海上油气田伴生气产量的修正及其意义

Production Correction of Associated Gas in Offshore Oil Field and Its Significance

海上油气田普遍使用油气计量分离器对油井的伴生气进行计量,但此方法往往忽略了溶解在原油中的伴生天然气,以至上游计量结果难以真实有效地反映实际伴生气产量,与下游终端接收的天然气产量存在较大的误差。而由于伴生气计量结果较实际偏低,将有可能出现混输海管和生产处理设备超设计情况而不自知,存在安全隐患。通过文献调研得到天然气溶解度在不同压力及温度下的关系式,用于计算在油气计量分离器运行工况下伴生天然气在原油中的溶解度,进而得到溶解在原油中伴生天然气体积,并通过计算结果对伴生天然气产量系数进行修正,从而更为准确地反映实际伴生气产量。

Offshore oil and gas fields generally use oil-gas metering separator to measure the associated gas of oil wells,but the natural gas production measured by this method often ignores the associated gas dissolved in crude oil. The upstream metering results are difficult to truly and effectively reflect the actual associated gas production,and there is a large error with the natural gas production received by the downstream terminal. In this case,the measurement result of associated gas is lower than the actual situation,and it is possible that the mixed transportation pipeline and production and treatment equipment exceed the design without knowing it,which has potential safety hazards. Through literature research,this paper obtains the relationship of natural gas solubility under different pressures and temperatures,calculates the solubility of associated natural gas in crude oil under the operating conditions of oil-gas metering separator,and then obtains the volume of associated natural gas dissolved in crude oil,and corrects the coefficient of associated natural gas production through the calculation results,so as to reflect the actual associated gas production more accurately.