沁水盆地煤岩高温高压实验变形分析

ANALYSIS OF COAL ROCK DEFORMATION AT HIGH-TEMPERATURE AND HIGH-PRESSURE EXPERIMENTAL CONDITIONS

沁水盆地煤岩样品高温高压变形实验结果表明,不同煤级的煤岩,在其相同的实验条件下,煤岩强度 即表现出一致性又显现出差异性。而在不同的实验条件下,对于煤岩强度的影响,温度效应要高于压力效应。在 一定的温压条件下(300℃/300MPa),中煤级煤应力强度低于高煤级煤的应力强度;高煤级煤惰质组含量低的煤 岩应力强度最小。煤岩的脆—韧性转变发育于200℃/200MPa和300℃/300MPa之间,此时煤储层的孔隙率在 减小,同时产生了一些裂隙,增加了煤储层的渗透性。文章试图结合煤岩显微组分、渗透率和比表面积等测试结 果,探讨煤岩变形与储集性能的关系。

The deformation experimental (at high-temperatures and high-pressures) results of the coal rock samples collected from Qinshui Basin indicated that the coal rock strengths of different ranks were of both conformity and diversity under the same experimental conditions; the effect of temperature on coal rock strength was higher than that of pressure under different experimental conditions; the stress strength of medium rank coal was lower than that of high rank coal at a certain temperature and pressure (300°C/300 MPa); the stress strength of high rank coal rock with low inertinite content was minimum; and the brittle-tough transition of coal rock developed between 200°C/200 MPa and 300°C/300 MPa, and, at this moment, the porosity of coal reservoir decreased but a certain number of fractures began to form, thus enhancing the permeability of coal reservoir. In the paper, the relation between coal rock deformation and its storage behaviour is discussed in combination with the test results of the maceral, permeability and specific surface of the coal rocks.