目前,全国绝大多数油田都采用注水开发,并且很多油井都先后进入中、高含水期。为了保证高含水量的原油产量,必须加大采液量。在有杆泵抽油井中,提高采液量的有效方法就是用大泵抽油,大泵抽油的特点是具有较大的抽汲速度。但是,理论分析和生产实践证明,在用大泵和大抽汲速度的工况下,下冲程时,柱塞要受到较大的阻力,因而抽油杆柱的 At present, the vast majority of oilfields all adopt waterflooding development, and many oil wells have successively entered the medium and high water cut-off periods. In order to ensure high water content of crude oil production, must increase the amount of fluid collection. In sucker rod pumping wells, an effective way to increase the amount of liquid production is to use a large pump to pump oil, which is characterized by a large pumping speed. However, theoretical analysis and production practice have proved that the plunger suffers greater resistance under the conditions of large pump and large pumping speed, and the lower resistance of the sucker rod