煤储层酸化增渗影响因素及酸化压裂选井原则

Coal Reservoir Acidification Permeability Enhancing Impact Factors and Acidification Fracturing Well Selection Principle

为了明确酸化压裂对煤储层增产改造的适应性,通过煤样碳酸岩含量测试和酸液浸泡前后渗透率实验,得到了酸液对煤样渗透率的影响规律,提出了酸化压裂工艺选井原则并开展现场实施。结果表明,6块煤样在酸液中浸泡后渗透率增加了1.34~11.73倍,表明酸化压裂确实能够有效提高煤样渗透率,且碳酸盐矿物含量越高,渗透率增加倍数越大,酸化效果越好。酸化压裂应该选择碳酸盐含量大于1%,黏土矿物含量低于2%,含气量大于16m^3/t,储层渗透率为0.1~0.2mD的井,才能获得较好的效果。实践表明研究内容对煤层气井酸化压裂增产工艺实施具有指导意义。

To clarify adaptability of the acidification fracturing on coal reservoir production increasing reform,through coal sample before and after carbonate minerals content test and acid liquor soak permeability test worked out acid liquor impact pattern on coal sample permeability,then put forward acidification fracturing technology well selection principle and carried out site practices.The result has shown that six coal samples after soak in acid liquor,the permeability has increased 1.34~11.73 times,indicated acidification fracturing can improve coal and rock permeability effectively,while the higher the carbonate minerals content,the larger the permeability increased times,the better the acidification effect.Acidification fracturing should select wells with carbonate minerals content larger than1%,clay minerals content lower than 2%,gas content larger than 16 m^3/t and reservoir permeability 0.1~0.2 can acquire better effect.The practices have shown that the studied results have guiding significance in CBM well acidification fracturing production increasing technology implementation.