DISCUSSION ON THE METHOD FOR RECOVERING CASING GAS USING A CHECK VALVE

Casing gas can be recovered by installing a check valve between flow line and casing outlet of a oil well.After installation of a check valve in oil well,the average casing pressure may become larger than before.This paper analyses the effect of casing pressure variation on pump efficiency by an example with five submergence depths and three gas-oil ratios.Results show that it is reasonable and practical to use check valve to recover casing gas.The method for determining submergence depth and pump setting depth corresponding to maxmum pump efficiency is carried out in this paper.