海上S油田稠油乳化降黏技术

Viscosity Reducing Technology of Heavy Oil by Emulsifying in Offshore S Oilfield

王大威 张健 崔盈贤 谭业邦

WANG Dawei. ZHANG Jian. CUI Yingxian. TAN Yebang

针对稠油黏度高，单纯聚合物驱亲和原油能力差，驱替携带效率低，提高采收率程度低等问题，本文采用新型聚合物型降黏剂RH327 对海上S油田稠油进行降黏实验，评价了其乳化浓度、乳化类型、聚集形态、界面活性、润湿性、稳定性、静动态吸附能力等性能，在此基础上通过物理模拟驱油实验，形成可有效提高原油采收率的聚合物型降黏剂驱油体系。结果表明，降黏剂RH327 在油藏环境条件下，在较低浓度下即具有较强乳化活性和界面活性，浓度1.2 g/L、油水比为50∶50 时对稠油的降黏率达94.7%；同时具有较快的乳化速度和较强的稳定性，乳化速度为0.17 mL/min；RH327 在油砂和岩心中吸附量较小，RH327 在较高浓度（2.0g/L）下的油砂的静态吸附量仅为3.4 mg/g，浓度为1.6 g/L 的RH327 溶液在注入2.5 PV时渗透率为2756.15×10-3 μm2的人造岩心达到饱和吸附，饱和吸附量为160 ug/g 左右；物理模拟驱油实验结果表明，在保证主体降黏剂段塞在0.3 PV条件下，前后用聚合物段塞（两亲丙烯酰胺聚合物ICGN，使用浓度1750 mg/L，0.06 PV）进行保护，可在水驱（35.72%）基础上提高采收率17.3%，在S油田高含水阶段具有较好的应用前景。图6 表3 参18

Aiming at the problem that heavy oil have high viscosity，while the pure polymer flooding has poor affinity with crude oil and the displacing efficiency and enhancement of oil recovery is low，the viscosity reduction experiments of the heavy oil in offshore S using a polymer emulsifier RH327 was carried out，and the emulsion type，the emulsion concentration，the aggregation morphology，the wetting ability，the stability and the static/dynamic adsorption capacity were evaluated under reservoir conditions. On the basis，the flooding performance of RH327 were evaluated through physical simulation，and novel polymeric emulsifier system that could enhance oil recovery substantially was established. The results showed that，at lower concentrations（1.2 g/L），the viscosity reducer RH327 had strong emulsifying activity under the reservoir environmental conditions，the viscosity of crude oil could reduced by 94.7% at oil-water ratio of 50∶50；at the same time，RH327 also had fast emulsification speed and strong emulsification stability，the emulsification rate being of 0.17 mL/min. The static adsorption of RH327 at higher concentrations of 2g/L in the oil sands was only 3.4 mg/g，the saturated adsorption of the artificial core with the permeability of 2756.15×10-3 μm2 could be attained after injecting 2.5 PV RH327 solution with the concentration of 1.6 g/L，the saturated adsorption capacity being of 160 ug/g. Physical simulation results showed that when main viscosity reducing agent slug was 0.3 PV and polymer protective slug（amphiphilic acrylamide polymer ICGN）with concentration of 1750 mg/L and slug size of 0.06 PV was conducted，the RH327 solution could enhance the oil recovery by 17.3% based on the water flooding（35.72%）