页岩气层关键参数评价及射孔压裂优化选层

Evaluation on Key Parameters and Optimization Selection of Target Perforating and Fracturing Layer of Shale Gas Reservoir

针对四川盆地海相页岩气藏,以岩心分析为基础,综合利用钻井、测井、录井、地质、试气、岩心等资料,构建有机碳含量(TOC)、孔隙度(POR)、含气量(GAS)、脆性指数(BI)、破裂压力(PF)等页岩气层关键参数评价模型,依次优先考虑TOC、POR、GAS和BI四参数,分区块建立了页岩气测井解释标准,提出了页岩水平井射孔-压裂优选层原则。在四川盆地两个国家页岩气示范区应用30口井,页岩气层关键参数相对误差最大为7.6%,页岩气层测井识别正确率达95.0%,有力驱动了我国南方页岩气的勘探开发。

The work is carried out in marine sedimentary shale gas reservoirs in Sichuan Basin.Based on core analysis,comprehensively combining with drilling,logging,geology,gas testing and core data,an evaluation model which takes organic carbon content(TOC),porosity(POR),gas content(GAS),brittleness index(BI),fracture pressure(PF)as key parameters of shale gas reservoirs is established.This paper preferentially takes TOC,POR,GAS and BI as parameters,establishing different log interpretation standards in different blocks,suggesting some principles of optimizing preferred perforating and fracturing layers of horizontal wells in shale gas reservoir.The model is applied in thirty wells of two national shale gas demonstration zones in Sichuan Basin.The results turned out that the maximum relative error of shale gas reservoir′s key parameters is 7.6%and the accuracy of shale gas reservoir logging identification is 95.0%.This suggests the model strongly promotes the exploration and development of shale gas in southern China.