Gas Injection Modelling and Simulation in the Tight Lower Cretaceous Reservoirs
Abstract
Gas injection is considered one of the only methods to enhance oil recovery from tight Lower Cretaceous reservoirs in the Danish sector of the Norths Sea. These reservoirs are characterized as tight (0.1 – 10 mD) and are not fractured. One productive example is the Valdemar field which is primarily produced through pressure depletion. Gas injection is being investigated with the aim to improve ultimate recovery from this field.
Gas injection works through a number of mechanisms. One is through the additional energy through the addition of gas, driving out the remaining oil. Since water injection is not viable for these fields this process alone is very important to the enhancement of recovery. A secondary important process is the mixing of the injected gas with the reservoir oil. Through multiple contacts it is possible for the recovery at the pore scale to reach 100%.
In this seminar a number of works carried out to understand how the oil will respond to gas injection will be presented along with a number of early simulations aiming to investigate how different injection scenarios and fluids may impact ultimate recovery.