The Study Of Steam Drive After Steam Soaking In A-Oil Reservoir

A block belongs to shallow heavy oil reservoir, formation permeability is low, low reservoir pressure, conventional water flooding development is difficult, need through the indoor experiment, numerical simulation and reservoir engineering design methods, research suitable for A block of heavy oil thermal recovery feasibility, injection-production parameters and related supporting technology. Due to the high viscosity of crude oil, make this kind of reservoir development of a conventional injection water easy to dash, development process has the characteristics of early water cut rising fast, huge quantities of crude oil is often at the high water-cut stage, difficult to achieve economic and effective use, belongs to the difficult mining reserves. Therefore, it is necessary to carry out 81 blocks long steam drive feasibility study, explore the difficult economic and effective mining reserves producing technology.The author on the basis of literature review, the use of CMG numerical simulation software, the analysis of different well pattern well spacing in screening, results show that for A the thickness thin, net total thickness is larger than that of small reservoir, using vertical horizontal well combined well spacing can increase oil recovery. Using numerical simulation method to discusses the well pattern well spacing, vertical horizontal well spacing is 140 m. To the stage of steam stimulation and steam drive injection parameter optimization analysis, finally it is concluded that the optimal parameters for: the first cycle injection stage of steam stimulation vertical Wells is 1000m3, horizontal well is 4000m3. For multiple periodic stimulation operation, need to increase amount of steam injection line by cycle, by expanding the scope of the heating, generally recommend the addition of steam injection cycle is 10% ~ 15%. Stage of steam stimulation steam injection dryness is greater than 0.5.Optimizing the steam injection rate for vertical Wells more than 100m3/d, horizontal well 200m3/d. Soak time 5 days. As the result of the injection parameter optimization of steam drive stage: injection rate in the steam drive three stages are: heat connected phase of 100m3/d, 80m3/d steam flooding stage, stage of steam breakthrough 60m3/d. Production factor is greater than 1.2. Throughput after four rounds round of steam drive is the best time to displacement. Late in the steam flooding, steam breakthrough serious stage, transfer soda alternating flooding is an effective way of displacement to improve recovery effects.