Numerical simulation and optimisation of IOR and EOR processes in high-resolution models for fractured carbonate reservoirs
Abstract
Carbonate reservoirs contain more than half of the world’s conventional hydrocarbon
resources. Hydrocarbon recovery in carbonates, however, is typically low,
due to multi-scale geological heterogeneities that are a result of complex diagenetic,
reactive, depositional and deformational processes. Improved Oil Recovery
(IOR) and Enhanced Oil Recovery (EOR) methods are increasingly considered
to maximise oil recovery and minimise field development costs. This is particularly
important for carbonate reservoirs containing fractures networks, which
can act as high permeability fluid flow pathways or impermeable barriers during
interaction with the complex host rock matrix.
In this thesis, three important contributions relating to EOR simulation and
optimisation in fractured carbonate reservoirs are made using a high-resolution
analogue reservoir model for the Arab D formation. First, a systematic approach
is employed to investigate, analyse and increase understanding of the fundamental
controls on fluid flow in heterogeneous carbonate systems using numerical
well testing, secondary and tertiary recovery simulations. Secondly, the interplay
between wettability, hysteresis and fracture-matrix exchange during combined
CO2 EOR and sequestration is examined. Finally, data-driven surrogates, which
construct an approximation of time-consuming numerical simulations, are used
for rapid simulation and optimisation of EOR processes in fractured carbonate
reservoirs while considering multiple geological uncertainty scenarios.