影响络合铬冻胶成冻因素研究

A study on Influencing Factors of Gelation Behavior of HPAM-Complex Chromium Gel

络合铬冻胶在深部堵水、深部调驱等方面有重要应用前景。本文针对由部分水解聚丙烯酰胺(HPAM)与络合铬(醋酸铬与乳酸铬复配形成铬的多核羟桥络离子)交联而成的络合铬冻胶,采用黏度法和突破真空度法研究了HPAM质量分数(0.1%～0.4%)、交联剂质量分数(0.1%～0.4%)、pH值(5～8)、温度(40～80℃)等因素对络合铬冻胶的成冻时间和冻胶强度的影响。结果表明,随着温度升高,冻胶的成冻时间(包括初冻时间和终冻时间)缩短,冻胶强度增加,当高于60℃时,成冻时间缩短更为明显。HPAM和交联剂的质量分数越大,成冻时间越短。当体系pH=7.0时成冻时间最短,体系呈弱酸性或弱碱性时成冻时间均会延长,且弱酸性时比弱碱性时成冻快,pH值对冻胶强度影响不大。络合铬冻胶的成冻时间与冻胶强度的关系符合常规冻胶所遵循的规律,即成冻时间越短,冻胶的强度则越高。

Complex chromium gels have the broad prospect and potential important applications in the deep water shutoff,profile control and oil displacement.Chromium gel researched in this paper was prepared by the crosslinking reaction of the HPAM and complex chromium ions,obtained by compounding chromium acetate with chromium lactate.The influence of the various factors,such as HPAM mass fraction（0.1%～0.4%）,crosslinker mass fraction（0.1%～0.4%）,pH value（5～8） and temperature（40～80℃）,on gelation time（determined through viscosimetry and strength code method） and gel strength（determined through breakthrough vacuum method） of the HPAM-complex chromium gel were evaluated.The results showed that with the increase of polymer mass fraction,crosslinking mass fraction and temperature,gelation time（including initial gelation time and final gelation time） got shorter and BV increased,at the same time,when the temperature is more than 60℃,the gelation time was greatly reduced.pH value had little effect on gel strength,when pH=7.0,the gelation time was the shortest;while the gelation time got longer under weak acid or weak alkaline conditions.The gelation time and gel strength of complex chromium gel followed the law of the conventional gel,that is,the shorter the gelation time,the greater the gel strength.