鲁克沁稠油开采用空气泡沫体系的研究与评价

【作者】 李斌；

【导师】 唐晓东；

【作者基本信息】 西南石油大学 ， 化学工艺， 2014， 硕士

【摘要】 随着稠油油田开采进入中后期,油井综合含水率上升,水驱采收率较低,油田开发难度加大,开采成本升高。空气泡沫驱油综合了空气驱油和泡沫驱油,具有调剖和驱油的双重功能,以其独特的渗流和驱油性能越来越受到人们的重视。鲁克沁油田油藏埋深2000～4800m,油藏温度在80～100℃,地层水矿化度5×104～18×104mg/L,目前主要以水驱开发技术为主,但水驱开发区块油井以凸型水驱特征为主,储层非均质性强,油水粘度比大,水驱指进严重,含水上升快,水驱采收率低。本文针对鲁克沁油藏采用Waring Blender法评选出起泡性能较好的泡沫体系,并对泡沫体系进行耐温、耐盐以及耐油性能评价,同时对泡沫体系中的起泡剂进行油砂静态吸附损失研究；通过填砂管模型对泡沫体系进行封堵能力影响因素探讨,同时研究了空气泡沫驱对提高原油采出程度的贡献。泡沫体系CXF在80℃、矿化度18×104mg/L以及20%的含油量条件下,起泡体积为410mL,析液半衰期为28min,具有较好的起泡性能。填砂管模型实验得到,泡沫体系随着起泡剂浓度升高封堵能力增强,随着气液比增加封堵能力先增加后降低,在气液比1：1时封堵效果最好,随着渗透率增加,封堵能力增强,随着含油饱和度的增加,封堵能力逐渐下降。通过单管驱油实验发现,水驱转入空气泡沫驱后,采收率逐渐升高,采出液含水率下降,空气泡沫驱可提高采收率8.06%,同时含水率从水驱结束时98.12%下降至最低60.34%。双管并联驱油实验结果显示,水驱阶段,高渗管出油较快,水驱阶段高渗管采收率达到53.64%,低渗管采收率为10.94%,在空气泡沫驱阶段高渗管的采收率从水驱的53.64%上升到62.27%,提高了8.63%,低渗管的采收率从10.94%上升到20.31%,提高了9.37%；同时,在空气泡沫驱阶段,由于泡沫的封堵调剖作用,使得总含水率从98.23%下降至最低65.89%。泡沫驱结束后再次注水进行后续水驱,此时水驱使采油量继续增加,最终总采收率达到51.18%。更多还原

【Abstract】 With the development of heavy oil fields, when they came into mid-to-late period of producing, water cut of reservoir rose, the recovery of water flooding became low, the development of oilfield was increasingly difficult, and the mining costs was raised. Integrating air flooding with foam flooding, air foam flooding has a dual function of profile control and displacement. For its specific performance of flow and displacement of reservoir oil, people attached more and more importance to air foam flooding.Now, water flooding is the main development technology of LKQ oil field, whose depth is 2000m-4800m, temperature is 80～100℃ and salinity of the formation water is about 5×104～18×104mg/L. However, the water flooding blocks are convex type, which have a high heterogeneity, high oil water viscosity ratio, serious fingering phenomenon, and fast increase of water cut. It was turned out that the enhanced oil recovery of water flooding was low.In this paper, using the Warring Blender to study a better foam system for LKQ reservoir. Then, for the foam system, temperature tolerance, salt tolerance, and oil resistance were measured, while oil sands static adsorption loss of the foaming agent was investigated. By sand-packed model, influencing factors on blocking ability of the foam system were explored. Simultaneously, the contribution of enhanced oil recovery by air foam flooding was conducted.For the CXF foam system, which the temperature was 80℃, salinity was 18×104mg/L and oil content was 20% reflected the following phenomena that the foaming volume was 410 mL, and half-life was 28min.Thus, the system had good foaming performance. we conducted the blocking ability of the foam system based on sand-packed model, the results shown that: blocking ability will enrich with the increase of concentration of foaming agent; the blocking ability increased at first and then decreased with the gas-liquid ratio increasing, When the ratio of gas-liquid was 1:1, the blocking ability reached the best effect. Moreover, as permeability improved, the blocking ability increased; while the increase of oil saturation, its blocking ability gradually decreased.Air foam flooding could enhance oil recovery by 8.06%, and decrease water cut of produced fluids, water cut decreased from 98.12% to 60.34% through the single tube experiment results. The founding of two-tube parallel displacing oil experiments shown that, in the stage of water flooding, the rate of oil producing was quite fast in the hypertonic tube, and the recovery reached 53.64%, while the recovery of hypotonic tube was 10.94%. In addition, the oil recovery of hypertonic tube increased from 53.64% to 62.27% in the air foam flooding stage; while hypotonic tube oil recovery increased from 10.94% to 20.31%; meanwhile, due to the blocking profile effect of foam, the total water cut decreased from 98.23% to 65.89%. After foam flooding, the reservoir took water flooding again by injecting water. It made oil production continued to increase, eventually the total recovery reaching 51.18%.更多还原