基于OLGA的深水混输管道及井筒水合物风险分析

1. 中国石油大学(华东)石油工程学院;
2. 中国石油海洋工程有限公司海工事业部;
3. 中国石化胜利油田钻井工艺研究院

1. School of Petroleum Engineering, China University of Petroleum(Huadong);
2. Offshore Engineering Fabrication & Construction Division, CNPC Offshore Engineering Company Limited;
3. Drilling Technology Research Institute, SINOPEC Shengli Oilfield Company

为研究深水油气混输管道的水合物形成问题,结合西非安哥拉海域某油田开发数据,使用OLGA 软件对海底长输管道、立管和井筒内的水合物生成情况进行了数值模拟。结果表明:在所给出的油流组分和产量变化情况及设定的节点温度压力条件下,该管道与井筒的温度和压力范围不落在水合物生成区内,水合物生成风险极低;随着含水率升高,该油田海管管内压力、温度及管段总压降均升高,而管段温降减小;随着气油比增大,海管管内压力、温度及管段压降均降低,而管段温降增大。结合油流组分和工况,分析认为油藏产出水中含盐量很大,从而抑制了水合物的生成。

To study formation of hydrates during deepwater oil/gas flow assurance, development data of an offshore oilfield in Angola, West Africa, are used with OLGA software to numerically simulate formation of hydrates in subsea flowline, riser and borehole. The results show that, under specific oil compositions, productivity variations and pre-determined node temperatures/pressures, the temperatures and pressures in the pipelines and boreholes are outside of the extent for formation of hydrates, implying extremely low risks related to formation of hydrates. With the increase of watercut, both internal pressure and overall pressure drop of pipeline increase, and internal temperature increases, while overall temperature drop decreases. With the increase of gas/oil ratio, internal pressure and overall pressure drop both decrease, and internal temperature decreases, while overall temperature increases. The analysis from the oil flow composition and working conditions shows high salinity in produced water of the reservoir, which inhibit formation of hydrates.