定北区块复杂储层压裂工艺技术研究与应用

Research and Application of Fracturing Technology in Complex Reservoir of North-Dingbian Block

定北区块上古生界储层具有低孔、致密、高温、天然裂缝发育、基本无自然产能等复杂特征。勘探前期因地层参数缺乏,采用常规硼交联压裂液体系及常规压裂技术实施作业,压裂工艺的针对性不强,施工过程中极易出现砂堵现象。为此,开展了高温暂堵压裂液体系及测试压裂工艺技术应用研究,研制了有机锆交联高温暂堵压裂液体系,并选择定北7井2储层首先开展了小型压裂测试,获取了储层、压裂裂缝、压裂液等相关参数。根据测试压裂结果,对该储层进行压裂设计与施工:设计排量4.5m3/min,前置液比例37%,平均砂比24%,加砂量38m3,全程使用有机锆交联高温压裂液,前置液添加1%屏蔽暂堵剂。压裂施工结束后,对主压裂数据进行压力拟合,结果显示,研制的高温暂堵压裂液体系能满足区块高温、微裂缝发育储层的压裂造缝、携砂等施工需要,压裂改造达到了预期效果。

The reservoir in upper Paleozoic of North- Dingbian block has the characteristics of low porosity, tight,high temperature,natural fracture and low natural production.Common boron cross-linked fracturing fluid system and conventional fracturing technology were applied at early time ,which will result in sand trouble for lacking reservoir parameter.So the application of high-temperature and temporary blocking fracturing fluid sys- tem and testing fracturing technology were researched. Organic zirconium cross-linking fracturing fluid system with temporary blocking at high temperature was developed and small-scale fracturing test was carried out in No.2 reservoir of well Dingbei 7.The parameters of reservoir,fracture,and fluid have been obtained.According to the testing results,the fracturing technology is designed and operated in the reservoir.Discharge capacity is designed as 4.5m3/min and proportion of the ahead fluid will be 37%.Average proppant concentration is 24% and gravel input is 38m3.The organic zirconium cross-linking fracturing fluid with temporary blocking at high temperature will be applied during the whole process.Shield temporary blocking agent of 1% will be added in the ahead fluid.After the fracturing,major fracturing data is matched on pressure.The result presents that the developed fracturing fluid system can meet the demands of width generation and proppant carrying in the reservoirs of microfracture at high temperature.It achieved the desired effect.