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利用沁水东北地区高煤级烟煤物性、力学、声学及薄片等分析资料对煤储层成岩作用特征与力学响应间关系进行了探讨,主要包括:压实作用与应力加载间关系;溶蚀作用及裂缝与力学响应间关系;脉体—蚀变矿物与有效应力系数α、屈服应力及动力学参数间关系。结果表明:该区煤层经历了较强压实及变质作用,压实作用对煤储层纵向物性及强度变化具有一定影响;区内煤岩发育的微裂缝往往伴随一定溶蚀,未充填溶蚀孔缝及张性缝往往导致煤岩三轴强度及弹性模量降低,泊松比升高;有效应力系数α、屈服应力及部分动态力学参数与煤岩中方解石脉体及蚀变矿物含量或填充程度具有较好对应关系。随着煤岩中脉体及蚀变矿物填充程度的增加,煤岩非均质性加强,有效应力增加,渗透性降低,由此可以利用力学参数响应特征对煤岩孔、渗、成岩、裂缝等方面进行综合研究,从而制定合理煤层气储改、排采开发方案。
The relationship between the diagenesis characteristics and mechanical response of coal reservoirs is discussed based on the analysis of physical, mechanical, acoustic and flake properties of high rank bituminous coal in the northeastern Qinshui area, including: the relationship between compaction and stress loading; Fracture and mechanical response; relationship between vein-altered minerals and effective stress coefficient α, yield stress and dynamic parameters. The results show that the coal seams in this area experienced strong compaction and metamorphism, and the compaction has certain influence on the vertical physical properties and strength of the coal reservoirs. The micro-cracks developed in coal and rock in the area tend to be accompanied by some dissolution and unfilled dissolution pores And Zhang seam often lead to the decrease of the triaxial strength and elastic modulus of coal and rock, and the increase of Poisson’s ratio. The effective stress coefficient α, yield stress and some dynamic mechanical parameters and the calcite veins and alteration mineral content or filling degree Have a good correspondence. With the increase of the filling degree of vein body and alteration mineral in coal, the heterogeneity of coal and rock is strengthened, the effective stress is increased and the permeability is decreased, so coal rock pores, seepage, diagenesis, cracks and the like can be utilized by the response of mechanical parameters A comprehensive study, so as to formulate a reasonable coal bed gas storage and reform, drainage development program.