Improved and enhanced oil recovery evaluate how reservoir management, well interventions, injection strategies and advanced displacement mechanisms can increase ultimate recovery.
Recovery engineering
As a field matures, the remaining hydrocarbons may become increasingly difficult to produce. Pressure depletion, reservoir heterogeneity, poor sweep, water or gas movement and well limitations can all reduce recovery efficiency.
IOR and EOR evaluation therefore begins with diagnosis. The appropriate recovery strategy depends on reservoir properties, fluid behaviour, existing wells, operating conditions, technical uncertainty and economic justification.
Recovery workflow
Recovery strategies should progress from evidence and diagnosis through technical screening, modelling and appropriately controlled implementation.
Establish why additional recovery is required and identify the reservoir and production mechanisms limiting current recovery.
Key activities
Evaluate whether the reservoir rock, fluids and existing well infrastructure are technically compatible with an improved or enhanced recovery strategy.
Key activities
Identify opportunities to improve recovery using reservoir management, well optimisation and other interventions before more complex recovery processes are considered.
Key activities
Screen enhanced recovery mechanisms against the reservoir, fluid system, operating environment and economic constraints.
Key activities
Use reservoir modelling and appropriately designed pilots to evaluate the expected technical response before wider field implementation.
Key activities
Implement the selected recovery strategy with defined performance measures and continuous surveillance of the reservoir response.
Key activities
Recovery methods
No recovery mechanism should be selected simply because it is technically available. Screening must establish compatibility with the reservoir, fluids, wells, facilities and operating environment.
IOR
Focuses on improving recovery through better reservoir management, well placement, production optimisation, injection management, workovers and other interventions using the existing reservoir and production system.
Typical focus
Better sweep, better well performance, better pressure support and better use of existing infrastructure.
EOR
Introduces additional displacement or recovery mechanisms beyond conventional primary and secondary recovery, selected according to reservoir and fluid characteristics.
Typical focus
Mobilising remaining hydrocarbons, improving displacement efficiency and increasing ultimate recovery where technically and economically justified.
Recovery decision
How much recoverable hydrocarbon remains and where is it located?
What reservoir mechanism is limiting current recovery?
Can improved reservoir management or well intervention increase recovery?
Is the reservoir technically suitable for an EOR process?
What evidence supports the selected recovery mechanism?
What pilot, modelling or surveillance programme is required before field-wide implementation?
Engineering chain
The engineering lifecycle
IOR and EOR do not represent the end of engineering. Recovery projects generate new production, pressure and reservoir data, which feeds back into surveillance, modelling and reservoir management.
Engineering lifecycle
Exploration, appraisal, reservoir characterisation, development, drilling, completion, testing, production, surveillance and recovery are connected through continuous engineering feedback.