砂质浪控滨岸相储层构型研究

Production practice shows that the wave-dominated sandy coastal reservoirs also have significant heterogeneity, as same as continental reservoirs. Internal architecture of sand body became the dominant geological factors on remaining oil distribution in the high water cut stage. But the typical subfacies sedimentary model and the understanding of architectures for wave-dominated sandy coastal reservoirs cannot meet the practical need of reservoir development. Taking Tarim basin as example, several important areas will be studied on the basis of field outcrop and core data, using the technique of outcrop observation, ground penetrating radar analysis and core analysis. We aims to reveal the hierarchy of sedimentary surface, to form the quantitative geometric characteristics of sedimentary units, and to establish the quantitative models of reservoir architecture. Mathematical models of seepage barrier distribution also will be founded, according to the relationship between reservoir architecture and seepage barrier. The purpose of this paper is to enrich reservoir sedimentology theory of wave-dominated sandy coast, and to provide theoretical basis for adjustment and potential digging of reservoirs at medium-high water cut stage.

生产实践表明，与陆相油藏类似，砂质浪控滨岸相油藏同样具有强非均质性。砂体内部结构是控制注水开发中后期剩余油分布的主要地质因素，但典型的砂质浪控滨岸亚相沉积模式及其内部储层结构认识已无法满足油藏生产实际需要。本项目拟以塔里木盆地砂质浪控滨岸相储层野外露头和油藏钻井取心为研究对象，采用野外露头观测、探地雷达分析、岩心实验等技术手段，揭示砂质浪控滨岸储层内部沉积界面级次及不同沉积单元几何学特征，确定其微相沉积类型，建立储层构型定量模式；确定渗流屏障成因类型及机理，探讨储层构型与渗流屏障之间的成因关系，建立储层内部渗流屏障分布模式及空间分布数学模型。旨在丰富砂质浪控滨岸相储集层沉积学基础理论，同时为塔里木盆地高含水期油藏剩余油预测与挖潜提供地质依据，提高油藏开发效率。

与陆相储层类似，浪控滨岸储层同样具有较强非均质性。进入油藏高含水期，储层构型及其内部渗流屏障差异化分布成为决定油藏开发效果的关键因素。本项目以现代沉积、野外露头、钻井取心、油藏覆盖区测井资料和生产动态资料等为依据，基于详测、探地雷达、激光扫描等技术手段，系统开展了塔里木盆地浪控滨岸储层沉积模式、储层构型分析及渗流屏障表征等研究。. 基于滨岸带水动力条件及沉积环境，提出了浪控滨岸相的3亚相、9微相的划分方案。在此基础上，提出了储层构型的七级划分方案，明确了13种二级构型单元成因及特征，建立了板状、楔状、槽状和千层饼状等4类构型样式概念模型，并初步确定不同概念模型的定量规模。. 基于野外露头及钻井取心资料，揭示了钙质、泥质、钙泥质等3类渗流屏障成因类型及成因机理，确定了不同类型渗流屏障的分布规律及特征，阐明了渗流屏障与储层构型之间的配置关系。通过岩心刻度测井，提出了基于“倾角+常规”测井资料的直井渗流屏障“级次控制”判别技术；揭示了水平井中渗流屏障测井响应特征，明确了不同类型渗流屏障判别标准。. 确定基于动态资料和静态资料等多信息耦合的井间渗透屏障预测技术。首先，在层序结构约束下，确定直井段和水平井段渗流屏障的匹配关系；其次，以正演模拟建立的典型储层构型概念模型的动态响应模型为依据，开展井间渗流屏障连通性及规模分析；再次，综合动态与静态资料进行井间渗流屏障拟合与建模。.开展储层构型及渗流屏障的精细表征和建模，有助于有效分析油藏覆盖区流体运移关系，能够为高含水期油藏的井位部署及调整方案优化提供技术支持。该项目部分成果已应用于塔里木油田开发生产实践，并取得了较好效果。