地震横波建模技术及其在深水天然气田储层预测中的应用
Seismic S-wave modeling technology and its application in deep-water gas field reservoir prediction
敖威 1张卫卫 1汪旭东 1杨学奇 1李志晔1
作者信息
- 1. 中海石油(中国)有限公司深圳分公司,广东深圳 518054
- 折叠
摘要
深水区缺少横波资料,在叠前反演的建模环节中,一般通过线性关系或者相控将纵波模型转换为横波模型,但实现过程受人为因素影响较大,反演结果无法完整、可靠地表征地层特点和储层分布.为此,结合生产需求,提出基于远道地震数据提取三维空间的泊松比信息,作为纵、横波数据之间的转换关系,进而获得泊松比约束的横波低频模型.具体步骤为:①优选对岩性敏感的地震波入射角;②反演泊松比弹性阻抗PEI;③建立横波低频模型.在白云深水区的勘探实践表明,由于初始模型更好地反映了地层岩性背景,减少了反演结果的异常值,2号砂体的平面分布与气/水边界吻合,与实钻结果一致,落实了储层分布,扩大了天然气探明储量,取得了较好的经济效益.
Abstract
Due to the lack of shear wave(S-wave)data in deep-water area,the P-wave model is generally con-verted to the S-wave model through linear relationship or phase control in the modeling process of pre-stack in-version.However,those methods may bring uncertainty due to human influence,and pre-stack inversion re-sults cannot fully and reliably represent the formation characteristics and reservoir distribution.Therefore,com-bining with the production demand,this paper proposes to extract Poisson's ratio information in three-dimen-sional space based on wide angle seismic data as the conversion relationship between P-wave and S-wave data,and then obtain the low-frequency model of S-wave constrained by Poisson's ratio.The specific steps are as follows:Firstly,the study evaluates the incident angle which is sensitive to the lithology in the formation.Secondly,the study extracts Poisson's ratio elastic impedance(PEI)with post-stack inversion based on far-angle seismic.Thirdly,the study converts the P-wave model into the S-wave model with the PEI.The explora-tion practice in the Baiyun deep-water area shows that pre-stack inversion results can clearly reflect the geologi-cal and lithologic information,and the plane distribution of No.2 sand body is consistent with the gas/water boundary and the real drilling results,which confirms the reservoir distribution,expands the proved natural gas reserves,and achieves good economic benefits.
关键词
叠前反演/纵波模型/横波模型/泊松比弹性阻抗/白云深水区Key words
pre-stack inversion/P-wave model/S-wave model/Poisson's ratio elastic impedance/Baiyun deep-water area引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据