煤层气压裂用低密度坚果壳支撑剂性能评价与现场试验

Performance evaluation and field test of low-density nut shell proppant in CBM fracturing

延川南煤层气井采用清水石英砂压裂,前期的生产效果显示压裂产生的支撑缝缝长有限,导致施工的加砂难度大,同时,后期的采气效果也不理想。针对此问题,通过室内实验研究,对比评价了常规石英砂支撑剂与低密度坚果壳支撑剂在不同闭合压力下的破碎以及裂缝导流能力。实验结果显示:两者的破碎率均能满足工程要求,在较高闭合应力(35 MPa)条件下,拥有相类似的裂缝导流能力,但低密度坚果壳支撑剂相较于传统石英砂支撑剂价格更加低廉,因此,更能够满足降本增产的目的。该工艺现场试验取得了良好的应用效果。

At present,the clean quartz sand is used in the fracturing of southern Yanchuan CBM wells.According to the production effect in the early stage,the limited length of supporting seam generated by the clean quartz sand fracturing leads to the difficulty of adding sand in the construction,and the gas production effect in the later stage is not ideal.In order to solve this problem,laboratory experiments have been conducted to compare and evaluate the crushing and fracture conductivity of conventional quartz sand proppant and low-density nut shell proppant under different closing pressures.The experimental results show that the fracturing rates of both can meet the engineering requirements.Under high closure stress(35 MPa),they have similar fracture conductivity.However,low-density nut shell proppant is cheaper than traditional quartz sand.Therefore,low-density nut shell proppant is more able to meet the current goal of cost reduction and production increase.The field test of this technology has obtained good results.