煤层气井压裂裂缝内超级分子膜控煤粉可行性研究

Feasibility study of super molecular film controlled coal powder in fracturing crack of coalbed methane well

针对煤层气井压裂裂缝中的煤粉堵塞问题,提出利用超级分子膜(SMF)在裂缝中形成网状结构,诱导小颗粒煤粉排出,阻止大颗粒煤粉运移,进而提高裂缝的渗透性的方法。以沁水盆地3号煤为对象开展了煤层气井压裂裂缝内控煤粉试验。试验结果表明:SMF中A剂质量分数高于5%,B剂质量分数在2%~9%时能够有效控制煤粉聚集成团,煤粉混合液变清澈;采用SMF驱替后,岩心渗透率提高3~6倍,当SMF组合浓度适中时,岩心渗透率提高6倍以上。驱替后的岩心中,煤粉呈现出明显的团状,驱出来的液体中基本不含煤粉。且液体对煤基质的伤害率在15%以内。表明采用SMF能够有效提高煤粉伤害后的裂缝渗透率,为裂缝内煤粉治理提供了一个新的方向。

Aiming at the problem of pulverized coal clogging in the fractures of coalbed methane wells,it is proposed to use super molecular film( SMF) to form a network structure in the cracks,induce the discharge of small particles of pulverized coal,prevent the migration of large particles of pulverized coal,and thus improve the permeability of cracks. The coal-fired powder test in the fracture of coalbed methane well was carried out with No. 3 coal in Qinshui Basin as a case study. The experimental results show that in the SMF,the concentration of A agent( mass fraction) is higher than 5%,and the concentration of B agent( mass fraction) is 2% to 9%,which can effectively control the coal powder agglomeration,and the coal powder mixture becomes clear. After SMF displacement,the core permeability is increased by three to six times. When the SMF combination concentration is moderate,the core permeability is increased by more than six times. In the core after displacement,the pulverized coal showed a distinct mass,and the liquid that was driven out was basically free of pulverized coal. And the damage rate of the liquid to the coal matrix is within 15%. It shows that the use of SMF can effectively improve the crack penetration rate after pulverized coal damage,and provides a new direction for the treatment of coal powder in the crack.