胜利油田金17 块稠油-水乳化特性及其 对乳化驱油的影响.

The development effects of heavy oil reservoirs after water flooding become poor due to the serious emulsification of produced liquid and reduction of formation fluidity in Block Jin17 of Shengli Oilfield. Therefore, the emulsification characteristics of heavy oil and water were studied through emulsification state analysis, viscosity, and rheology testing, oil-water interfacial tension (IFT) testing, etc., and the flow characteristics of emulsified heavy oil were analyzed. Then, the re-emulsification characteristics of emulsified heavy oil were studied by analyzing the emulsification state, droplet size, viscosity, and viscoelasticity of emulsions formed by emulsification oil flooding agent and W/O emulsion. Finally, the re-emulsification mechanisms of emulsified heavy oil were analyzed, and the idea of emulsification oil flooding method was provided. The results show that emulsification has a serious effect on the viscosity of heavy oil emulsions. Under the reservoir temperature of 60 °C, the viscosity, viscosity modulus, and IFT of W/O emulsions with water content of 60% are 11.9, 13.49, and 2.49 times that of dehydrated heavy oil, respectively. Moreover, the fluidity of W/O emulsions in the porous media is seriously restricted due to its stronger non-Newtonian characteristics, the viscosity increased exponentially, the viscous modulus increased significantly, and IFT increased rapidly when the water content is higher than 40%. W/O/W multiple emulsions are formed when emulsified heavy oil and emulsification oil flooding agents are reemulsified. Moreover, the droplet size, viscosity, and viscoelasticity of the emulsions increase with the increment of initial water content in W/O emulsion. When the initial water content of W/O emulsion is 60%, the droplet sizes of emulsions formed by emulsification oil flooding agents LPA, HPF, and SDS and W/O emulsion are 91.3, 40.6, and 27.5 μm, respectively. Compared with the emulsions formed with dehydrated heavy oil, the droplet sizes are 7.9, 4.0, and 2.2 times, respectively. This indicates that the emulsification of formation water/injection water and heavy oil has a great influence on enhanced oil recovery of heavy oil by emulsification oil flooding agents. Therefore, strengthening the ability of emulsification oil flooding systems to penetrate oil film and replace the adsorption of active substances in heavy oil on the oil-water interface is the focus of subsequent research and development of emulsification oil flooding systems and construction method design. [ABSTRACT FROM AUTHOR]

胜利油田金17 块稠油油藏采用水驱后采出液乳化严重, 地层流动能力降低, 导致开发效果变差。通过乳化状态分析、黏 度和流变性测试、油水界面张力测试等研究稠油和水的乳化特性, 分析乳化稠油的流动特性; 通过对油田常用的乳化驱油剂与 W/O型乳状液再乳化形成乳状液的乳化状态、粒径、黏度和黏弹性分析, 对乳化稠油再乳化特性进行了研究; 分析乳化稠油再 乳化机理, 并对乳化驱油研究提供了思路。结果表明：乳化严重影响稠油乳状液的黏度, 在油藏温度 (60 ℃) 条件下, 含水率为 60%的W/O型乳状液, 其黏度、黏性模量和油水界面张力分别是脱水稠油的11.9 倍、13.49 倍和2.49 倍。当含水率高于40% 时, 非牛顿特性变强、黏度开始呈指数式增大、黏性模量增大显著、油水界面张力迅速增大, 严重制约了其在孔隙介质中的流动 性。当乳化稠油与乳化驱油剂再乳化时, 形成W/O/W型多重乳状液。乳状液的粒径、黏度和黏弹性随着W/O型乳状液中初 始含水率的升高而增大。当初始含水率为60%时, 乳化驱油剂LPA, HPF 和SDS 与W/O型乳状液再乳化后形成乳状液的粒径 分别为91.3, 40.6 和27.5 μm。相比于它们与脱水稠油形成的乳状液, 粒径分别增大7.9 倍、4.0 倍和2.2 倍。说明地层水/注入水 与稠油的乳化对乳化驱油剂提高稠油采收率有很大的影响。因此, 强化乳化驱油体系穿透油膜和取代稠油中活性物质在油水 界面上吸附的能力是后续乳化驱油体系研发和施工工艺设计的重点。 [ABSTRACT FROM AUTHOR]