稠油油藏气体辅助蒸汽吞吐研究现状及发展方向

Research status and development direction of gas assisted cyclic steam stimulation in heavy oil reservoirs

稠油是一种解决能源危机的低品位石油资源,稠油开采属于世界性难题,蒸汽吞吐尤其适用于地质条件复杂的稠油油藏,但目前稠油油藏经高轮次蒸汽吞吐后存在油藏压力降低、储层动用不均匀、汽窜等问题,辅助气体有助于解决吞吐后期出现的此类问题,综述了现阶段氮气、CO_2、烟道气、泡沫等辅助蒸汽吞吐技术的辅助机理、优化注采、创新应用,并剖析了各种辅助方法的优缺点,提出氮气与CO_2联合辅助蒸汽吞吐,基于井下蒸汽发生器、井下降黏设备、氮气的有机结合是未来辅助蒸汽吞吐的发展方向,为后续技术储备及创新提供参考。

Heavy oil is a kind of low-grade oil resource that can solve energy crisis,but its production is a global difficulty.Cyclic steam stimulation is particularly suitable for heavy oil reservoirs which are geologically complex.After multicyclic steam stimulation,however,heavy oil reservoirs are suffered from a series of problems,e.g.reservoir pressure decrease,nonuniform reservoir production and steam channeling.And assistant gas is conducive to solve these problems which occur in the late stage of cyclic steam stimulation.In this paper,the assisting mechanisms,injection-production optimization and innovative application of current cyclic steam assisting technologies were reviewed,including nitrogen,CO2,flue gas and foam.Then,their advantages and disadvantages were analyzed.Finally,it was proposed to combine nitrogen with CO2 to assist cyclic steam stimulation,and it was pointed out that the organic combination of downhole steam generator,downhole viscosity reducing unit and nitrogen is the development direction of assisted cyclic steam stimulation in the future.The research results provide the reference for the subsequent technical reserves and innovation.