Research on Heavy Oil Dispersion and Drag Reduction Technology and Integrated Process

The heavy oil block in Dagang oilfield has high viscosity and poor flowability, which easily causes organic plugging in the wellbore during production, leading to difficulties in lifting and transportation. It is also easy cause pump blockage and self-shutdown, leading a short free period for maintenance for single well. Additionally, due to poor flowability, the crude oil in reservoir easily forms organic plugging in the near-wellbore area, affecting the production rate of single well, even shutdown of single well. Through crude oil property analysis, screening of viscosity reducers, and performance evaluation of formula systems for reservoir protection, a heavy oil dispersing and reducing technology has been developed. This technology can significantly reduce the viscosity of heavy oil, with a viscosity reduction rate of over 96% at 50 ℃ and a viscosity reduction rate of 94.9% at 20 ℃ under flowing conditions. The surface tension of the system is low, with an anti-swelling rate of over 90%, and a washing oil rate of over 90%. It also has good compatibility with formation water. Supporting technologies include viscosity-reducing injection, manual dosing, and online viscosity reduction processes. This technology has been applied to 44 wells using three injection methods, with a 100% effective rate, significantly reducing the viscosity of crude oil and achieving cold production and transportation of heavy oil, effectively extending the interval for individual well maintenance and ensuring safe and stable oil production.