基于改性表面活性剂的煤储层表面物理改性增产机理分析

Mechanism Analysis of Physical Modification and Increasing Production of Coal Reservoir Surface Based on Modified Surfactant

以五里堠煤矿煤样为研究对象,采用表面活性剂压裂液(1.5%KCl+0.05%AN),通过表面张力和接触角测试实验,揭示了煤储层表面物理改性增产机理。研究结果表明:表面活性剂压裂液中的表面活性剂成分能够在煤储层表面进行物理吸附,使得煤储层表面的润湿性、接触角等物理性质发生改变;表面活性剂压裂液能够降低煤层气产出的临界孔径,促进煤层气解吸,实现增解增产;能够降低煤储层孔喉毛细管压力,促进压裂液的排出,有效减少水锁对煤储层渗透率的伤害,实现防水锁增透增产;能够增强煤粉的水润湿性,促进煤粉沉降,有效减少速敏对煤储层渗透率的伤害,实现防速敏增透增产。

We collected the coal sample of Wulihou Coal Mine as the research object, used the surfactant fracturing fluid(1.5%KCl + 0.05% AN), by the experiment that test surface tension and contact angle, revealed the mechanism of increasing production by changing surface physical nature of the coal reservoir. The result showed that: the surfactant components in the surfactant fracturing fluid can be adsorbed physically onto the coal reservoir surface, which changed the physical nature of the coal reservoir surface. Surfactant fracturing fluid can reduce the critical pore size of coalbed methane output, promote coalbed methane desorption, and increase desorption and yield was achieved;it can reduce the pore throat capillary pressure of coal reservoir,promote the discharge of fracturing fluid, reduce the damage of water-lock on the permeability of coal reservoir effectively,increased permeability and yield by preventing water-lock was achieved;it can improve wettability of coal powder, promote coal powder settlement, reduce the damage of velocity sensitivity on permeability of coal reservoir effectively, increased permeability and yield by preventing velocity sensitivity was achieved.