持久疏水超低密控水微球的制备和性能

Preparation and Properties of Long-term Durable Hydrophobic Ultra-low-density Water Control Microspheres

具有持久疏水能力的控水型超低密度支撑剂是应对石油开采中高含水井或压裂施工中后期产出液高含水问题的关键材料。首先制备了结构致密和尺寸可控的轻质高强交联聚苯乙烯(CPS)微球,再通过氟树脂在CPS表面进行疏水覆膜改性,获得了疏水能力强且持久的、兼具高强度和超低密度的智能控水(LWC)微球。通过接触角测量仪监测LWC微球的疏水性和疏水稳定性,通过压力试验机和裂缝导流能力测试仪分别评价LWC微球的抗压强度和其对水、油的导流能力。结果表明:LWC微球的表观密度约1.047 g·cm^(-3),60 MPa闭合压力下的破碎率低至2.25%,表面静态水相接触角约135.9°;LWC在有机清洗剂和煤油中热处理48 h,乃至在土酸和10%的盐酸中热处理30 d后,该接触角仍保持在80%以上,疏水能力稳定;纯水在100 cm的LWC填砂管中的渗透率较常规陶粒填砂管降低了86.1%,在50 MPa以下的闭合压力下,油测裂缝导流能力显著高于水测导流能力。LWC表现出符合设计的优异的导油阻水能力,具备作为智能控水支撑剂或封隔体填充颗粒的极大潜力,有利于油气增产提质。

Long-term durable hydrophobic and ultra-low-density water control proppants are important to deal with the problems of high water content in oil exploitation which is more serious at the late stage of hydraulic fracturing construction. In the paper,long-term durable hydrophobic ultra-low-density and highstrength water control( LWC) microspheres were proposed and prepared after compact and size-controllable ultra-low-density and high-strength crosslinked polystyrene( CPS) microspheres were prepared,and a proper fluorine resin for the CPS was proposed. The hydrophobicity and hydrophobicity stability of the LWC microspheres were monitored by a contact angle tester,and the compressive strength and conductivity of LWC microspheres to water and oil were evaluated by pressure tester and fracture conductivity tester respectively. The results show that the apparent density of LWC microspheres is about 1. 047 g·cm^(-3) and the crushing rate is as low as 2. 25% at a closure pressure of 60 MPa. The surface static water contact angle is about 135. 9° which remains above 80% even when the LWC is heated in organic working solution for 48 h,and in mud acid and HCl( 10%) solution for 30 d,demonstrating that the hydrophobicity of the LWC is stable. The permeability of pure water in the 100 cm LWC-filled pipe is decreased by86. 1% compared with that in traditional ceramic-filled pipe,and the measured oil conductivity in the LWC supported fractures is significantly higher than the water conductivity at the closure pressure below50 MPa. The LWC has demonstrated excellent oil conductivity and water blocking ability as designed and has great potential to be used as an intelligent water control proppant or packer filling particles to enhance the yield and quality of oil and gas.