Study On Foam Flooding Technology In Bozhong 34-1 Oilfield

Offshore oil and gas field development havs always been continuously significant in domestic petroleum industry.In this paper, BoZhong 34-1 oilfield was selected as a representative offshore oilfield to complete the evaluation and optimization of foam combination technology adopted in offshore oilfields for further increasing oil recovery after water flooding.According to the characteristics of BoZhong 34-1 oilfield and the purpose of profile control and flooding, the surfactant foaming ability, foam stability and foam efficiency of foaming agent were selected as main parameters for evaluating. Pointing out that the surfactant BM under concentration of 0.8% has better performance in initial volume of foam,foam drain stability and concentration optimization than other common surfactant applicated in offshore oilfields through the method of Waring Blender. Based on this completion, complex surfactant system shows better performance in initial volume of foam and foam drain stability in the study of mixture surfactant system. Experiments also determine that the mixture surfactant system of 0.3%LAO plus 0.5%ABS exactly under concentration of 0.8% has the best initial volume of foam and foam drain stability within the geology condition of BoZhong 34-1 oilfield. In addition,experimental conclusions also show that complex foam system modulated with varied concentration polymer and surfactants have the abilities in reducing initial foaming volume and enhancing foam stability. The surfactant mixture was developed as foaming agent, and the performance of the mixture is more advanced than that of the mono-constituent in foaming and stability. Based on the investigation of the interaction between polymer and surfactants, the composition of polymer and foam combination system was determined by the foam stability and foam generation ability. Ultimately, research carried out to study the influences of the method and occasion of foam input in offshore oilfield plugging flood stage, the conclusion reveals that inputting foam surfactant and gas alternately has better performance than surfactant-gas plug, and also, inputting foam system under high residual oil saturation in advance than normal,In this paper, experiments provide the offshore oilfield foam system with characterization of the surfactant foaming ability and foam stability. Basing on these experimental conclusions, it supplies optimization and evaluation for selecting foam surfactant in accordance with the real condition of BoZhong 34-1 oilfield. Supported by artificial core physical model it offers experimental conclusions that explains how the plugging ability get affected by the method and occasion of offshore oilfield foam input. These experimental conclusions also provide reference and experimental foundation for optimization and evaluation, also the method and occasion of foam input, of foam system using for reservoir plugging in other offshore oilfields.