Walkaway 和Walkaround VSP技术在东海深层气田中的应用  

Application of offshore Walkaway and Walkaround VSP for deep gas field in East China Sea basin

作　　者：高顺莉 胡森清 鲁法伟 王小刚 张国栋 姜雨 刘春锋 GAO Shun-li;HU Sen-qing;LU Fa-wei;WANG Xiao-gang;ZHANG Guo-du;JIANG Yu;LIU Chun-feng(CNOOC China Limited-Shanghai,Shanghai 200335,China;Geophysical-China Oilfield Technology Limited,Hebei Yanjiao 065200,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]中海油服油技事业部,河北燕郊065200

出　　处：《地球物理学进展》2019年第5期2016-2021,共6页Progress in Geophysics

基　　金：国家科技重大专项课题“东海深层大型气田勘探评价技术”(2016ZX05027-02)资助

摘　　要：海上非零偏VSP技术是一项在地震船井周放炮以实现变井源距激发、井筒中布设三分量检波器进行接收的井筒物探技术.本次试验采集是Walkaway和Walkaround VSP在中国近海海域深层气田的首次非零偏VSP联合试验,为改善海上深层常规拖缆三维地震资料品质提出了新的解决方案.东海盆地存在目的层埋藏深、构造复杂以及储层非均质性强等特殊地质条件,常规拖缆地震采集处理存在多次波发育、信噪比和分辨率低等问题.经过优选试验靶区,开展采集模拟设计,优化采集方式和采集参数等确定了观测系统,在东海深层开展了四个方向的Walkaway VSP以及两个不同半径环线的Walkaround VSP现场作业,通过精细处理获得了井周精细构造及储层信息.同时,利用非零偏地震资料求取衰减因子和多次波模型等相关地震参数,通过井控三维处理得到分辨率和信噪比增强的拖缆三维地震数据.实际应用及分析表明,该项井震结合技术可有效提高地震资料品质,对海上深层气田砂体追踪和气藏描述效果良好.Offshore non-zero offset VSP technology is a borehole geophysical exploration technology which is shooting around borehole to realize variable borehole source distance and three-component geophones in the borehole for receiving. This test acquisition is the first non-zero offset VSP joint test of Walkaway and Walkaround VSP in deep gas fields in offshore China, providing a new solution for improving the quality of 3 D seismic data of conventional streamers. Oil and gas exploration in East China Sea basin reveals some special geological conditions: deep reservoir, complex structure and reservoir anisotropy which cause many problems in conventional streamer seismic acquisition and processing, such as multiple, low signal-to-noise ratio and low resolution. After selecting the test well, making acquisition simulation design, optimizing the acquisition mode and parameters, W-VSP acquisition was conducted by placing geophone in the borehole and shooting around by seismic vessel and fine structure and reservoir information around the wellbore are obtained by processing. Meanwhile, relevant seismic parameters such as attenuation factor and multiple models are obtained through W-VSP, so we obtained high quality 3 D seismic data with enhanced resolution and signal-to-noise ratio through W-VSP drive 3 D processing. The test shows that the seismic image can be effectively improved by this technology, which is good for sand tracing and gas reservoir description in offshore deep gas fields.

关 键 词：东海深层 Walkaway VSP Walkaround VSP 井控处理 储层描述 

分 类 号：P631[天文地球—地质矿产勘探] P738[天文地球—地质学]