Title

Prediction of channel sand body distribution in deep water area of Baiyun sag

单位

(1.中海石油(中国)有限公司深圳分公司,广东深圳518000;2.中国石油大学(北京)油气资源与探测国家重点实验室,北京102249;3.中国石油大学(北京)地球物理学院,北京102249)

Organization

(1.Shenzhen Branch,CNOOC China Limited,Shenzhen 518000,China;2.State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum-Beijing,Beijing 102249,China;3.College of Geophysics,China University of Petroleum-Beijing,Beijing 102249,China)

摘要

珠江口盆地白云凹陷深水区有利储层以重力流水道与深水扇沉积为主,针对砂体厚度横向变化大,利用常规技术手段难以准确落实砂体尖灭位置的问题,提出了多窗重排平滑伪Wigner-Ville分布时频分析方法,利用多个正交Hermite窗削弱时频重排对平稳谱的截断效果,在保证时频谱高聚焦性的同时,使时频能量能够准确归位到真实位置。与其它时频分析方法相比,该方法具有较好的时频分辨率和能量聚集性。在高分辨率时频分析基础上,提出基于“时频脊线”的频率信息提取方法。通过时频脊线的拾取以及标准线的确定,从时频谱图中提取出高频能量和高频加权能量,能够识别小型河道及薄扇体,准确落实砂体的尖灭位置,提升薄砂体的识别能力。并综合其它储层预测手段,利用地震多属性聚类结果预测大型河道及厚扇体,揭示储层砂体的主体位置,展示砂体的宏观分布特征,通过RGB混频融合直观反映不同厚度砂体的展布规律。多种预测结果互为检验,精细刻画了研究区河道砂和深水扇的空间展布形态。

Abstract

Baiyun Sag is one of the main hydrocarbon-rich sags in the Pearl River Mouth Basin.Favorable oil and gas reservoirs are typically deep-water gravity flow channel sandstone deposits and shelf edge delta sandstone reservoirs.However,the lateral variation in sand body reservoirs is large,which makes them difficult to effectively identify through traditional exploration technology,and it is difficult to determine the reliable pinch-out position of channel sand body by using seismic amplitude information.To solve these problems,this study introduces the multi-window idea into the rearrangement smoothing pseudo Wigner-Ville distribution and proposes a time-frequency analysis method for multi-window rearrangement and smoothing pseudo Wigner-Ville distribution.This method uses multiple orthogonal Hermite windows to weaken the influence of the truncation effect on results,which not only ensures a high focus for the time-frequency spectrum but also disperses the interference of noise,allowing the time-frequency energy to be accurately located to the real position.Compared with other time-frequency analysis methods,the proposed method improved time-frequency resolution and energy aggregation.On this basis,a frequency information extraction method based on “time-frequency ridge” is proposed.By fully extracting the high-frequency information in the time-frequency spectrum,this method significantly improves the recognition of thin sand bodies,small river channels,and thin fan bodies,and can accurately determine the pinch-out position of sand bodies.Combining other reservoir prediction methods,the seismic multi-attribute clustering results are used to predict large river channels and thick fans,reveal the main position of reservoir sand bodies,and show the macro distribution characteristics of sand bodies.Based on RGB mixing fusion,the distribution trends of sand bodies with different thicknesses are intuitively reflected.A variety of prediction results are mutually evaluated,and the spatial distribution patterns of channel sand and deep-water fans in the study area are finely characterized.

关键词：

时频分析; 高分辨率; RGB融合; 聚类分析; 储层预测; 河道砂体; 深水油气勘探;

Keywords:

time frequency analysis;; high resolution;; RGB fusion;; cluster analysis;; reservoir prediction;; channel sand;; deep-water exploration;

基金项目

基金项目：中海油“十三五”科技重点项目(CNOOC-KJ135ZDXM37SZ01SHENHAI)资助。

DOI

10.3969/j.issn.1000-1441.2022.05.013

白云凹陷深水区河道砂体分布预测