基于地层切片的小尺度沉积相定量解释方法  

Quantitative Interpretation Method of Small-Scale Sedimentary Facies Based on Strata Slice

作　　者：张兆辉[1] 刘化清[1] 苏明军[1] 

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020

出　　处：《吉林大学学报（地球科学版）》2016年第3期893-899,共7页Journal of Jilin University：Earth Science Edition

基　　金：国家重大科技专项(2011ZX05001-003);中国石油天然气股份有限公司项目(2008-030504)~~

摘　　要：利用地震资料研究沉积相,传统上采用波形分类法和地震结构属性映射法进行的可识别的大尺度(大于λ/4,λ为波长)、定性程度的地震沉积相分析,无法满足薄层(小于λ/4)为主的岩性油气藏勘探需求。地层切片作为地震沉积学研究的关键技术,前人认为沉积体的地震成像在水平方向上比纵向上更易识别,可以清晰描述出沉积体的平面展布特征,为小尺度(通常小于λ/4,甚至更小,达到单砂层级别)沉积相平面展布研究提供可靠的资料基础。而尺度大小主要依据地层切片采样率而论,采样率越高,研究尺度越小。首先以井点沉积微相属性提取、优选、融合为基础,获取指相特征属性体;然后以此数据体制作地层切片,在"所见即所要"的图像处理准则下,对地层切片进行处理,主要包括图像分割、边界线平滑等;最后利用沉积微相-指相特征属性-地层切片图像特征之间的数学映射关系,对分割区域进行地质标定,基本实现地震资料研究沉积相从定性到定量、从大尺度到小尺度的发展。沉积相边界较以往单纯通过井控外推法得到的更加精确,可为相控储层预测奠定基础,为勘探、开发阶段井位部署提供依据。Traditional waveform classification and reflection structure attribute mapping based on seismic data are used for the recognition of large scale（ larger than λ /4） and the qualitative sedimentary facies,however,they cannot satisfy the requirements for exploration of the thin layer（ less than λ /4）. Strata slice is the key technology of seismic sedimentology,it is found that the deposit body in seismic data is easier to identify in horizontal imaging than vertical direction,it also clearly describes the distribution features and provides the reliable data for small-scale（ usually less than λ /4,even the level of single layer） sedimentary facies analysis.Scale size mainly depends on the sampling ratestrata slice,the higher the sampling rate is,the smaller the targetsize is. Firstly,based on the extraction,optimization,and fusion of sedimentary microfacies attributes at the well points,the proposed method gets the feature attributes data of sedimentary microfacies,which is used for making strata slices,then we process the strata slices according to the rule of ＂what you see is what you want! ＂that includes image segmentation and smoothing boundary lines. Finally,we label the segmentation regions using the mathematical mapping relationship among sedimentary microfacies,feature attributes,and image characteristics of strata slices. In this paper,the interpretation method of sedimentary facies based on seismic data is developed from qualitative to quantitative and from large scale to smaller scale. The boundary lines of sedimentary facies are more precise than well-control extraction,it provides the data basis for reservoir prediction and well placement inexploration and development stage.

关 键 词：指相特征属性 地层切片 地震沉积学 图像处理 

分 类 号：P631.4[天文地球—地质矿产勘探]