Heavy oils are characterized by high-density, high-viscosity, and high-heavy-fraction components. One of the more common characteristics of heavy oil reservoirs is a low primary recovery factor, which is mainly because of unfavorable mobility ratios between oil and water, negligible solution drives, and faster decline of reservoir pressures because of relatively low oil compressibility. Most of the technologies that apply to heavy oil reservoirs need to address the mobility ratio or viscous forces before any flooding. Given the complex nature of heavy oil reservoirs, paper SPE 209328 present a comprehensive review of the latest technologies and work flows developed for heavy oil reservoir management.
Although secondary oil production methods such as waterflooding, water-alternating-gas injection, and gas drive might not be efficient in recovery from heavy oil reservoirs, the applicability and success of these methods can be analyzed on a reservoir basis.
The offtake and throughput management philosophy for heavy oil waterflooding is not the same as for classical light oil, and it could play a major role in recovery efficiency. The key point is to understand the nature of heavy oil and reservoir heterogeneity regarding their fluid and rock properties. Recent technology advances in hardware and software have enabled the industry with tools that allow achieving full-field high-resolution simulation modeling; therefore, performing a realistic reservoir simulation is achievable. This might decrease the loss of millions of dollars before field applications. Paper SPE 210185 presents an example of taking advantage of recent simulation technologies and presents a method and work flow under subsurface uncertainty for a large heavy oil field with complex geological characteristics, a long production history, and many wells. The work-flow design is applicable for other fields with similar characteristics and delivery objectives.
Paper SPE 203783 discusses the results of a recovery-optimization study conducted in a heavy oil field in south Oman aimed at improving the understanding of deep bottom-up water injection.
This Month’s Technical Papers
Automated Reservoir Model Calibration Applied to a Complex Multizone Heavy Oil Field
Study Reviews Technologies, Work Flows in Heavy Oil Reservoir Management
Study Details Strategy of Bottom-Up Water injection in a Heavy Oil Reservoir
Recommended Additional Reading
SPE 205449 First Successful Controlled Dumpflood in Deepwater Gulf of Mexico Results in Promising Incremental Rate and Recovery by Bilal A. Hakim, Talos Energy, et al.
URTeC 2021-5077 Heavy Oil Polymer Enhanced Oil Recovery in the Challenging Alaskan Arctic—It Works! by A. Dandekar, University of Alaska Fairbanks, et al.
SPE 212387 Evaluation of the Oil Recovery and Economic Benefit of the First-Ever Polymerflood Field Pilot To Enhance the Recovery of Heavy Oils on Alaska’s North Slope Using Machine-Assisted Reservoir Simulation by Cody Douglas Keith, University of Alaska Fairbanks
Mehdi Izadi, SPE, is a senior reservoir engineer with ExxonMobil Upstream in Houston. Currently, he is a member of a team responsible for asset development planning in deepwater gas condensate reservoirs in Guyana. Izadi holds PhD and MS degrees in petroleum engineering from the Colorado School of Mines. He has more than 20 years of experience in classical reservoir engineering analysis, reservoir simulation, and enhanced-oil-recovery (EOR) technologies. Izadi has been teaching industrial courses and providing onsite training on chemical EOR simulation and reservoir modeling for several years.