Integrated surveillance and modeling to monitor risk of fault re-activation during steam injection

In thermal EOR operations a major area of concern is the ability to maintain caprock integrity in order to operate the field safely and responsibly. A small area of large carbonate field in North Oman was used as a pilot to monitor steam injection to accelerate the gas-oil gravity drainage (see Figure 1 or [Saluja et al., 2010] for an overview). The reservoir of interest is a shallow fractured carbonate, which is located at the top of a series of reservoir layers, and is overlain by shale of around 250 m thickness. Simulation models are required to translate indirect observations or extrapolate point measurements of wells to give us a three dimensional view on field response to our production activities. This paper demonstrates the importance of having micro-seismic data as a source of surveillance data to constrain the geomechanical and thermal-flow simulations.