西湖凹陷B构造水下分流河道预测技术及应用

姜 勇，张 雷，邹 玮，侯志强

（中海石油（中国）有限公司上海分公司，上海 200030）

摘 要：西湖凹陷B构造的砂岩储层具有低孔渗特征，且属浅水沉积环境，水下分流河道发育，砂体横向变化快。为准确刻画砂体的横向变化，且在低孔渗储层中找到物性相对好且含油气的有利储层，研究了叠前反演技术在水下分流河道储层预测中的应用。通过岩石物理分析，找到了能够识别砂体和有利储层的参数和参数组合；通过低孔渗砂岩储层地震反射特征的研究，证实了利用叠前反演预测物性好且含气有利储层的可行性；研究了叠前反演在工区的技术流程和关键环节，利用反演结果刻画了B构造S1层水下分流河道分布范围，预测了有利储层，指导评价井位的部署。经钻探验证，预测结果得到了证实。

关键词：西湖凹陷；水下分流河道；低孔渗；叠前反演；储层预测

中图分类号：P631.4+6

文献标识码：A

DOI:10.3969/j.issn.1008-2336.2015.02.035

文章编号：1008-2336（2015）02-0035-05

收稿日期：2014-10-08；

作者简介：第一姜勇，男，1980年生，地球物理工程师，工学硕士，主要从事地震解释、储层反演等方面的研究工作。E-mail：jiangyong@cnooc.com.cn。

改回日期：2014-12-03

Technology for Prediction of Underwater Distributary Channel Reservoir and Application in B Structure, Xihu Sag

JIANG Yong, ZHANG Lei, ZOU Wei, HOU Zhiqiang

（Shanghai Branch of CNOOC Ltd., Shanghai 200030, China）

Abstract:The sandstone reservoirs in B Structure are characterized by low porosity and low permeability, deposited under shallow water depositional system, with underwater distributary channels well developed, and the sand bodies change quickly in lateral direction. For delineating the lateral change of sand bodies correctly and finding the favorable reservoirs with good physical properties and high hydrocarbon saturation from low porosity and low permeability reservoirs, pre-stack inversion technology for prediction of underwater distributary channel reservoir has been used. Based on petrophysic analysis, the elastic parameters and their combination that can be used to identify sand bodies and favorable reservoir are established. It has been confirmed through analysis of seismic characteristics of low porosity and low permeability sandstone reservoirs that it is feasible to identify favorable reservoir using prestack inversion. Then the process and key techniques for pre-stack inversion are optimized for the study area. The pre-stack inversion results have been used to delineate the geometry and distribution range of underwater distributary channels in S1 layer in Structure B, and also used to predict favorable reservoirs and guide the drilling location design of an appraisal well in B Structure. It has been confirmed by the actual drilling results that this reservoir predication technique is effective.

Keywords:Xihu Sag; underwater distributary channel; low porosity and permeability; pre-stack inversion; reservoir prediction

西湖凹陷位于东海陆架盆地，是我国近海重要的富生烃凹陷，目前已在凹陷内发现多个油气田和含油气构造。根据构造、沉积等特征，西湖凹陷自西向东可以分为西部斜坡带、西部次凹带、中央反转构造带、东部次凹带和东部断阶带[1]。研究区B构造位于西部次凹，其砂岩储层具有两个主要特征：一是目的层埋藏深，受压实作用的影响，致密砂岩储层普遍发育[2]；……