摘要
总有机碳含量(w(TOC))是评价页岩气储层生烃能力的重要指标,也是页岩气甜点预测的关键参数之一。页岩气储层w(TOC)地震定量预测是通过地震岩石物理分析,优选储层w(TOC)敏感参数,得到基于地震弹性参数的w(TOC)计算模型;通过全道集叠前反演获得高精度弹性参数反演数据体,根据计算模型将反演数据体转换为w(TOC)数据体,从而定量预测页岩气储层w(TOC)的空间展布。应用该方法对四川盆地LZ区块上奥陶统五峰组—下志留统龙马溪组页岩气储层w(TOC)空间展布进行了研究。结果表明:基于全道集的叠前反演技术充分利用叠前道集中的AVO信息刻画出储层内部特征变化,有效提高弹性参数的反演精度;确定密度为LZ区块w(TOC)的敏感参数,结合全道集叠前密度反演获得w(TOC)数据体,预测出五峰组—龙一1亚段储层w(TOC)空间及平面分布;LZ区块6口井w(TOC)地震定量预测结果与测井解释结果对比,相对误差均小于5%。页岩气储层w(TOC)地震定量预测方法能有效预测w(TOC)的空间分布,为页岩气开发设计提供可靠依据。
Total organic carbon content w(TOC)is an important indicator to evaluate the hydrocarbon generation capacity of shale gas reservoirs,and also one of the key parameters for the shale-gas sweet-spot prediction.Through the seismic petrophysical analysis,the w(TOC)sensitive parameters of the shale gas reservoirs were optimized to obtain the w(TOC)calculating model based on the seismic elastic parameters,thus the seismic quantitative prediction of the w(TOC)of the reservoirs was conducted.By means of the all-gather prestack inversion,the high-precision seismic elastic parameter inversion data volume was converted,and then was changed into one of the w(TOC)according to the calculating model,so as to quantitatively predict the spatial distribution of the w(TOC)in the shale gas reservoirs.The method was applied in the study on the spatial distribution of the w(TOC)of the shale gas reservoirs in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Block LZ of Sichuan Basin.The results show that with the help of all-gather prestack inverting technique,making full use of the AVO information in the prestack gather,the changes of the internal characteristics of the reservoirs were figured out,thus the inversion precision of the elastic parameters was effectively enhanced.The density was determined to be the sensitive parameter for the w(TOC)in Block LZ,and the w(TOC)data volume was obtained by integrating with the all-gather prestack density inversion,and moreover the spatial and planar distributions of the w(TOC)from Wufeng Fm(Ow)to L1,submember of Longmaxi Fm(Sl)were predicted.The comparison between the seismic quantitative result and the well logging interpretation for the w(TOC)in six wells in Block LZ shows that the relative errors are all less than 5%.The seismic quantitative prediction method of the w(TOC)in the shale gas reservoirs can effectively predict the spatial distribution of the w(TOC),which provides the reliable evidence for the shale gas development design.
作者
王梦
康昆
龙浩
李鸿明
李文佳
周津宇
赖娟
WANG Meng;KANG Kun;LONG Hao;LI Hongming;LI Wenjia;ZHOU Jinyu;LAI Juan(CNPC BGP Southwest Geophysical Research Institute,Chengdu 610213,China)
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2021年第3期130-136,共7页
Petroleum Geology & Oilfield Development in Daqing
基金
“十三五”国家科技重大专项“大型油气田及煤层气开发”(2016ZX05062001)。
