页岩油气最终采收量地质主控因素——以美国海湾盆地鹰滩页岩为例  

Key geological factors controlling the estimated ultimate recovery of shale oil and gas:A case study of the Eagle Ford shale,Gulf Coast Basin,USA

作　　者：侯连华[1] 于志超[1] 罗霞[1] 林森虎[1] 赵忠英[1] 杨智[1] 吴松涛[1] 崔景伟[1] 张丽君[1] HOU Lianhua;YU Zhichao;LUO Xia;LIN Senhu;ZHAO Zhongying;YANG Zhi;WU Songtao;CUI Jingwei;ZHANG Lijun(PetroChina Research Institute of Exploration&Development,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2021年第3期654-665,共12页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司科技部项目“非常规油气资源勘探开发技术研究”(2012A-4802-02);国家重点基础研究发展计划“中国陆相致密油(页岩油)形成机理与富集规律”(2014CB239000)。

摘　　要：基于白垩系鹰滩组下段1317口生产井和72口系统取心井991组分析化验数据,分别按油和天然气,采用两种页岩油气最终采收量(EUR)经典模型预测单井最终采收量,以消除工程因素的预测均值作为最终结果,全面厘清控制页岩油气EUR的关键地质因素。研究表明:储集能力、资源量、流动能力和可压性是控制页岩油气EUR的4个关键地质因素。储集能力直接受控于总孔隙度和含烃孔隙度,间接受控于TOC和R_(o);资源量受控于含烃孔隙度、有效页岩厚度等参数;流动能力受控于有效渗透率、原油密度、气油比、凝析油气比、地层压力梯度和R_(o)等参数;可压性直接受控于脆性指数,间接受控于黏土体积含量。页岩油气EUR主要受控于6个地质参数,EUR与有效页岩厚度、总有机碳含量、裂缝孔隙度呈正相关关系,与黏土体积含量呈负相关关系,与R_(o)、地层压力梯度呈先增大后减小关系。现有水平井压裂技术的单井有效压裂厚度上限约65 m;EUR下限值为3×10^(4)m^(3)油当量条件下,当TOC<2.3%或R_(o)<0.85%或黏土体积含量大于25%,且裂缝或微裂缝不发育时,很难形成页岩油气的有利发育区。Based on 991 groups of analysis data of shale samples from the Lower Member of the Cretaceous Eagle Ford Formation of 1317 production wells and 72 systematic coring wells in the U.S.Gulf Basin,the estimated ultimate recovery(EUR)of shale oil and gas of the wells are predicted by using two classical EUR estimation models,and the average values predicted excluding the effect of engineering factors are taken as the final EUR.Key geological factors controlling EUR of shale oil and gas are fully investigated.The reservoir capacity,resources,flow capacity and fracability are the four key geological parameters controlling EUR.The storage capacity of shale oil and gas is directly controlled by total porosity and hydrocarbon-bearing porosity,and indirectly controlled by total organic carbon(TOC)and vitrinite reflectance(R_(o)).The resources of shale oil and gas are controlled by hydrocarbon-bearing porosity and effective shale thickness etc.The flow capacity of shale oil and gas is controlled by effective permeability,crude oil density,gas-oil ratio,condensate oil-gas ratio,formation pressure gradient,and R_(o).The fracability of shale is directly controlled by brittleness index,and indirectly controlled by clay content in volume.EUR of shale oil and gas is controlled by six geological parameters:it is positively correlated with effective shale thickness,TOC and fracture porosity,negatively correlated with clay content in volume,and increases firstly and then decreases with the rise of R_(o) and formation pressure gradient.Under the present upper limit of horizontal well fracturing effective thickness of 65 m and the lower limit of EUR of 3×10^(4)m^(3),when TOC<2.3%,or R_(o)<0.85%,or clay content in volume>25%,and fractures and micro-fractures aren’t developed,favorable areas of shale oil and gas hardly occur.

关 键 词：页岩油气 甜点 最终采收量 总有机碳含量 镜质体反射率 有效页岩厚度 黏土体积含量 地层压力系数 裂缝孔隙度 鹰滩组下段 

分 类 号：TE122.3[石油与天然气工程—油气勘探]