煤储层中裂隙充填物的特征及其研究意义

煤储层中裂隙充填物主要是围岩裂隙中的水溶液与煤中有机显微组分热解产生的以气相为主的流体相互作用的产物,它们相互作用带的位置对煤层气藏封闭保存条件的影响至关重要。若无机充填物仅发育于封闭围岩之中,则其相应的煤层气藏的封闭条件好,含气饱和度高;反之,若在煤储层的裂隙中发育大量无机充填物,则煤层气藏的封闭条件差,含气饱和度低。此外,充填物还堵塞了煤储层中裂隙的通道,使渗透率降低。 

THE CHARACTERISTICS OF THE FRACTURE FILLINGS IN COAL RESERVOIRS AND ITS STUDY SIGNIFICANCE

The fracture fillings are mainly the products resulted by the interactions between the water solution in the fractures of surrounding rocks and the fluid in the coal resrvoirs,and the latter was generated by the pyrolysis of organic macerals and dominated by the gas phase.The location of interaction between both of them had a very important affect on the trap and preservative conditions of CBM pool.The trap condition of CBM pool was good and the gas saturation was high if the inorganic filling was developed only in the surrounding rock;otherwise,the trap condition of it was bad and the gas saturation was low if a great of inorganic filling had developed in the fractures of coal reservoirs.In addition,the inorganic filling had stopped up the fracdture passages in coal reservoirs and had reduced the permeability.