适合中深层稠油油藏的两亲性稠油乳化降黏剂的制备及性能评价

Preparation and performance evaluation of amphiphilic emulsified viscosity reducer for medium⁃deep heavy oil reservoirs

为了有效降低稠油黏度,进一步提高稠油油藏热采开发后的采收率,以甲基丙烯酰胺MAA、二甲基二烯丙基氯化铵DMDAAC和有机硅表面活性单体T-Si为原料,制备了一种适合稠油油藏化学降黏开采用的MDT-1型两亲性稠油乳化降黏剂,并对其结构进行了表征,评价其综合性能。结果表明:当MDT-1型乳化降黏剂质量浓度为5 g/L时,对目标稠油样品的降黏率可以达到99.22%;对目标稠油的静态洗油率可以达到68.9%;注入1 PV质量浓度为5 g/L的MDT-1型乳化降黏剂后,油藏采收率可比水驱阶段提高37.08百分点;MDT-1型乳化降黏剂与稠油所形成的油水乳状液稳定性较差(120 min脱水率大于80%),乳化降黏后不会增加破乳脱水的工作难度。MDT-1型乳化降黏剂具有良好的界面活性、润湿性、降黏性、驱油性,且洗油效果较好,能够进一步提高稠油油藏热采采收率。研究成果对中深层稠油油藏的高效开发具有一定的指导意义。

In order to effectively reduce heavy oil viscosity and further improve recovery factor after thermal recov-ery of heavy oil reservoirs,taking methylacrylamide(MAA),dimethyldiallylammonium chloride(DMDAAC)and organosilicon surfactant monomers(T-Si)as raw materials,amphiphilic emulsified viscosity reducer MDT-1 for chemical viscosity reduction of heavy oil reservoirs is prepared with its structure characterized for comprehensive performance evaluation.The results show that MDT-1 with mass concentration of 5 g/L gets viscosity reduction rate of 99.22%and static oil washing rate of 68.9%of target heavy oil sample.After injecting 1 PV MDT-1 solution with mass concentration of 5 g/L,recovery factor of reservoirs is increased by 37.08 percentage points of water drive stage.Oil-water emulsion formed by emulsified viscosity reducer MDT-1 and heavy oil has poor stability(dehydra-tion rate in 120 min is>80%),without increasing difficulty of demulsification and dehydration treatment after emul-sified viscosity reduction.Emulsified viscosity reducer MDT-1 further enhances thermal recovery of heavy oil reser-voirs for its high interfacial activity,wettability,viscosity reduction,oil displacement performance,and good oil washing effect.The research results have certain guiding significance for the efficient development of medium-deep heavy oil reservoirs.