天然气勘探与开发2025，Vol.48Issue(4)：60-69,10.DOI:10.12055/gaskk.issn.1673-3177.2025.04.006
南川区块志留系孔隙压力预测新方法
A new method for Silurian pore pressure prediction,Nanchuan block,southeastern Sichuan Basin
摘要
Abstract
In order to accurately predict the pore pressure in the Lower Silurian Longmaxi Formation and its overlying strata of the Nanchuan block in the transform zone on the southeastern margin of the Sichuan Basin,to help prevent frequent complex failures such as lost circulation,borehole collapse and pipe sticking caused by the weak pressure bearing capacity and poor stability of the overlying Lower Silurian Hanjiadian-Xiaoheba Formations,a new method for predicting formation pore pressure was developed based on the poroelasticity.The results show that,(i)fundamentally,this method comprehensively considers the formation mechanism of Silurian pore pressure,endowing it with strong pertinence and adaptability;(ii)verification in multiple wells for the method demonstrates that the average error of the predicted equivalent densities of pore pressure is about 1.6%,a 66%reduction compared with the improved Eaton method(4.7%),indicating high accuracy;and(iii)this method has achieved remarkable results in the practical application to multiple drilling platforms in the study area;by accurately controlling the drilling fluid density according to the prediction results of the new method,the proportion of wells experiencing lost circulation reduced by 67.8%,and the leakage volume per well decreased by 48%.It is concluded that this method provides a basis for the safe drilling design of shale gas wells in the Longmaxi Formation of the Nanchuan block.In engineering practice,it can provide reliable pore pressure data to effectively guide operations such as drilling parameter optimization and the rational adjustment of drilling fluid density,mitigate lost-circulation problems,reduce the incidence of downhole complex situations and improve drilling efficiency.Meanwhile,it can serve as a reference for pore pressure prediction in similar strata,and facilitate the efficient development and utilization of shale gas resources.关键词
四川盆地东南部/南川区块/志留系/页岩气/地层压力预测模型/孔隙压力形成机制/孔隙弹性理论/钻井参数优化Key words
Southeastern Sichuan Basin/Nanchuan block/Silurian/Shale gas/Formation pressure prediction model/Pore pressure formation mechanism/Poroelasticity/Drilling parameter optimization分类
能源科技引用本文复制引用
解赤栋,龙志平,姜政华,陈雅辉,陈士奎,孙钢..南川区块志留系孔隙压力预测新方法[J].天然气勘探与开发,2025,48(4):60-69,10.基金项目
中国石油化工股份有限公司科技攻关项目"渝东南地区浅层页岩气勘探开发关键技术"(编号:P24115). （编号:P24115）
