川南下寒武统筇竹寺组地震勘探难点与关键采集技术

Difficulties and Key Acquisition Techniques in Seismic Exploration of the Qiongzhusi Formation in the Southern Sichuan Basin

段文燊 吴朝容 涂远艮

DUANWenshen WUChaorong TUYuangen

中国石化西南油气分公司, 四川 成都 610041 成都理工大学地球物理学院, 四川 成都 610059

Southwest Oil and Gas Company, SINOPEC, Chengdu, Sichuan 610041, China Geophysics College, Chengdu University of Technology, Chengdu, Sichuan 610059, China

川南下寒武统筇竹寺组广泛分布，是重要的页岩气勘探开发层系。该页岩气区具有地面、地下双复杂的特征，面临着地形起伏较大、地表出露灰岩、地下构造高陡、煤矿采空区多、施工效率低等地震勘探难题。经过10多年研究与实践，形成了5项关键采集技术： 1）细分面元采集的观测系统，提升主要目的层覆盖次数和纵横比，有效控制采集成本； 2）形成了优选激发地形、优化激发岩性、均衡激发能量、增强激发耦合等激发技术； 3）形成了优化检波器选型、优选检波器位置、做实检波器埋置、控制接收时噪声等采集信号接收控制技术； 4）通过煤矿开采区模型照明分析和现场试验，形成了煤矿采空区提升接收效果的配套技术，改善了采空区的资料采集质量； 5）通过节点仪的推广使用，大幅度提升了施工效率。研究的配套关键采集技术较好解决了复杂地区页岩气地震勘探问题，在5个工区采集三维地震资料超过2 000 km，为页岩气勘探开发提供了重要技术支持。

The Qiongzhusi Formation of Lower Cambrian is widely distributed in the southern Sichuan Basin and is an important shale gas layer for exploration and development. This area has complex geological characteristics both on the surface and underground, facing seismic exploration challenges, such as large terrain undulations, exposed limestone on the surface, high and steep underground structures, multiple coal mine goafs, and low operation efficiency. After more than 10 years of research and practice, key technologies have been developed to solve the difficulties in seismic exploration of the Qiongzhusi Formation in the southern Sichuan Basin: 1) subdivision of the surface element acquisition and observation system, improving the coverage frequency and the aspect ratio of the main target layer, and effectively controlling the acquisition cost; 2) explosion techniques such as optimizing terrain, optimizing lithology, balancing excitation energy, and enhancing explosion coupling; 3) techniques for acquiring and controlling signals that optimize detector selection, detector positions, detector placement implementation, and noise control when receiving; 4) a supporting technology for improving the receiving effects of coal mine goaf through the analysis of lighting models and on-site experiments in coal mining area, which has improved the quality of data acquisition in goaf areas; 5) the promotion and use of node meters that have significantly improved the efficiency of data acquisition. The key acquisition techniques developed for the research have effectively solved the problem of shale gas seismic exploration in complex areas, collecting over 2 000 km of 3D seismic data in five work areas, providing important technical support for shale gas exploration and development.

10.11885/j.issn.1674-5086.2024.12.07.01