摘要
四川盆地威远—资阳地区是寒武系筇竹寺组页岩气有利建产区,该区寒武系构造表现为由威远背斜向北东向下倾的单斜构造,且筇竹寺组发育多组系高角度走滑断层,断层纵横向断距小,加之筇竹寺组内小层非均质性强且各向异性差异大,常规网格层析和叠前深度偏移技术无法精细准确刻画构造展布特征,导致井震误差大,制约了该层系页岩气的勘探开发效果。为了提升该区筇竹寺组页岩气水平井靶体钻遇率,以地震、地质、钻井、测井等多信息融合为基础,以构造成像建模与网格层析成像为核心,提出了一套适用于筇竹寺组页岩的各向异性速度建模和偏移成像技术流程,大幅提高了筇竹寺组页岩的成像精度,并在威远—资阳地区寒武系页岩气取得了良好应用效果。研究结果表明:①基于地震、地质、钻井、测井等多信息融合建立了符合该区地质规律的各向异性初始速度模型;②在各向异性参数参与层析反演基础上,将基于构造的沿层层析反演、小尺度网格层析反演、全方位角度域网格层析反演三者相结合,有效提高了速度反演的精度,然后采用角度域成像技术提高了成像精度;③将该流程应用于筇竹寺组实际资料处理中,筇竹寺组反射特征横向保真性好,成像效果佳,纵向高角度断裂成像清楚,地震和钻井吻合程度明显提升。结论认为,全程各向异性地震资料成像技术可大幅提高速度建模精度和该区筇竹寺组页岩小断裂的成像品质,该技术为威远—资阳地区寒武系筇竹寺组页岩气高效开发提供了数据支撑和技术保障。
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.
作者
郑马嘉
周祺
林杨
陆林超
彭浩
张洞君
邓绍强
梅杰
向大蔚
ZHENG Majia;ZHOU Qi;LIN Yang;LU Linchao;PENG Hao;ZHANG Dongjun;DENG Shaoqiang;MEI Jie;Xiang Dawei(Development Department,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;PetroChina ResearchInstitute of Petroleum Exploration&Development,Beijing 100082,China;BGP In.,China National Petroleum Corporation SouthwestGeophysical Research Institute,Chengdu,Sichuan 610213,China;PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan610051,China;Shale Gas Research Institute of PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China)
出处
《天然气工业》
北大核心
2025年第5期69-78,共10页
Natural Gas Industry
基金
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)。
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
Sichuan Basin
Weiyuan-Ziyang Area
Qiongzhusi Formation
Shale gas
Full anisotropy
High-precision velocity modeling
Pre-stack depth migration
