新型自悬浮支撑剂性能评价与现场应用

针对常规胍胶压裂液压裂时残渣对低渗油藏储层伤害大、配液流程复杂、作业强度大的问题,以覆膜石英砂为支撑剂核心、膨胀性树脂为悬浮性材料制备了自悬浮支撑剂,对其性能进行了评价,并开展了清水压裂试验。室内性能评价结果表明:自悬浮支撑剂的理化性能与陶粒、覆膜石英砂相当,导流能力与覆膜石英砂相当,可以在140 s内形成悬浮状态,在110℃下静置120 min不会分层;在540 s-1剪切速率下,剪切10 min后,稳定时间为27 min,而且破胶后胶液的黏度只有4 mPa·s。该自悬浮支撑剂在6口井的清水压裂中进行了应用,施工成功率100%,达到了国内常规冻胶压裂液加砂压裂的技术指标。研究结果表明,自悬浮支撑剂可以满足清水压裂施工的需求,能达到节省胍胶、简化配液流程、减轻储层伤害的目的,具有良好的经济效益和广阔的应用前景。 

Property Evaluation and Field Applications of a New Self-Suspending Proppant

When conventional guar fracturing fluid is used for fracturing, low-permeability reservoirs are significantly damaged by its residues, the flow chart of fluid preparation is complex and the operation intensity is high. In order to solve these problems, a self-suspending proppant was prepared with coated quartz sand as the core and swelling resin as the suspending material. Later, its properties were evaluated and riverfrac tests were carried out on it. Laboratory property evaluation results demonstrated that the self-suspending proppant was equivalent to ceramic and coated quartz sand in terms of physical and chemical properties and to coated quartz sand in terms of flow conductivity. Suspension state appeared within 140 s and no stratification occurred at 110℃ after it was rested for 120 min. It was stable for 27 min after being shorn for 10 min at the shear rate of 540 s-1, and its viscosity after break was only 4 mPa·s. This self-suspending proppant was applied in 6 wells for riverfrac with success rate of 100%. Obviously, it reached the technical indictors of domestic sand fracturing with conventional gel fracturing fluid. It was shown that the self-suspending proppant could meet the operation requirements of riverfrac. Based on results, guar consumption was reduced, the flow chart of fluid preparation was simplified and reservoir damage was mitigated. Therefore, applying the new approach could result in better economic returns.