天然气工业2025，Vol.45Issue(5)：69-78,10.DOI:10.3787/j.issn.1000-0976.2025.05.006
四川盆地威远—资阳地区寒武系筇竹寺组页岩气全程各向异性地震成像新方法
A new method for full-process anisotropic seismic imaging technology of Qiongzhusi shale gas in the Weiyuan-Ziyang Area,Sichuan Basin
摘要
Abstract
The Cambrian strata in Weiyuan-Ziyang area of the Sichuan Basin exhibit a structural pattern characterized by a monocline dipping northeastward from the Weiyuan anticline.This region is a favorable development zone for shale gas in the Cambrian Qiongzhusi Formation.The Qiongzhusi Formation in the Weiyuan-Ziyang area develops multiple sets of high-angle strike-slip faults,with small fault displacements both longitudinally and transversely.Additionally,due to the strong heterogeneity of small layers within the Qiongzhusi Formation and significant anisotropy differences,conventional grid-based tomography and isotropic-to-anisotropic pre-stack depth migration(PSDM)techniques fail to fully delineate structural configurations,leading to substantial well-seismic discrepancies.To ensure high target-zone drilling rates for horizontal wells in the Qiongzhusi Formation,an anisotropic imaging workflow for the shale in the Qiongzhusi Formation is proposed.This workflow integrates first-arrival velocity inversion with multi-information to establish an initial velocity model that better aligns with actual stratigraphic patterns.On the basis of incorporating anisotropic parameters into tomographic inversion,it combines structure-based layer-by-layer tomography,small-scale gridded tomography,and full-azimuth angle domain grid tomography to update the velocity model and thus improve the model accuracy.The use of angle-domain imaging technology further enhances imaging accuracy.The research results indicate:(1)When the initial model is established,anisotropic,seismic,logging,and geological information is incorporated,and the velocity model is more consistent with stratigraphic characteristics;(2)The velocity model is updated with significantly higher precision through the combination of layer-by-layer tomography,small-scale gridded tomography,and full-azimuth angle domain grid tomography;(3)Angle-domain imaging technology yields superior results,significantly enhancing imaging quality for Qiongzhusi shale.In conclusion,the full-process anisotropic seismic data imaging technology can significantly improve the accuracy of the velocity model and enhance the imaging resolution of small faults in the Qiongzhusi Formation shale,ensuring efficient development of shale gas in the Cambrian Qiongzhusi Formation of the Weiyuan-Ziyang area.关键词
四川盆地/威远—资阳地区/筇竹寺组/页岩气/全程各向异性/高精度速度建模/叠前深度偏移Key words
Sichuan Basin/Weiyuan-Ziyang Area/Qiongzhusi Formation/Shale gas/Full anisotropy/High-precision velocity modeling/Pre-stack depth migration分类
能源科技引用本文复制引用
郑马嘉,周祺,林杨,陆林超,彭浩,张洞君,邓绍强,梅杰,向大蔚..四川盆地威远—资阳地区寒武系筇竹寺组页岩气全程各向异性地震成像新方法[J].天然气工业,2025,45(5):69-78,10.基金项目
中国石油天然气股份有限公司西南油气田公司科技项目"川南地区筇竹寺组深层页岩气'双高'采集方法试验及处理解释技术研究"(编号:2024D101-03-04). （编号:2024D101-03-04）
