油井油套环空产气规律

Analysis on tubing-casing annular gas production

油井机采优化设计时,气油比是一个重要参数。目前对气油比的计算仅以计量间里测量出来经泵生产的一部分气量为依据,而忽略了放套管气生产井的套管气产量,这给计算结果带来了较大的误差。针对放套管气生产油井,现场测试了多口油井的套管气量,比较了考虑套管气与忽略套管气对气油比计算结果的差异,证明忽略套管气产量会给气油比计算结果带来较大偏差。在管鞋处压力小于泡点压力时,套管气产量与套管与油管截面积之比及套管沉没压力值存在比例关系。建议在油井机采优化设计中,可采用计算或实测回归等方法估算出套管气量,并加入到气油比计算中。

Gas - oil rate is an important to optimize mechanical recovery. The currently used calculating method of gas - oil rate is only based on the partial gas measured in the metering room, which neglects the casing gas. As a result, bigger error is caused by the calculating results. In view of the production oil wells generating casing gas, the casing gas is measured in several wells, The difference between the calculating results of gas - oil rate considering or neglecting casing gas is compared. It is demonstrated that bigger error will be caused without considering casing gas. When the pressure at the casing shoe is lower than the bubble point pressure, there is a certain proportion relation between the casing gas production and the submergence pressure as well as the casing - tubing sectional area ratio. It is proposed that the casing gas be taken into account to determine the gas - oil rate during the optimization of mechanical recovery. The methods such as the calculating method and the practical measurement method can be applied to estimate the casing gas production and then add it into the calculation of gas - oil rate.