酸液溶蚀作用对支撑剂性能的影响

前置酸液加砂压裂是提高致密储层有效动用的技术之一。注入酸液能有效降低储层破裂压力、清洁地层、提高压裂效果,但酸液同时也会与裂缝中的支撑剂接触而发生化学反应,从而降低支撑剂抗压性能,不利于维持较高的导流能力。文中模拟现场压裂施工方案,进行支撑剂酸溶解度测试实验,评价了酸液溶蚀作用对支撑剂抗压强度、导流能力的伤害程度。结果表明:酸液配比对酸溶解度影响最大,其次为接触反应时间;大粒径支撑剂酸溶解度较小,但酸溶蚀作用对大粒径支撑剂抗压强度、导流能力伤害较大;受酸液作用时,石英砂性能相比陶粒支撑剂稳定性好。实验结果为支撑剂的优选、合理控制酸液用量及注入时间等提供了依据。

The effect of acid corrosion on proppant properties

Pre-acid sand fracturing is a technique to improve the effective production of tight rock reservoirs.Acid injection can effectively reduce the fracture pressure of the reservoir and clean the formation to improve the fracturing effect.However,the acid solution will also chemically react with the proppant in the fractures at the same time,which reduces the pressure resistance of the proppant and is not conducive to maintaining a high conductivity.Through simulating field fracturing operation,the proppant acid solubility laboratory experiment was carried out,and the damage to proppant compressive strength and conductivity caused by acid solution corrosion was evaluated.The results show that the proportion of acid solution has the greatest effect on acid solubility,followed by the contact reaction time;the large particle size proppant has a lower acid solubility,but the acid corrosion effect has a greater damage to the compressive strength and conductivity of the large particle size proppant;compared with ceramsite proppant,the performance of quartz sand is better when it is subjected to acid solution.The experimental results provide references for the selection of proppants,reasonable control of the amount of acid solution and the injection time.