Experimental Study On Improving Oil Flow Of Shaft With Oil - Bearing Foam

There are many methods to decrease viscosity of heavy oil and improve it’s mobility. Among which, forming oily foam to improve the heavy’s mobility is a new one. When thin oil is in short and the economical value of adding thin oil to decrease viscosity becomes low, this method provides an economical and useful supplement to improve the flow ability in the well bore. As oily foam is gas-liquid two-phase flow, conditions in the well bore is complex and there are many influencing factors. This thesis aims at characteristics of heavy oil and the practical situation in the7th block in Tahe oil field, made a number of studies as followed.1. Aimed at highly mineralized formation brine in the target block, confected foaming agent named S156. The results showed that SI56system had good adaptability in23×104salinity brine, it’s FCI could be as high as3755.9mL-min when the agent concentration was0.2%.2. Studied affecting factors under normal temperature and normal pressure. Summarized conditions which was best for oily foam production and stability by comparison. The results showed that:crude oil viscosity18620mPa·s, oil-water ratio1:2, concentration of S1560.7%, long stirring period, suitable shearing rate and relatively low temperature are preferable conditons for oily foam production and stability. Based on experiments under normal temperature and normal pressure, simulated the temperature and pressure in the well bore, dissolved gas into liquid phase to confect reservoir oil. Through observing foam property after decompression, preferred conditions were concluded. While the pressure in the well bore was high enough, the pressure of adding foaming agent should higher than20MPa. Nitrogen was suitable than air and carbon dioxide. Sharper decline of pressure was better.3. With physical simulation experiments, measured oily foam apparent viscosity distribution along the depth of the well-bore and the viscosity-decreasing efficiency compared with crude liquid, and compared liquid outlook form the end of the pipeline. The results shoued that:while the depth decrease, the apparent vososity of oily foam increase because of the temperature declination. In the depth of1064mN1596m and2128m, the viscosity-decreasing efficiency were respectively57.98%、79.48%and87.10%. Results of liquid outlook comparition showed that:oily foam and crude liquid were quite different in their external form, oil phase、gas phase and water phase could mix sufficiently in pipe line, the goal of increase the flow ability in the well bore was achieved.Research achievements of this thesis has positive significance to the heavy oil recovery in the7th block in Tahe oil field, and has provided useful references for similar researchs which aim to improve heavy oil flowability in the well bore.