Near-well simulations and modelling of oil production from reservoir
Abstract
One of the major challenges that the oil industry faces today is water breakthrough and high production of water from mature oil fields. Early water breakthrough can occur due to high frictional pressure drop in the well or due to fractures in the reservoirs.
Conventional inflow control devices (ICDs) are designed to delay water breakthrough but do not have the capability to control the water inflow after breakthrough. Autonomous inflow control devices (AICDs) are developed to choke the inflow of water after breakthrough has occurred.
An integrated transient wellbore-reservoir model is developed in OLGA-Rocx and simulations are carried out with different types of inflow controllers. The functionality of the inflow controllers is studied for light oil reservoir and the results are compared. Additional simulations are carried out with heavy oil. Simulations are performed for different permeability profiles in the reservoir. The study includes fractured reservoir, heterogeneous reservoir and the homogeneous reservoir. The results show that autonomous inflow controllers have a higher potential to limit the water influx compared to the conventional ICDs.
In the homogeneous reservoir, the frictional pressure drop along the well was rather low causing similar production throughout the wellbore. Hence, the benefit of using AICDs was less significant than in the heterogeneous reservoir.
An equivalent AICD was chosen to represent eight normal AICDs to make the simulation more efficient in terms of both time and computational resources. Additional simulations were performed by using normal sized AICDs, and the results show that the accumulated oil was highly increased compared to the results obtained using the equivalent AICDs.