Studies On High-temperature Acidification Gellant Synthesized With Emulsion Polymerization

Acidification of gelled acid is the major stimulation of oil and water wells, and its wide application is sharply increasing in domestic oil fields, especially the deep acidification, so the demand of gelling agent is becoming more and more. In view of the problems of the gelling agent with the water solution polymerization,such as: lower EC, lower molecular weight, non-stabilized performance, non-convenient to the utilization and transportation and so on, in this paper, a kind of gellant for high-temperature acidification, YJN-2, is designed and synthesized. By utilized an inverse emulsion polymerization and oil soluble redox initiator, a terpolymer is synthesized with three monomers which are non-ionic monomer AM, composite cationic monomer H-DMDAAC and anion monomer S-AMPS. By lots of experiments in laboratory, the reaction affecting factors are carefully investigated, and the best reaction conditions and monomer partition are explored; Its molecular structure and characteristic parameters are described by IR, and its mechanism of resisting salts and thermal stability are studied with the molecular structure and component; The performances are comprehensive evaluation in laboratory and the relation to composition and performances are investigated. The evaluaterating results in the laboratory indicate that: the reactant concentration of inverse emulsion polymerization accesses to 40% relatively with the water solution polymerization 8~10%; YJN-2 has high EC and quick speed dissolved capability; With YJN-2 concentration 2% and acid concentration 20%, the viscosity is 27.2mPa·s at 90℃; and the viscosity rate of decline is 22.1% after two hours later at 130℃; It has good thickening capability; In addition, YJN-2 has approved properties in thermal stability, resisting salts, shear stability, compatibility with acid and acid additive, and its performances are steady and its using is convenient. Performances are superior to the capability of domestic gelling agents, for example CT1-9, VY-101 and so on. Now the trial production and pilot tests are running.