Haute Mer A区块深水稠油油田降黏工艺研究

Technique for Viscosity Reduction of Deepwater Heavy Oil in Block Haute Mer A

中海油在刚果(布)的Haute Mer A区块深水稠油油藏水深达到1050m,海底泥线处温度6℃左右,原油在该环境下黏度可达到15260mPa·s,高于倾点黏度,流动困难,需采取降黏措施才能确保原油流过低温区。针对该区块地温特征以及探井完井测试要求,建立了井筒-地层传热模型,模拟出了原油在井筒中的温度剖面,结果显示在泥线上200m附近井筒温度最低。精确预测了电加热降黏以及化学降黏两种可行方案下的井筒内原油温度,并对这两种方案进行降黏效果优选,认为电加热降黏为该区块最佳降黏方案,化学降黏法不适合该类深水油田。该区块是中国首次尝试开发的深水稠油区块,为深水稠油油田井筒降黏工艺的优选提供了思路。

In Block Haute Mer A(CNOOC),deepwater heavy oil reservoirs in Congo were 1050mdeep,the temperature was about 6℃at mudline of seabed.Under this condition,viscosity of crude oil could be 15260mPa·s,which was higher than that of pour-point viscosity and it was hard for its flowing,thus it needed appropriate measures for viscosity reducing and ensuring crude oil flowing through a low temperature area.In allusion to the feature of in-situ temperature and well completion requirements of exploration wells,a model of wellbore-formation heat transfer was established for simulating the temperature profile of oil in the wellbore,the result indicated that the temperature was the lowest at 200 m above the mudline.The temperature of crude oil was predicted by using the feasible schemes of viscosity reduction using electric heating and chemical viscosity reduction,the effects of viscosity reduction of the 2schemes were chosen,it was considered that viscosity reduction using electric heating was optimal one in the area,the chemical viscosity reduction was not suitable for these types of oilfields.It is the first time for CNOOC to operate in deepwater and heavy-oil block,it provides idea for optimizing the technologies of wellbore viscosity reduction for oilfields with deepwater and heavy oil.