低煤阶煤储层物性演化特征及其对储层评价的影响  

Physical property evolution of low-rank coal reservoir and its influence on reservoir evaluation

作　　者：辛福东 许浩[1,2,3] 汤达祯 杨焦生[4] 陈艳鹏 王玫珠[4] Xin Fudong;Xu Hao;Tang Dazhen;Yang Jiaosheng;Chen Yanpeng;Wang Meizhu(School of Energy,China University of Geosciences,Beijing 100083,China;Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&Utilization,China University of Geosciences,Beijing 100083,China;Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]煤层气开发利用国家工程研究中心中国地质大学(北京)煤储层物性实验室,北京100083 [3]非常规天然气地质评价与开发工程北京市重点实验室,北京100083 [4]中国石油勘探开发研究院,北京100083

出　　处：《石油学报》2022年第5期637-647,共11页Acta Petrolei Sinica

基　　金：国家科技重大专项(2016ZX05041-002);国家自然科学基金项目(No.U1703126,No.42172188);中央高校基本科研业务费优秀导师基金项目(2652019259)资助。

摘　　要：“第一次煤化作用跃变”使煤储层的物性在煤化作用早期阶段发生了显著的变化。鉴于这一物性动态变化特征,为厘定煤化作用跃变前后低煤阶有利煤储层的评价参数和标准,在系统采集中国主要盆地低煤阶煤岩样品的基础上,通过系列实验分析手段,研究了早期煤化作用过程中低煤阶煤储层的物质组成、孔隙-裂隙系统、储层物性等方面的变化规律。在煤化作用早期阶段,孔隙类型的变化主要表现为原生孔的破坏与收缩、后生孔和割理的形成。储集空间由以发育大孔和中孔为主的孔隙型分布,逐渐变化为以发育孔隙、裂隙为主。从褐煤到低煤阶烟煤,随着煤化作用进行,煤储层的孔隙度呈现出先快速降低之后缓慢增高的趋势;渗透率整体呈现增高的趋势;甲烷的吸附能力逐渐增强,吸附气比例逐渐增加。在详细描述“第一次煤化作用跃变”前后低煤阶煤储层的孔隙类型、孔径分布、孔隙度、渗透率及气体赋存方式的基础上,提出了褐煤与低煤阶烟煤储层评价参数权重与隶属度的差异化处理方法,以期为中国低煤阶煤层气的勘探开发提供科学依据。The first coalification jump significantly changes the physical properties of coal reservoirs in the early stage of coalification.In view of this dynamic change characteristic of physical properties and in order to determine the evaluation parameters and standards of the favorable low-rank coal reservoirs before and after the jump of coalification,the material composition,pore-fracture system and reservoir physical properties of low-rank coal reservoirs in the early stage of coalification were studied by means of a series of experimental analysis methods on the basis of systematically collecting low-rank coal samples from major basins in China.In the early stage of coalification,the changes of pore types are mainly characterized by the destruction and contraction of primary pores,and the formation of secondary thermogenic pores and cleats.The reservoir space is mainly distributed by macropores and mesopores,and gradually changed to pores and fractures.From lignite to low-rank bituminous coal,with the progress of coalification,the porosity of coal reservoir shows a trend of first decreasing rapidly and then increasing slowly,and the overall permeability shows a trend of increase.The adsorption capacity of methane and the proportion of adsorbed gas increases gradually.Based on the detailed description of the pore type,pore size distribution,porosity,permeability and gas occurrence mode of the low-rank coal reservoir before and after the first coalification jump,this paper proposes the differential treatment method for the weight and membership degree of evaluation parameters between lignite and low-rank bituminous coal reservoir,aiming to provide a scientific basis for the exploration and development of low-rank coalbed methane in China.

关 键 词：低煤阶煤 煤化作用跃变 褐煤 低煤阶烟煤 储层物性 评价参数 

分 类 号：TE122.2[石油与天然气工程—油气勘探]