新型耐温抗盐堵剂的研究

以丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸/N-十二烷基丙烯酰胺三元共聚物(NKP)为主剂,与改性的聚乙烯亚胺(PEI-GX)反应制备了一种新型耐温抗盐堵剂NKP/PEI-GX;考察了PEI改性率、堵剂的pH、剪切、NKP相对分子质量(M)和地层岩性对堵剂NKP/PEI-GX凝胶性能的影响。实验结果表明,堵剂NKP/PEI-GX成胶时间随PEI改性率的增加而延长;剪切、地层岩性及pH=6～8时对堵剂NKP/PEI-GX凝胶性能的影响不大,pH>9时堵剂发生沉淀;随M(NKP)的增大,堵剂NKP/PEI-GX的凝胶黏度呈增大趋势,但更易于脱水。当M(NKP)=1.6×107、PEI改性率为80%、pH=6～8时,堵剂NKP/PEI-GX在100℃下的成胶时间(30 h)是堵剂NKP/PEI的7.5倍,老化30 d后其凝胶强度可达H级,有望成为在高温、高盐条件下使用的一种新型堵剂。

A Novel Plugging Agent with Heat Tolerance and Salt Tolerance

A novel plugging agent NKP/PEI-GX with heat tolerance and salt tolerance was prepared from acrylamide/2-acrylamido-2-methylpropanesulfonic acid/N-dodecyl acrylamide terpolymer(NKP) and modified polyethyleneimine(PEI-GX).The effects of modification degree of PEI,pH value of plugging agent NKP/PEI-GX,shear,relative molecular mass(M) of NKP and stratum lithology on the gel properties of plugging agent NKP/PEI-GX were investigated.The results showed that the gelation time of plugging agent NKP/PEI-GX increased with the increase of modification degree of PEI;the properties of plugging agent NKP/PEI-GX were not influenced by shear,the stratum lithology and pH 6-8,but the gelation and precipitation occurred when pH was higher than 9.The gel viscosity of plugging agent NKP/PEI-GX increased and it could be easy to dehydrate with the increase of M(NKP).The gelation time of plugging agent NKP/PEI-GX with pH 6-8 prepared from NKP(M=1.6×107) and PEI with 80% modification degree was up to 30 h at 100 ℃,which was 7.5 times of that of plugging agent NKP/PEI,and the gel strength was up to H degree after 30 days aging.Therefore,NKP/PEI-GX is expected to be used as a novel plugging agent under the conditions of high temperature and high salinity.