一种薄互层条件下致密砂体展布地震综合预测的策略  

A seismic prediction strategy for tight sand body distribution in thin interbedded layers

作　　者：王团[1] WANG Tuan(Exploration and Development Research Institute of Daqing Oilfield Ltd,Daqing 163712,China)

机构地区：[1]大庆油田有限责任公司勘探开发研究院,大庆163712

出　　处：《物探化探计算技术》2024年第6期677-685,共9页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中国石油天然气股份有限公司重大科技专项(2016E-0201);中央引导地方科技发展专项(ZY20B13)。

摘　　要：松辽盆地北部上白垩统高台子油层发育典型的致密砂岩储层,属于三角洲前缘沉积环境,该套地层从上至下有三套主力砂层组,每套砂层组均为砂泥岩薄互层,单层砂岩厚度超薄,一般为2 m~3 m。寻找区域内砂体比高的砂层组并刻画砂组内部单砂体空间分布是致密油勘探开发的关键所在。而常规属性分析及地震反演储层预测效果差、精度低,为此提出了针对性的地震综合预测策略,除地震资料保真高分辨率处理和岩石物理分析外,主要包括砂层组级的多属性融合砂地比预测技术以及单砂体级的相控地质统计学反演技术。具体工作流程为:第一在地震属性归一化基础上,利用聚类分析方法将地震属性划分为三大类,每类挑选相关性最高的地震属性进行多元线性拟合,建立砂层组级的多属性融合砂地比预测模型;第二利用统计分析手段建立井点先验信息与砂地比对应关系,建立砂地比先验信息约束的单砂体级的相控地质统计学反演方法。松辽盆地北部某区块应用实例表明,综合预测策略在评价砂层组级的砂体发育情况、刻画砂层组内部薄砂体空间展布方面取得较好的效果,指导了水平井井组的部署方案优化设计。The Upper Cretaceous Gaotaizi oil layer in the northern Songliao Basin develops a typical tight sandstone reservoir in the delta front sedimentary environment.There are three main sand formations from top to bottom in this set of strata,each of which is a thin interbed of sand and mudstone,and the thickness of a single sandstone is ultra-thin,generally 2-3m.The key to tight oil exploration and development is to find a sand formation with a high net-to-gross ratio in the target area and to characterize the spatial distribution of a single sand body in the sand formation.However,conventional attribute analysis and seismic inversion have poor reservoir prediction results and low accuracy.For this reason,a targeted,comprehensive seismic prediction strategy is proposed.In addition to fidelity and high-resolution processing of seismic data and petrophysical analysis,it mainly includes multi-attribute fusion net-to-gross ratio prediction technology of sand formation and facies-controlled geostatistical inversion technology of single sand body.The specific workflow is as follows:based on seismic attribute normalization,the seismic attributes are divided into three categories using the cluster analysis method,and each category selects the seismic attributes with the highest correlation for multivariate linear fitting and establishes a multi-attribute fusion net-to-gross ratio prediction model of sand formation;secondly,the corresponding relationship between the prior information of well point and the net-to-gross ratio is established by using statistical analysis method,and the facies-controlled geostatistical inversion method of single sand body constrained by the prior information of net-to-gross ratio is established.The application example in the north of Songliao Basin shows that the comprehensive prediction strategy has achieved satisfactory results in evaluating the development of sand bodies and depicting the spatial distribution of thin sand bodies in the sand formation,which guides the optimal design of the deplo

关 键 词：三角洲前缘 薄互层 致密砂岩 砂层组 砂地比预测 单砂体预测 

分 类 号：P618.13[天文地球—矿床学]