中国典型咸化湖盆页岩油富集与流动特征及在“甜点”评价中的意义  

Enrichment and flow characteristics of shale oil in typical salinized lake basins in China and its significance for"sweet spot"evaluation

作　　者：赵文智[1,2] 卞从胜[1,2] 蒲秀刚 刘诗局 关铭 刘伟[1,2] 李永新[1,2] 董劲[1,2] ZHAO Wenzhi;BIAN Congsheng;PU Xiugang;LIU Shiju;GUAN Ming;LIU Wei;LI Yongxin;DONG Jin(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;ZWZ Academician Research Studio,PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;Exploration and Development Research Institute of Dagang Oilfield Company,PetroChina,Tianjin 300280,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油勘探开发研究院赵文智院士工作室,北京100083 [3]中国石油大港油田研究院,天津300280

出　　处：《中国石油大学学报（自然科学版）》2023年第5期25-37,共13页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金委员会联合基金项目(U22B6004);中国石油勘探开发研究院院级项目(2022yjcq03)。

摘　　要：咸化湖盆主要发育混积型页岩,长英质、碳酸盐矿物含量高,黏土矿物含量低,有机质形成液态烃时间偏早,但有机质丰度变化较大,且页岩油密度、黏度较高,流动性总体偏差。分析中国典型咸化湖盆页岩岩石组构、页岩油物性与流动性特征,总结提出“甜点”评价关键要素。有机质丰度较高(总有机碳TOC>1.5%或者2.0%)且单层集中段厚度较大(10~15 m或更大)的咸化湖盆页岩,在中低熟阶段(镜质体反射率R_(o)<0.8%)就可形成较多滞留烃,且纵向上具良好的源储组合,有利于页岩油近源微运移,形成富集段;混积型页岩黏土含量较低,对液态烃吸附总量较小,且页岩具有较好脆性,可保证地下可动烃数量较多,人工改造也可形成较好导流效果;页岩油主要赋存于黏土层微纳米孔隙和碳酸质与长英质层超压成因的微裂缝和构造缝中,非均质性极强,但多组分烃和非烃通过混相可改善重质烃和非烃组分的流动性,支撑中低熟液态烃有较高的流动量。此外,良好封闭性是形成异常高压的重要条件;足够高的现今地层温度(最好大于120℃)可提高中低熟页岩油地下流动性,合理的生产制度可保障多组分烃和非烃最佳混相从而形成最大流动量。具备上述条件的咸化湖盆中低熟页岩油称为“甜点”靶体,可用水平井和体积改造等非原位转化技术进行开发,并与需原位转化的淡水湖盆中低熟页岩油并列,构成中国中低熟页岩油两种主要类型,都具有良好的开发潜力,是陆相页岩油革命得于发生的重要资源基础。The salinized lake basin primarily develops hybrid sedimentary shale,characterized by a high content of felsic and carbonate minerals and a low clay mineral content.The organic matter within the hybrid sedimentary shale exhibits significant variations in abundance and tends to generate liquid hydrocarbons at an earlier stage.However,the shale oil produced from hybrid sedimentary shale has notable characteristics,including high density and viscosity,and poor fluidity.This paper analyzes the shale rock fabric,physical properties,and liquidity characteristics of shale oil in typical salinized lake basins in China,and outlines the key factors for"sweet spot"evaluation.It is observed that shale in salinized lake basin with high organic matter content(TOC>1.5% or 2.0%)and substantial concentration section thickness(typically 10 m to 15 m or thicker)can generate more residual hydrocarbons at middle to low maturity stage(R_(o)<0.8%).These shales have a favorable source-reservoir combination vertically,facilitating near-source micro-migration of shale oil and the formation of enriched sections.The low clay content in hybrid sedimentary shale results in a lower total adsorption capacity for liquid hydrocarbons.Additionally,these shales possess good brittleness,ensuring a significant volume of movable hydrocarbons,and can form good diversion effects by artificial transformation.Shale oil mainly occurs in micro-nano pores of clay layer,micro fractures and structural fractures caused by overpressure in carbonate and felsic layers,with strong heterogeneity.However,the inclusion of multi-component hydrocarbons and non-hydrocarbons aids in improving the mobility of heavy hydrocarbon and non-hydrocarbon components,supporting a high flow of liquid hydrocarbons even at medium to low maturity levels.Moreover,effective sealing conditions are crucial for abnormal high-pressure formation.A sufficiently high formation temperature(preferably>120℃)enhances the underground fluidity of medium to low mature shale oil.A well-designed produc

关 键 词：中低熟页岩油 非原位转化型 多组分烃与非烃混相 烃组分流动 控制因素 吸附性 “甜点”评价 咸化湖盆 

分 类 号：TE122[石油与天然气工程—油气勘探]