摘要
四川盆地及其周缘页岩气资源丰富,选区评价是获取页岩气区块并实现勘探开发的前提,然而目前页岩气选区评价关键参数并不统一,关键参数标准及上下限仍存在争议并缺乏系统性研究,因此亟需建立一套适用于高热演化海相页岩气的选区评价体系。充分调研了国内外页岩气选区评价方法、行业和企业标准及公开文献,开展了各类选区评价参数统计,优选了选区评价关键参数,探究了每个关键参数的上下限,建立了页岩气选区评价关键参数取值范围标准。研究优选出7个页岩气选区评价关键参数,主要包括有机碳含量(TOC)、成熟度(R_(O))、孔隙度、压力系数、埋藏深度、脆性矿物含量和页岩有效厚度。有机碳含量作为页岩气选区评价的首要关键参数,其下限可降到1.0%;成熟度R_(O)是页岩气聚集形成的重要指标,其下限仍为1.3%,上限可提高至4.0%;孔隙度作为页岩储层评价的重要参数,其下限仍为2.0%;压力系数作为页岩气的保存参数,其下限可降至1.0;页岩埋藏深度的上下限分别为1 000 m和5 000 m;脆性矿物含量作为压裂参数,其下限仍为40%;页岩有效厚度应选取TOC>2.0%、1.3%<R_(O)<3.5%、孔隙度>2.0%和脆性矿物含量>40%的页岩层段,其下限为20 m。优选的选区评价关键参数及建立的上下限标准,对中国复杂构造背景下的高过成熟海相页岩气的选区评价和高效勘探开发具有重要指导意义。
Shale gas resources are abundant in the Sichuan Basin and its periphery areas, and the shale gas selection evaluation is a prerequisite for obtaining blocks and realizing exploration and development. However, the key parameters for shale gas selection evaluation are not uniform, and the parameter criteria and the upper-lower limits are still controversial and lack systematic researches. Therefore, there is an urgent need to establish an applicable selection evaluation system for highly thermally evolved marine shale gas. This study fully investigated the domestic and international shale gas selection evaluation methods, industry standards and references. Various parameters for shale gas selection evaluation were carried out by mathematical statistics, the key selection parameters were preferred, and the upper-lower limits of each key parameter were explored and the criteria for the key parameters for shale gas selection evaluation were delineated. In this study, seven key parameters for shale gas selection evaluation were preferentially selected, mainly including total organic carbon content(TOC), thermal maturity(R_(O)), porosity, pressure coefficient, burial depth, brittle mineral content and effective shale thickness. TOC content acts as the primary key parameter for shale gas selection evaluation, its lower limit can be reduced to 1.0%. R_(O), an important indicator for shale gas accumulation, remains the lower limit of 1.3% and the upper limit can be raised to 4.0%. Porosity, an important parameter for shale reservoir evaluation, its lower limit can still be 2.0%. Pressure coefficient acts as a preservation parameter for shale gas, with a lower limit down to 1.0. The upper-lower limits of shale burial depth are 1 000 m and 5 000 m, respectively.The brittle mineral content acts as a fracturing parameter, with the lower limit remaining at 40%. The effective shale thickness should be selected from the shale section with TOC > 2%, 1.3% < R_(O)< 3.5%, porosity >2% and brittle mineral content > 40%, and with the lower limit of 20 m. The set of selection evaluation system for highly evolved marine shale gas established in the paper is an important guideline for shale gas exploration and development.
作者
唐令
宋岩
陈晓智
姜振学
张帆
李倩文
马晓强
TANG Ling;SONG Yan;CHEN Xiaozhi;JIANG Zhenxue;ZHANG Fan;LI Qianwen;MA Xiaoqiang(Research Institute Co.,Ltd.of China National Offshore Oil Corporation,Beijing 100028,China;Unconventional Oil and Gas Science and Technology Research Institute,China University of Petroleum(Beijing),Beijing 102249,China;SINOPEC Petroleum Exploration&Production Research Institute,Beijing 102206,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2023年第1期153-168,共16页
Natural Gas Geoscience
基金
中海油油气勘探战略选区研究(编号:2021OT-XNY01)
国家科技重大专项“大型油气田及煤层气开发”(编号:2017ZX05035006)联合资助.
关键词
选区评价
关键参数
上下限
四川盆地
五峰组—龙马溪组
Selection evaluation
Key parameters
Upper-lower limits
Sichuan Basin
Wufeng-Longmax formations
作者简介
唐令(1990-),男,四川达州人,工程师,博士,主要从事非常规油气形成与分布、资源评价等研究.E-mail:tangling8@cnooc.com.cn.
