In order to support the development efficiency of fields with heavy and highly viscous oil, it is necessary to reduce the cost of its production both by optimizing operating expenses and capital investments, and by introducing new technologies or improvements of existing technologies that enhance the oil recovery.
Steam-assisted gravity drainage (SAGD) is an industrially developed approach for producing heavy and highly viscous oil in reservoirs with a thickness of 10 to 50 m. This article considers two new schemes of SAGD applicable to the conditions of thick heavy and highly viscous oil reservoirs with a thickness of 100 m and more. The first proposed SAGD option involves drilling horizontal and downward deviated wells in the same vertical plane towards each other from different well pads. According to the sector hydrodynamic modeling results, this scheme allows to involve the additional volume of the reservoirs into the thermal stimulation and increase their oil recovery. The second considered SAGD option assumes drilling in a thick heavy and highly viscous oil reservoirs horizontal injectors and upward deviated producers located perpendicular to each other and alternating with the rows of vertical producers. It provides an increase in the estimated oil recovery due to the activation of heat and filtration flows in both vertical and lateral directions. Both schemes of SAGD allow reducing the number of wells for drilling and consequently the cost of the thick heavy and highly viscous oil reservoir development process.
1. Taraskin E.N., Zakharyan A.Z., Ursegov S.O., Adaptive option of steam injection technological efficiency evaluation for carbonate high-viscosity oil reservoir conditions (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 11, pp. 102–107.
2. Doan Q.T., Farouq Ali S.M., Tan T.B., SAGD performance variability – Analysis of actual production data for 28 Athabasca oil sands well pairs, SPE-195348-MS, 2019.
3. Loparev D.S., Chertenkov M.V., Buslaev G.V. et al., Improvement of drilling technology for the Yarega heavy oil field development by SAGD method with counter producing and injecting wells, SPE-171275-MS, 2014.
4. Konoplev Yu.P., Gerasimov I.V., 80 years of oil production on the Yaregskoye field of high-viscosity oil (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 7, pp. 30–32.
5. Taraskin E.N., Ursegov S.O., Improving SAGD efficiency in carbonate reservoirs by combining horizontal, deviated and vertical wells (In Russ.), SPE-187692-RU, 2017.
6. Patent no. RU2334096C1, Method of massive type high-viscosity oil pool development, Inventor: Khisamov R.S.
7. Patent no. RU2580339C1, Method for development massive type high-viscous oil deposit, Inventors: Ursegov S.O., Taraskin E.N.