Abstract
As a new potential mean of artificial lift production, production using progressive cavity pump (PCP) has many advantages such as energy saving, lower first investment, and convenient in management. However, it is more challenging to implement this lifting method to thermal production of heavy oil for the temperature limitation of elastomer stator and bonding agent, and hostile temperature vibration in the wellbore environment, as a result, up to date, there is no application of PCP to thermal heavy oil production in Liaohe Oilfield which is the largest heavy oil field in China.
An applicable thermal PCP developed based on extensive testing is introduced in this paper. It involves an applicable thermal fluororubber stator and bonding agent which could operate under high temperature conditions (up to 210°C) enough for the thermal requirement of steam injection, and great temperature vibration condition in the wellbore ranging from 80°C to 210°C. The whole top-drive thermal pumping unit is designed in consideration of thermal wellbore environment in heavy oil production procedure of steam stimulation.
The thermal PCPs have been applied to 5 wells and detailed field testing dynamic is monitored and investigated. Favorable performance of the thermal pumping unit is observed in the rugged production environment (the measured wellbore fluid temperature is up to 165°C) for more than 6 months, and the pump efficiency is about 60%~70%. Compared with the conventional rod pumping lift production, about 20% increase in periodical cumulative oil production and 50% lower horsepower requirements is obtained.
In summary, the developed thermal progressive cavity pump is feasible for heavy oil production in steam stimulation process, which could operate under extensive temperature range, and the upper limitation is up to 210°C.
