潜山裂缝油藏降压开采增油机理及现场试验

系统地总结了任丘裂缝型碳酸盐岩潜山油藏在“九五”期间开展的降压开采现场试验成果.降压开采增油机理是通过驱动方式的改变,使油水关系重新分布,并利用裂缝的差异性闭合效应,使弹性力、重力和毛细管力的有利驱油作用得到了更好的发挥,减小了大裂缝的渗流能力及其对中小缝洞与岩块系统的干扰,从而发挥了中小缝洞及岩块系统的生产潜力.在此基础上提出了裂缝性油藏实施降压开采的时机与速度,对改善潜山油藏中、后期开发效果和提高采收率试验研究具有重要意义.

Mechanism of depressurization development of fractured reservoirs for enhancing oil production and in-situ experiment

The depressurization development is a special method for increasing oil recovery rate by using unstable water flooding.The field test results of depressurization development of fractured reservoirs in carbonate buried hill of Renqiu Oilfield carried out during the ninth five-year perion were systematically summarized.The depressurization development mechanism for enhancing oil production is to make the oil-water relationship redistributed as changing driving means and utilizing the differential closure effect of fissures to make the favorable oil displacement actions of elastic force,weight and capillary forces more effective and reduce the seepage flow rate of big fissures and the interference of seepage flow in small-middle fissures,pores and blocks of rocks,which brings the productive potentialities of small-middle fissures,pores and blocks of rocks into play.The opportunities for taking depressurization developing measures and suitable developing speeds for depressurization development were proposed.It is significant for improving developing effects and test research on enhancing recovery ratios in medium-term and late period.