SAGD technology conceptual design of thermal recovery explore for offshore extra-heavy oil

Within the last decade, SAGD (steam-assisted gravity drainage) technology was one of the new efficient technologies for development of extra-heavy oil, however the application of this technology is even a greater challenge in complex offshore environment. Combined the SAGD technology development experiences at domestic and foreign with the actual situation of Bohai Luda extra-heavy oil reservoir, after analyzing steam injection process, production process and ground engineering of SAGD, it turns out that the SAGD development process in this reservoir should be: warm-up, step-down and SAGD operation. Optimizations have been done to the different stages of the steam injection and artificial lift technology: using concentric double tube uniform steam injection in the steam injection well, using gas lift in the step-down stage of the production well, and producing with high temperature electric pump in the SAGD operation stage. Use miniaturization, skid-mounted thermal recovery equipment on the ground with processes optimized. Overall, it was proved that the SAGD technology can be implemented in this oilfield, which provides the theoretical basis and technical support for conducting pilot test of SAGD in offshore oil fields.