海水基速溶调剖体系的研制与应用

Preparation of brine-based instant profile control system and its application

基于胜利埕岛油田的开发特点,研制一种海水基速溶调剖体系.该体系主要由分散聚合法制备的聚丙烯酰胺乳液、甲阶段酚醛树脂交联剂和除氧剂等组成.实验表明,该调剖体系可用注入海水直接配制,溶解速度快(25℃下搅拌15～20min即可充分溶解),成冻时间可控,对环境友好.通过室内实验优选出调剖体系配方,并设计满足现场施工要求的3个调剖剂配方,实现对储层不同空间的有效封堵.岩心模拟表明,该调剖体系能对高渗透层形成有效封堵,耐冲刷性好、热稳定性强,是一种选择性堵剂.现场试验井注水剖面得到有效改善,油井日增油14.6t,综合含水率下降4.1%,效果明显.该海水基速溶调剖技术可在海上油田推广应用.

Based on the developing characteristics of Chengdao offshore oilfield in Shengli,a new type of brine-based instant profile control system was studied,which consists of polyacrylamide latex synthesized by dispersion polymerization,phenolic resin crosslinker,and oxygen scavenger. The profile control system can be dissolved directly in seawater,which can be dissolved absolutely in 15~20 minutes at 25 ℃,and has no pollution to the environment. The effect of the concentration of polymer and crosslinker,salinity,temperature,pH value and shearing to the performance of the profile control system were discussed,the formulas with different gelation time and gel strength were optimized to plug the reservoir effectively. The physical simulation test proves that it could plug the high permeability zone effectively,with fine stability and it's a type of selective profile control agent. Water injection profile in pilot testing wells was improved so effectively that oil output increased by 25.3 t/d and general water cut decreased by 4.1%. Thus this technique can be generalized in offshore oilfields.