摘要
针对裂缝性油藏堵水成功率低、堵剂漏失严重且容易误堵的问题,研制了一种凝胶颗粒类堵剂,该堵剂通过凝胶颗粒在地层下的二次交联进行堵水。以丙烯酰胺(AM)和不稳定易分解酯类单体J-1为主要原料,通过本体聚合的方法合成凝胶颗粒,由于J-1中含有双键结构使其聚合成具有三维网状结构的凝胶颗粒;凝胶颗粒和二次交联剂J-2在地层下再次交联形成高强度凝胶体。凝胶颗粒成胶时间随J-1加量不同其分解时间不同,使得颗粒成胶时间可控。堵剂成胶时间为1~4 d,凝胶颗粒质量分数为1%~3%,初始黏度接近注入水黏度,在油相中基本不成胶,在水相中能够形成高黏度凝胶体,在高矿化度下能够形成黏度220000 mPa·s以上的高强度凝胶;在70℃条件下,90 d内黏度变化较小,性能保持良好,具有良好的抗盐性和热稳定性。填砂管实验结果表明,堵水体系突破压力在31.25 MPa/m以上,封堵率在92%以上,具有很好的封堵性能。
Aiming at solving the problems such as low success rate of water plugging and serious leakage of plugging agent for fractured reservoirs,a gel particle plugging agent is developed,which plugs water through secondary crosslinking of gel particles under stratum.The gel particles are synthesized by bulk polymerization with acrylamide(AM)and unstable decomposable ester monomer J-1 as the main raw materials.Because J-1 contains double bond structure,the polymerized gel particles possess three dimensional network structure.High strength gel is formed under stratum through crosslinking between the gel particles and secondary crosslinking agent J-2.The gelation time of gel particles is different with the amount of J-1 added,and the time of decomposition is also different,which makes the gelation time of the particles controllable.This water shutoff system needs 1-4 days in gelation,the contents of gel particles are in the range of 1%-3%,and the initial viscosity approaches to the viscosity of the injected water.There is hardly gel being formed in the oil phase,while high viscosity gel can be formed in the water phase.The gel with a viscosity of above 220000 mPa·s-1 can be obtained under a high mineralization degree.In a 70℃surrounding,the gel has changed a little in viscosity in 90 days,and kept good performance,good salt resistance and thermal stability.The experimental results via sand filled pipes show that the system exhibits a breakthrough pressure of above 31.25 MPa·m^-1 and a plugging rate more than 92%,representing a good plugging performance.
作者
张顶学
黄译萱
孙意
ZHANG Ding-xue;HUANG Yi-xuan;SUN Yi(College of Petroleum Engineering,Yangtze University,Wuhan 434000,China)
出处
《现代化工》
CAS
CSCD
北大核心
2020年第10期137-140,共4页
Modern Chemical Industry
基金
国家自然科学基金项目(51504038)。
关键词
凝胶颗粒
二次交联
本体聚合
选择性堵水
gel particles
secondary crosslinking
bulk polymerization
selective water plugging
