沁水盆地典型煤矿区煤的流速敏感性实验及控制机理

发布时间：2018-12-19 16:55

【摘要】：采用沁水盆地3个典型煤矿中、高煤阶煤样,开展了实验室煤样流速敏感性实验,分析了不同流速条件下煤样渗透率的变化规律,建立了煤储层渗透性与流速之间的关系和模型,揭示了中、高煤阶煤储层流速敏感性的控制机理。研究结果表明,煤样渗透率随流速发生变化,且存在一个临界流速。在临界流速之前随着注入流量(或流速)的增加煤样渗透率增加,当流速超过临界流速后,煤样的渗透率随着流体流速的增加反而减少。煤储层流速敏感性主要受控于煤储层物性和煤中速敏矿物。随着煤储层孔隙度、渗透率和流体流量的增高,煤储层速敏损害率按对数函数关系增高。实验煤样黏土矿物占矿物质含量为66.63%~99.89%,主要以高岭石、伊利石为主,存在潜在的速敏伤害,速敏实验结果表明,本区实验煤样存在不同程度的速敏损害,煤样速敏损害程度由弱至中等偏强,临界流速低。随着煤中黏土矿物含量的增加,煤储层速敏损害率也增高。在煤层气井排采过程中,寺河煤矿和西山煤矿煤层气井排采降速应为赵庄煤矿的6倍左右。
[Abstract]:By using the high rank coal samples in three typical coal mines in Qinshui Basin, the velocity sensitivity experiments of coal samples in laboratory are carried out, and the changing law of permeability of coal samples under different flow velocity conditions is analyzed. The relationship and model between permeability and velocity of coal reservoir are established, and the control mechanism of velocity sensitivity of middle and high rank coal reservoirs is revealed. The results show that the permeability of coal sample varies with the flow velocity and there exists a critical velocity. The permeability of coal sample increases with the increase of injection flow rate (or flow rate) before the critical flow rate, and decreases with the increase of fluid flow velocity when the flow velocity exceeds the critical velocity. The velocity sensitivity of coal reservoir is mainly controlled by the physical properties of coal reservoir and the velocity sensitive minerals in coal. With the increase of porosity, permeability and fluid flow rate of coal reservoir, the damage rate of velocity sensitivity of coal reservoir increases according to logarithmic function. The mineral content of experimental coal clay is 66.63% and 99.89%, mainly kaolinite and Illite, and there is potential speed sensitive injury. The results of speed sensitive test show that there are different degrees of speed sensitive damage in coal samples in this area, and the results show that the mineral content of clay is 66.63% and 99.89%, mainly kaolinite and Illite. The damage degree of speed sensitivity of coal samples is from weak to moderate, and the critical velocity is low. With the increase of clay content in coal, the speed sensitive damage rate of coal reservoir increases. In the process of coal bed methane well drainage, the coal bed methane well drainage speed of Sihe coal mine and Xishan coal mine is about 6 times that of Zhaozhuang coal mine.
【作者单位】：中国矿业大学(北京)地球科学与测绘工程学院;山西晋城无烟煤矿业集团有限责任公司煤与煤层气共采国家重点实验室;
【基金】：国家自然科学基金资助项目(41372163) 国家科技重大专项资助项目(2016ZX05067001-006) 山西省煤层气联合研究基金资助项目(2014012001)
【分类号】：P618.11

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