有机聚合物覆膜对石英砂压裂支撑剂破碎率的影响研究

Research on the Effect of Organic Polymer Coating on the Crushing Rate of Natural Quartz Sand Fracturing Proppants

天然石英砂压裂支撑剂具有成本低、来源广的优点,但存在破碎率高的缺点。如何有效降低天然石英砂压裂支撑剂的破碎率,是拓展其应用的关键问题。覆膜法将有机聚合物包覆在天然石英砂压裂支撑剂表面,制备具有“核壳”结构的覆膜砂,是降低破碎率的重要方法。以70-140目石英砂压裂支撑剂为研究对象,分别以酚醛树脂、环氧树脂、呋喃树脂、聚氨酯为包覆剂,制备了4种覆膜砂,研究了有机聚合物不同种类和不同用量对天然石英砂压裂支撑剂破碎率的影响。结果表明:当采用同种有机聚合物时,在69 MPa闭合压力下,随着有机聚合物用量增加(2%~4%),破碎率先快速降低、后缓慢降低,当有机聚合物用量为6%时,破碎率显著降低;当有机聚合物用量均为6%时,在69 MPa闭合压力下,环氧树脂所得覆膜砂破碎率最低(其值为0.8%),呋喃树脂所得覆膜砂破碎率最高(其值为3.1%),酚醛树脂和聚氨酯所得覆膜砂破碎率居中(其值分别为1.3%和1.8%)。该研究结果可为低破碎率覆膜砂的合成提供一定的理论依据。

The natural quartz sand fracturing proppants has the advantages of low cost and wide source,but has the disadvantage of high crushing rate.How to effectively reduce the crushing rate of the natural quartz sand fracturing proppants is the key problem to expand their application.The film coating method is an important way to reduce the crushing rate by coating an organic polymer on the surface of the natural quartz sand fracturing proppants to prepare the film sands with a “core-shell” structure.The four kinds of the film sands were prepared by using the phenolic resin,epoxy resin,furan resin and polyurethane as coating agents respectively.The effects of different types and amounts of organic polymers on the crushing rate of the natural quartz sand proppants with 70-140 mesh were studied.The results show that when the same organic polymer was used,under the 69 MPa closure pressure,the crushing rate decreases rapidly first,and then slowly with the increases of the amounts of the organic polymer.When the amount of organic polymer is 6%,the crushing rate decreases significantly.When the amount of organic polymer is the same(6%),the crushing rate of the film sands with the epoxy resin is the lowest(0.8%),the crushing rate of the film sands with the phenolic resin is the highest(3.1%),and the crushing rate of the film sands with the phenolic resin(1.3%) and polyurethane(1.8%) is the middle,respectively,under 69 MPa closure pressure.This study can provide a theoretical basis for synthesizing the film sands with low crushing rate.