考虑吸附滞后效应的煤层气藏物质平衡方程建立及应用

发布时间：2018-01-23 06:22

本文关键词： 煤层气物质平衡方程吸附滞后可采储量采收率　出处：《煤炭学报》2017年10期 　论文类型：期刊论文

【摘要】：目前的煤层气藏物质平衡方程忽略了煤层气吸附-解吸实验中的吸附滞后现象,大多基于煤层气吸附与解吸过程完全可逆的认识所建立的,与实际煤层气藏的排水—降压—解吸开采过程明显不符,从而无法有效指导煤层气藏的开发规划决策或后续开发方案调整。基于煤层气的吸附滞后现象分析,提出了吸附滞后效应概念,进而建立考虑吸附滞后效应影响的煤层气藏物质平衡方程,并将其应用于某煤层气藏的原始地质储量、可采储量和采收率等评价指标预测。实例应用表明,采用物质平衡方法确定煤层气藏地质储量时,若忽略煤层气的吸附滞后效应,采用吸附等温曲线参数将可能会低估煤层气藏的地质储量值却高估采收率值,造成巨大的预测误差;与之相反,采用考虑吸附滞后效应的煤层气藏物质平衡方程确定的气藏地质储量值及平均含水饱和度变化值与实际值之间的误差较小,说明了所构建的煤层气藏物质平衡方程的有效性和正确性,可准确地评价煤层气藏的可采储量和采收率评价指标,对于煤层气藏后续开发规划实施和开发方案调整具有积极的指导作用。
[Abstract]:The current equilibrium equation of coalbed methane reservoir material neglects the phenomenon of adsorption lag in coalbed methane adsorption-desorption experiment. Most of the equations are based on the understanding that the process of coalbed methane adsorption and desorption is completely reversible. It is obviously inconsistent with the process of drainage depressurization and desorption mining of actual coalbed methane reservoir, so it is unable to effectively guide the development planning decision of coalbed methane reservoir or the adjustment of subsequent development plan. Based on the analysis of adsorption lag phenomenon of coalbed methane. In this paper, the concept of adsorption hysteresis effect is put forward, and the equilibrium equation of coalbed methane reservoir material considering the effect of adsorption hysteresis effect is established, and it is applied to the original geological reserves of a coalbed methane reservoir. The prediction of recoverable reserves and oil recovery shows that the adsorption hysteresis effect of coalbed methane is neglected when the method of material balance is used to determine the geological reserves of coalbed methane reservoir. The parameter of adsorption isothermal curve may underestimate the geological reserve value of coalbed methane reservoir but overestimate the recovery factor value, resulting in huge prediction error. On the contrary, the error between the change value of gas reservoir geological reserves and the average water saturation and the actual value is small by using the equilibrium equation of coalbed methane reservoir material considering the adsorption lag effect. It shows the validity and correctness of the material balance equation of coalbed methane reservoir, and it can accurately evaluate the recoverable reserves and oil recovery of coalbed methane reservoir. It plays an active role in guiding the implementation of the subsequent development planning and the adjustment of the development plan for coalbed methane reservoirs.
【作者单位】：中国石油大学(华东)石油工程学院;华北油田山西煤层气勘探开发分公司;
【基金】：国家自然科学基金资助项目(11302265) 中央高校基本科研业务费专项基金资助项目(14CX02046A)
【分类号】：P618.13
【正文快照】： 原位煤层气主要以广义的吸附状态赋存于煤基质孔隙中,包括狭义的吸附(Adsorption)状态、凝聚状态和吸收(Absorption)状态[1]。煤层气吸附作用发生在漫长的煤化作用过程之中,是一个十分复杂的物理化学作用过程,与目前采用排水降压工艺下的煤层气被动解吸作用存在着本质差别,主

【相似文献】