气动力解堵技术在低渗透油田的应用

Application of Plug Removal Technology with High Pressure Gas in Low Permeability Oilfield

油田开发过程中,为保证油井正常生产,洗井和作业是常见的维护措施,在此过程中,不可避免的有部分入井液渗入近井地带,造成污染,导致油井产量下降,油田通常采取酸化措施来恢复油井产能。但当油井近井污染程度严重时,常规的酸化措施不能有效解除污染。为此,近几年发展了解堵能力和作用效果更为明显的气动力深穿透油层复合解堵技术。从理论和现场两方面论述了气动力解堵技术在低产、低渗透油田的应用。技术主要作用机理包括:机械作用、振动脉冲作用、放热作用和化学作用;现场共试验15口井,累计增油1161t。通过地面微地震监测表明,气动力解堵技术可以在油井近井地带产生多条径向裂缝;固井质量检测表明,该技术对固井质量有一定影响,但固井质量仍合格;井下油管有灼痕现象,但油管的力学性能及化学成分未发生变化,仍符合油管标准。

Well-flushing and operation are the conventional maintenance measures for normal production of the oil wells in the development process of the oilfield.Inevitably,some injected fluid will pollute immediate vicinity of wellbore,so the well production will drop.Acid treatment is a normal measure for recovering well production.But conventional acid treatment can′t effectively remove the serious pollution of the immediate vicinity of wellbore,so in recent years,the plug removal technology with high pressure gas has been introduced and developed that has the ability of obvious plug removal.The application of this technology in the oilfield with low oil production and low permeability is discussed from the theory and field application.Active mechanism include mechanical effect,vibration impulse effect,heat effect and chemical effect.The cumulative incremental production of 15 field test wells are 1161.0t.Micro seismic monitoring on surface shows that the plug removal technology with high pressure gas will creat several radial fractures at the immediate vicinity of wellbore of oil wells;cementing quality monitoring indicates that the plug removal technology with high pressure gas makes some effects on cementing quality,but the cementing quality is still qualified;oil tubes have some calcination,but they are still available for no change on its mechanical performance and chemical composition.