膨胀型自悬浮支撑剂的制备及性能评价

Preparation and Performance Evaluation of Intumescent Self-suspending Proppant

为了提高支撑剂在清水中的悬浮性能、改善支撑剂在裂缝中的分布、简化压裂施工工艺、提高压裂措施产量,通过在支撑剂表面进行硅烷偶联改性引入双键,再通过接枝聚合反应将膨胀树脂接枝在支撑剂表面,制得膨胀型自悬浮支撑剂,研究了硅烷偶联剂种类及用量、单体比例、单体浓度对自悬浮支撑剂膨胀性能的影响。结果表明,在支撑剂、丙烯酰胺(AM)、丙烯酸(AA)、N,N'-甲叉基双丙烯酰胺(MBA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)质量比为600∶71∶40∶1∶8,硅烷偶联剂加量1%,引发剂加量1‰,单体(AA、AM、AMPS、MBA)质量分数20%,反应温度30℃的条件下制得的自悬浮支撑剂在清水中的膨胀倍数为1.5~5;支撑剂膨胀性能受阳离子浓度的影响,影响强弱顺序为Mg^(2+)>Ca^(2+)>K^+>Na^+;压裂模拟结果表明,自悬浮支撑剂的运移铺置效果好于常规支撑剂,其支撑裂缝半长为119.2 m,比常规支撑剂提高24%。

In order to improve the suspension performance of proppant in water, improve the distribution of proppant in cracks, simplify the fracturing construction process and improve the production of fracturing measures, the double bond was introduced to the surface of conventional proppant by using silane coupling agent, then expansion resin was grafted onto the surface of proppant by aqueous graft polymerization to obtain self-suspending proppant. The effects of species and dosage of silane coupling agent, monomer ratio and concentration on the swelling performance of self-suspending proppant were studied. The results showed that under the reaction condition of 600： 71 ： 40： 1 ： 8 mass ratio of proppant, acrylamide （AM）, acrylic acid （AA）, N, N＂-methylene bisacrylamide （MBA） and 2-acrylamido-2-methylpropanesulfonic acid （AMPS）, 1% silane coupling agent, 1‰ initiator, 20% monomer （AA, AM, AMPS, MBA）, 30 ℃ reaction temperature, the expansion ratio of synthesized suspension proppant in water was 1.5-5. The cation concentration had effect on the expansion property of self-suspending proppant. Four cations were arranged according to their influence on expansion property in following order： Mg^2＋〉Ca^2＋〉K^＋〉Na^＋. The fracturing simulation results showed that the migration effect of self-suspending proppant was better than that of conventional proppant, and the support fracture half length was 119.2 m which was higher than that of conventional proppant by 24%.