability, long well section, thin oil layer and interlayer on the longitudinal.Well production of using long-span layer fracturing is low,it need to use multilayer fracturing to improve the fracturing effect.Multilayer fracturing of thin interbed layers is difficult to selecte layers and control fracture height,after fracturing,pipe often pull out hardly.So,by creating productive layer flow distribution model, we can simulat fracture propagation,ultimately,we can make sure that the best fracturing span is 15 m.Meanwhile,a chart was made to select needed thickness of interlayer layer, we research and develop safe multilayer fracturing pipe to reduce the risk of pipe blocking.The technology was applied in 40 wells from 2013.1 to 2015.12 in Zhongyuan oilfield, the success rate was 100 %, effective rate was 95 %, cumulativet increased oil was 36 117.4 t, gas was2 244.45×10^4 m^3, average enhanced oil in single well was 6.1 t/d, gas was 0.26×10^4 m^3.