沁水盆地南部高阶煤气水相对渗透特征

发布时间：2018-06-01 11:21

本文选题：高阶煤 + 渗流　；参考：《断块油气田》2017年02期

【摘要】：文中通过对比分析核磁共振T2谱分布和基于非稳态法气水相对渗透率测试,研究了沁水盆地高阶煤样的孔隙结构及气水两相渗流特征。结果表明:研究煤样以贫煤、无烟煤为主,其核磁共振T2谱分别对应单峰和双峰2种分布形态;贫煤以微孔和超微孔为主,无烟煤以小孔为主,含部分微孔和超微孔;煤中微孔和超微孔之间的连通性较好,而小孔与微孔和超微孔之间的连通性很差,导致无烟煤中束缚水饱和度很高,有效孔隙度较低;煤体的渗流特征受煤中孔径分布和孔隙连通性的双重影响,孔隙度越大,大孔径孔隙越发育且孔隙连通性越好,则煤体两相共渗区越宽,煤体渗流能力越好。研究煤样相渗特征表现为残余水饱和度高、残余水条件下气相相对渗透率低、气水两相共渗区间窄等特点,揭示了研究区煤层气开发面临着解吸与渗流瓶颈问题。
[Abstract]:In this paper, the pore structure and gas water two-phase flow characteristics of high rank coal samples in Qinshui Basin are studied by comparing the T2 spectrum distribution of NMR and the measurement of relative permeability of gas and water based on the unsteady state method. The results show that the coal samples are based on poor coal and anthracite, and their NMR T2 spectra correspond to 2 distribution patterns of single peak and Shuangfeng, and the poor coal is micro Kong Hechao microporous mainly, anthracite mainly with small pores, containing a part of micropores and ultra micropores. The connectivity between micropores and ultra micropores in coal is good, while the connectivity between micropores and micropores is poor, resulting in high bound water saturation and low effective porosity in anthracite coal, and the pore size distribution of coal and Kong Xilian The greater the porosity is, the larger the porosity is, the more pore pore and the better the pore connectivity, the wider the coal two phase co permeation area is, the better the seepage ability of the coal body is, the characteristics of the coal sample infiltration characteristics are the high residual water saturation, the low relative permeability under the residual water and the narrow interval of the gas water two phase permeability, which reveals the coal in the study area. The development of layer gas is facing the problem of the bottleneck of desorbing and percolation.
【作者单位】：中国矿业大学资源与地球科学学院煤层气资源与成藏过程教育部重点实验室;中国矿业大学低碳能源研究院江苏省煤基CO2捕集与地质存储重点实验室;中国石油华北油田公司山西煤层气分公司;
【基金】：国家自然科学基金项目“深部煤层CO2地质存储与CH4强化开采的有效性理论研究”(41330638)
【分类号】：TE312

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