基于测井正演量板与高斯概率场的薄(互)层砂岩厚度预测  

Prediction of thin(interbed)sand thickness based on well logging forward modeling template and Gaussian probability field

作　　者：杜昕 范廷恩 范洪军 董建华 周建楠 DU Xin;FAN Ting’en;FAN Hongjun;DONG Jianhua;ZHOU Jiannan(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》2022年第5期1174-1181,I0008-I0009,共10页Oil Geophysical Prospecting

基　　金：中国海洋石油有限公司“十四·五”重大科技项目“海上低渗及潜山油气田有效开发技术”(KJGG2022-0700)资助。

摘　　要：经典楔形模型实验假设泥岩背景下发育单砂体,但这与砂、泥岩薄(互)层发育更广泛的实情不一致,现有利用函数式拟合地震属性与砂岩厚度关系进而预测薄(互)层砂岩厚度的方法存在精度上限。为此,提出基于测井正演量板与高斯概率场的薄(互)层砂岩厚度预测方法:首先,基于W油田研究区内不同钻井的储层段测井曲线建立若干楔形模型,通过褶积正演得到适用于研究区的振幅属性—薄(互)层砂岩厚度关系量板,建立振幅属性与砂岩厚度的半定量关系;其次,以薄(互)层累积砂岩厚度与井点地震振幅属性值为数据基础,建立累积砂岩厚度—振幅属性高斯概率场,结合振幅属性—薄(互)层砂岩厚度关系量板,求得地震振幅属性对应的最可能薄(互)层砂岩厚度,最终得到最大概率薄(互)层砂岩厚度与砂岩厚度置信度平面属性。多河道三维模型与油田实际数据应用证明了该方法的有效性与可行性。The classical wedge model experiment assumes that single sand bodies are developed under the background of mudstone,which contradicts the fact that the thin(interbed)layers are more extensively developed in real situations.Additionally,the methods of employing functions to fit the relationship between seismic attributes and sand thickness for thin(interned)sand thickness have an accuracy limit.To this end,a new method for thin(interbed)sand thickness prediction is proposed based on well logging forward modeling template and Gaussian probability field.Firstly,several wedge models are built through reservoir logging curves of well logs in the W oilfield,and the relationship template of amplitude attribute vs thin(interbed)sand thickness suitable for the oilfield is obtained via convolution forward modeling.Semiquantitative relationship between amplitude attributes and sand thickness is established.Secondly,based on data of thin(interbed)accumulated sand thickness and seismic amplitude attribute value of well points,Gaussian probability field of accumulated sand thickness vs amplitude attribute is constructed.Combined with the amplitude attribute vs thin(interbed)sand thickness relationship template,the most probable thin(interbed)sand thickness corresponding to seismic amplitude attributes is solved.Finally,attribute of thin(interbed)sand thickness and sand thickness confidence with maximum probability are obtained.The effectiveness and feasibility are verified through a 3Dmodel containing several channels and actual oilfield data.

关 键 词：薄互层 累积砂岩厚度 正演量板 高斯概率场 砂岩厚度置信度 

分 类 号：P631[天文地球—地质矿产勘探]