少井背景下基于稀疏层反射系数反演的薄层预测  

Prediction of thin reservoirs with less well data based on sparse-layer reflectivity inversion

作　　者：杜昕 范廷恩 范洪军 张显文 张晶玉 蔡文涛 DU Xin;FAN Ting'en;FAN Hongjun;ZHANG Xianwen;ZHANG Jingyu;CAI Wentao(CNOOC Research Institute Ltd.,Beijing 100020,China;State Key Laboratory of Offshore Oil Exploitation,Beijing 100020,China)

机构地区：[1]中海油研究总院有限责任公司,北京100020 [2]海洋石油高效开发国家重点实验室,北京100020

出　　处：《石油地球物理勘探》2021年第2期356-363,I0012,共9页Oil Geophysical Prospecting

摘　　要：稀疏脉冲反褶积的本质是恢复厚层顶、底反射界面位置,为适合厚层预测的拓频方法,并不适合以研究地震调谐效应为主要内容的薄互层预测。为此,在研究区只有一口定向开发井的背景下,提出一种少井背景下的薄储层预测技术,主要步骤为:(1)基于稀疏层反射系数反演对叠前偏移数据拓频,突破地震有效频带限制。(2)将拓频成果分频为地震低频体和高频体,利用低频体追踪主要等时面,根据地震沉积学地层切片手段搭建等时地层格架;利用90°相移技术将地震高频体转换为储层岩性估计,实现各等时单元敏感地震属性提取。(3)以地震属性值域分布直方图为基础,基于积分运算将地震属性转化为"砂体最厚发育概率"估计,进一步通过离散二值化处理得到各等时单元薄储层有利区平面展布范围。(4)将各等时单元薄储层有利区范围叠合,形成薄储层发育有利区叠合频数属性,可反映各期次薄储层发育有利区的空间叠合情况,指导薄层开发方案中定向井井位设计与优化。Sparse spike inversion aims at restoring the top and bottom of a thicker reservoir.It is less effective for interpreting thin reservoirs by focusing on seismic tuning effect.To predict the reservoir in the study area with only a well,we propose a method for predicting the thin reservoirs.The procedures include:(1)Enhance the effective frequency of PSTM data based on sparse-layer reflectivity inversion;(2)Split the wide frequency band data into low-frequency and high-frequency components through frequency division processing.Track the primary sequence stratigraphic framework on the low-frequency data and make stratal slices.Use the 90°phase shift method to convert the high-frequency data to lithology estimation,and extract the seismic attributes on the stratigraphic framework.(3) On the histogram of the attributes,use integral operation to convert the seismic attributes to a ’best reservoir probability estimation.(4)Sum up the ’best reservoir probability estimation’ in each stratigraphic unit and establish a ’cumulative frequency of favorable thin reservoir area estimation’.This attribute characterizes the spatial overlap of thin reservoirs,and can be used to guide design and location of wells for exploring the thin reservoirs.

关 键 词：薄层预测 少井背景 稀疏层反射系数反演 地震沉积学 分频处理 薄储层有利区叠合频数 

分 类 号：P631[天文地球—地质矿产勘探]