刚果深水稠油井井筒电缆加热降黏工艺

WELLBORE ELECTRIC HEATING-VISBREAKING TECHNOLOGY FOR CONGO DEEPWATER HEAVY OILFIELD

针对中海油刚果（布）M深水稠油油藏油井产液因黏度远远高于倾点黏度而造成流动困难的问题,研究了螺杆泵空心杆电缆加热降黏工艺,建立了相应的井筒温度分布模型,可精确模拟井筒产液温度分布.分析了保温管、电缆加热功率及加热深度对井筒中地层产出液体温度分布的影响.结果表明：单独使用保温油管或加热电缆降黏效果有限,而将两者配合使用的复合降黏工艺降黏效果显著;提高复合加热降黏工艺的电缆加热功率或保温管级别,均可明显增强加热降黏效果;复合加热降黏工艺存在最佳加热深度,在此深度加热能够实现全井筒降黏效果最大化,降低能耗,节约成本.该区块是中国首次开发的深水稠油油田,电缆加热降黏工艺提供了有效技术手段.

In the light of the flow difficult resulted from the higher produced fluid viscosity than that of the pour point （PP} for the oil wells in Congo {The Republic of Congo} deepwater heavy oil reservoir M of CNOOC, the heating-visbreaking technology by the hollow rod cable of the progressive cavity pump well is developed and moreo- ver the corresponding wellbore temperature distribution models are established, thus the distributions of the pro- duced liquid can be precisely simulated. The influences of the insulating tube~ power of the electric heater and heated depth on the distributions are analyzed. The results show that the visbreaking effect is limited for the sole use the insulating tube or electric heating cable, but the complex visbreaking effect is prominent for the use of both of the above ; and moreover the complex visbreaking effect can be enhanced obviously when the heating power or the insulating tube level is increased; there exist an optimal heated depth for the complex heating technology j thus the optimized visbreaking effect in the whole wellbore can be realized at this depth, so the energy consumption can be decreased and the cost can be economized. This block is the first deepwater heavy-oil reservoir that explored by China, the heating-visbreaking technology by the cable has become one kind of effective developing methods.