Heavy oil reservoirs generally suffer from low recovery factors and high operating cost. To optimize recovery and minimize operating cost, experience and insights should be collected to enable shift changes in development costs. Different options for enabling these developments are proven or suggested in this paper. Horizontal or deviated wells are considered the base case.
Heavy oil reservoirs often suffer from:
Unconsolidation and sand production due to immature rock
emulsions and annular solids transport causing plugging of screens and sand control failures
serious water or steam breakthrough due to mobility ratios preferentially producing unintended fluids
marginal production rates due to high viscosity and low reservoir pressure.
In addition, steam floods are challenged by high completion costs due to extreme temperatures encountered, and high energy consumption due to production of high temperature fluids.
All of these factors contribute to reduced ultimate recovery and well life.
The paper describes case studies and concepts for the optimization of such heavy oil production systems, including uncemented completions which are very often beneficial to minimize well cost, minimize sand control challenges and maximize recovery.