某区块泡沫油形成原因及泡沫体积影响因素试验研究

Experimental Research on the Reasons of Foamy Oil Formation and the Bubble Volume Affected Factors in A Block

针对大庆油田某区块形成泡沫油与邻近未形成泡沫油的区块开展了原油族组成、原油碳族成、地层水矿化度和油气界面张力测定对比研究。通过泡沫油岩心流动试验研究了不同溶解气油比、含水率、岩心渗透率、驱替压差对泡沫油体积的影响规律。结果表明:形成泡沫油与邻近未形成泡沫油的区块相比饱和烃含量高、轻质碳同位素含量高、地层水矿化度低、油气界面张力低。通过岩心后泡沫油体积随着原油中溶解气油比增大、含水率减小而增大。该研究条件(1.23~15.98mD)下岩心渗透率越小泡沫油稳定存在的时间越长。驱替压差越大,泡沫油稳定存在时间越长,但影响程度较弱。该研究思路及成果对生产过程中出现泡沫油区块的原因分析及高效开发具有借鉴意义和工程指导价值。

A comparative study was carried out on detection of the composition of crude oil family,its carbon composition,the salinity of formation water and the interfacial tension of oil and gas in consideration of foamy oil formation in a block and in the block without foamy oil formation in Daqing Oilfield.By a core flow test on the foamy oil cores,the rule of effects of dissolved oil and gas ratio,water content,core permeability and displacement pressure on the volume of foamy oil was studied.The result indicated that compared with the block without forming the foamy oil in the nearby area,in the block with foamy oil,the saturated hydrocarbon content was high,the content of light hydrocarbon isotope was high,the salinity of formation water was low and the oil and gas interfacial tension was low.The bubble volume through core increased with the increase of dissolved gas-oil ratio and the reduction of water content.Under the condition of the research(1.23~15.98 mD),thesmaller the core permeability was,the longer the stabilization time of foamy oil was.The higher the displacement pressure difference was,the longer the stabilization time of foamy oil was,but the influence was weak.This research idea and results provide reference and engineering guidance for analyzing the causes of forming foamy oil and efficient development in the block.