海相油气地质2023，Vol.28Issue(4)：425-432,8.DOI:10.3969/j.issn.1672-9854.2023.04.009
页岩气藏高精度地震地层压力预测方法及应用
High precision seismic formation pressure prediction method and application for shale gas reservoirs
摘要
Abstract
The exploration and development of shale gas reservoir have proven that formation pressure is not only the sign of gas accumulation,but also the main driving force of gas migration.It is significant for drilling design,shale dessert prediction,and horizontal well deployment with accurate prediction of formation pressure.The seismic formation pressure prediction method can effectively obtain the vertical and horizontal pressure distribution characteristics within the research area,by which it has become one of the main method for pre-drilling formation pressure prediction.The common seismic methods for predicting formation pressure can be divided into two kinds:methods based on normal compaction trend lines and methods based on the principle of effective stress.The first type requires the establishment of accurate normal compaction trend lines which depend on the experience of different researcher.The second type only considers the longitudinal wave velocity and ignores the influence of pore fluid on velocity,by which the prediction accuracy is difficult to meet the needs of shale gas reservoir exploration and development.Therefore,on the basis of absorbing the advantages of existing methods,this study constructs a new formation pressure prediction model based on the principle of effective stress.By introducing shear wave velocity to reduce the influence of pore fluid,a new formula for calculating effective stress in rocks has been derived,and a new formation pressure prediction model composed of longitudinal wave velocity,shear wave velocity,and density has been established.This method effectively improves the accuracy of formation pressure prediction and achieves quantitative prediction of shale formation pressure.The new method has been effectively applied in the LU208 well block in the southern part of Sichuan Basin.After practical drilling verification,the predicted results are highly consistent with the actual drilling,with a prediction error of less than 5%.This method is applicable to overpressure formations caused by compaction.关键词
页岩气/地层压力/有效应力/横波速度/叠前反演/龙马溪组/四川盆地Key words
shale gas/formation pressure/effective stress/shear wave velocity/pre-stack inversion/Longmaxi Forma-tion/Sihcuan Basin分类
天文与地球科学引用本文复制引用
张入化,王秀姣,石学文,陈胜,张洞君,杨亚迪,王鼐..页岩气藏高精度地震地层压力预测方法及应用[J].海相油气地质,2023,28(4):425-432,8.基金项目
本文受中国石油关键核心技术攻关项目"氦气资源评价与低成本提氦及运储关键技术研究"(编号:2021ZG1301)资助 （编号:2021ZG1301）
