Heavy Oil Recovery Using a Closed Loop Wellbore Heating System
Physical Sciences : Petroleum
Available for licensing
- Larry Lake, Ph.D. , Petroleum and Geosystems Engineering
- Babafemi Ogunyomi , Petroleum Geosystems Engineering
World conventional oil supplies consist of light oil that is declining in availability due to increasing demand. Other sources aside from light oil reservoirs must eventually be exploited in order to satisfy growing demands. Heavy oil is a possible solution to the impending problem of light oil deficiency. In fact, heavy oil comprises a greater fraction of hydrocarbons in sedimentary basins than conventional oil. The use of heavy oil on a global scale can potentially reduce oil prices and eliminate expenses for exploration of new conventional oil production methods.
Traditional methods for heavy oil production are based on the application of heat in order to reduce reservoir fluid viscosity, but have failed to function efficiently with high-viscosity heavy oil reservoirs. Modern non-thermal techniques, including chemical and biological injections, have been implemented but produce a small yield and allow sand from the sedimentary basin to enter the wellbore during production. With the growing depletion of conventional oil, it is imperative to establish an efficient and profitable method for heavy oil extraction.
The proposed heavy oil recovery method utilizes a very hot fluid flowing through a closed, U-shaped wellbore to heat the reservoir fluids. The resulting effect is lowered reservoir fluid viscosity and improved flow from the reservoir to a producing well. The invented closed-loop heating design, arrangement of wells, and application to heavy oil reservoirs are unique from previous heavy oil extraction methods. This method applies greatly to steam-assisted gravity drainage (SAGD) reservoirs, in which steam loss adds to operating expenses. In contrast, implementation of this method eliminates steam loss to the reservoir formation.
- Significantly lowers heavy-oil fluid viscosity
- Improved flow efficiency from reservoir to producing well
- Reduces operating expenses due to steam retention and elimination of chemical/biological treatment agents
- Thermal stimulation of reservoir fluid
- Closed-loop U-shaped wellbore heating system
- Unique arrangement of production wells
- Elimination of steam loss in SAGD reservoirs
Oil companies seeking to expand their horizons to include heavy oil as a major component of well production can implement the proposed wellbore heating system to improve productivity and reduce operating costs. The provision of heavy oil on a global basis can ease the growing demand for conventional oil, which is being depleted at an alarming rate. Heavy oil can be found in great quantities in accessible reservoirs, and can be made commercially available to the world by utilizing methods to improve reservoir flow.
- 1 PCT patent application filed