煤岩压裂液动滤失实验研究

Experiment research on fracture fluid dynamic filtration of coal rocks

煤岩压裂液滤失实验目前尚无标准方案,常规油气储层的压裂液滤失实验方法对煤储层不适用,需改进实验方案并提出适用于煤储层的标准方案。基于油气行业标准和煤储层特性,提出了新的煤岩压裂液动滤失实验方法,通过测取清洁压裂液、3%KCl溶液、活性水通过岩心时的滤失情况进行了探索研究,得出了煤岩压裂液滤失的特征:煤岩压裂液滤失量偏大、滤失实验曲线没有明显的分段、初始滤失量有负值的情况。实验结果表明不同类型的压裂液都会对煤储层渗透率造成伤害,相对而言清洁压裂液伤害率较高,在百分之四十左右。

There're no standard programs for coal rocks' fracture fluid filtration experiment at present.Based on the inapplicability of conventional petroleum reservoirs' fracture fluid filtration experiment for coal rocks,the conventional experiment method needs to be modified for the requirements of coal rocks.Based on the oil&gas industrial standard and coal reservoirs' characteristics,this paper proposed a new method for coal rocks' fracture fluid dynamic filtration experiment.Through testing clean fracture fluid,3% KCl solution and conducting a research on the filtration situation of active water when flowing through cores,the characteristics of coal rocks' fracture fluid filtration was obtained as follows: core rocks' fracture fluid filtration loss was relatively large;no subsection appeared in filtration experiment curve;negative value appeared in initial filtration loss.The results showed that different types of fracture fluids could cause damage to the coal rocks' permeability and clean fracture fluid caused relatively high rate of damage at about 40 percent.