An effective stress calculation formula for coal containing gas is proposed coupling with the swelling stress of gas adsorption in the effective stress principle for porous media.
首先在多孔介质的有效应力原理中引入瓦斯吸附的膨胀应力，推导出了适用于含瓦斯煤岩的有效应力计算公式。
2
Blockage of coal seams by fracturing fluids (FFs) and swelling of coal matrix owing to FF adsorption are discussed and considered to be the basic factors for coalbed permeability damage.
讨论了伤害煤层渗透率的两大因素：压裂液堵塞煤层割理； 煤基质吸附压裂液而膨胀。
3
This paper mainly deals with the correlativity between Gray-king Assay coke type(GAC) and free swelling index(FSI) on the gas coal.