超稠油蒸汽辅助重力泄油开采不同阶段采出液的性能特征

Performance Characteristics of Produced Fluid in Steam Assisted Gravity Drainage Production of Heavy Oil Reservoir

斯绍雄 王 亮 吴永花 李 雯 乐江华

SI Shaoxiong WANG Liang WU Yonghua LI Wen YUE Jianghua

为揭示超稠油蒸汽辅助重力泄油（SAGD）开采过程不同阶段采出液的性能特征，以新疆油田风城作业区重1井区SAGD循环前期、循环中后期和转抽三个阶段的采出液为研究对象，考察了其组成、乳液类型和稳定性，分析了稳定机理。结果表明，SAGD三阶段采出液均含有较高的沥青质和胶质成分，采出液以O/W型乳液为主，部分为W/O/W型复合乳液。随着SAGD的开采，三阶段采出液的含水率、含砂量和Zeta电位绝对值依次降低。室温下，采出液可以保持稳定，没有油水分离现象，仅形成富油层和富水层。随静置时间的延长，循环前期、循环中后期和转抽采出液的背散射光值（15~25 mm）分别由9%、21%和9.5%增至11%、26.5%和10%，内部颗粒粒径分别由18.9、62.2和169.1 μm降至16.5、49.9和165.3 μm。三阶段分散相粒子的平均迁移速率分别为1.59、1.56和1.55 mm/h。转抽采出液的稳定性指数最小、稳定性最好，循环前期采出液稳定性较差。循环前期采出液稳定机理以扩散双电层为主，转抽阶段采出液则以“沥青质膜”稳定乳液为主。图13表1参13

In order to reveal the performance characteristics of produced fluid in steam assisted gravity drainage (SAGD) production of heavy oil reservoir, the liquid samples produced during three stages of SAGD production were taken as the research objects: early stage of circulating preheating, intermediate stage of circulating preheating and the stage of full production, from Well-Block Zhong-1 in Fengcheng Field, Xinjiang Oilfield. The component, emulsion type and stability of that were studied, and the stability mechanism was discussed. The results showed that the three samples all contained high concentration of asphaltene and resin, and three liquid samples were mixed emulsions composed primarily of O/W emulsion and some W/O/W double emulsion. Besides, the water content, clay concentration and Zeta-potential of the samples decreased along with the SAGD production process. The three stages of SAGD emulsion were stable without phase separation at room temperature, appearing in the form with an oil rich and an aqueous rich phase. With an increase of stewing time, the backscattering value (15—25 mm) of early stage of circulating preheating, intermediate stage of circulating preheating and the stage of full production was increased from 9%, 21% , 9.5% to 11%, 26.5%, 10%, the internal particle size of three stages of SAGD emulsion was decreased from 18.9, 62.2, 169.1 μm to 16.5, 49.9, 165.3 μm, respectively. The average drift rate of the dispersed particles in three stages emulsion was 1.59, 1.56 and 1.55 mm/h. The stability index of full production emulsion was minimum, which indicated that it was the most stable crude. The early stage of circulating preheating emulsion was less stable. The sample during the early circulating preheating stage was stable crucially because of the diffusion double layer, while the sample during full production stage was stabilized predominantly by “asphaltenes-film”.