Fluid Mobility
- Production rate is proportional to fluid mobility, the measure of the efficiency of fluid movement through a reservoir
- Mobility of each fluid depends on its relative permeability, which changes significantly with fluid phase saturations in transition zones.
- Oil mobility at native reservoir and steam temperatures varies both vertically and laterally.
- Oil viscosity variations often dominate HOOS oil phase mobility, which generally decreases dramatically towards the base of pay.
- Water mobility often increases as water saturation increases towards base of pay or within top or middle water zones.
- Intersecting viscous fluid domains and sedimentologically controlled permeability domains in reservoirs produce complex mobility distributions in which recovery processes must operate, and
- Understanding and predicting oil and water mobility in HOOS reservoirs is the key to optimizing oil recovery processes.
Heavy Oil Recovery & Geotailoring
Geotailoring provides clients not only with appropriate knowledge regarding the best recovery process to suit their needs but how to best place wells and operate the chosen process. The following information outlines the characteristics of an ideal recovery process.
- An ideal recovery process is tolerant of unpredictable geological heterogeneity, or geotolerant.
- An ideal recovery process is energy efficient, and
- An ideal recovery process has minimal environmental impact (i.e., low water usage and low emission of CO2 and other gases).
Currently, there is no magic-bullet for heavy oil recovery. Different methods provide different benefits to recovery operations.
- Example 1: Mining of bitumen is very geotolerant, as barriers do not hinder recovery, but mining has very poor energy efficiency and very high emissions and water usage.
- Example 2: SAGD thermal recovery has lower emissions but regularly fails or underperforms in vertically compartmentalized reservoirs with shale barriers.
Informed decisions making must occur when deciding which recovery method and operating strategy will best fit specific HOOS recovery efforts. With this in mind, the importance of having professional geotailoring consultation becomes obvious.
