Industrial Technology & Science - Enhanced Oil Recovery
Oil recovery refers to the process by which crude oil is extracted from an oil reservoir below the Earth's surface, and can be categorised into three phases:
- The primary phase, where up to 10% of the available oil is pushed out due to the natural pressure difference between the reservoir and the surface;
- The secondary phase, where pressurised water and gas are injected into the reservoir, attaining an additional recovery of up to 30% of the oil available;
- The tertiary phase, also known as Enhanced Oil Recovery (EOR), where thermal processes and chemicals compounds, including emulsions with polymers and/or nanoparticles, can be used to achieve up to 60% recovery rates. Such molecular-scale additives must be specifically tailored to the real reservoir conditions in order to maximize the effectiveness of this costly operation.
A considerable amount of oil resides in micro- and nanoscale pores inside reservoir rocks. In those tiny pores, the fluid flow properties are mainly determined by the interaction between the fluids and the rock. A technique called "Digital Rock Analysis" uses X-ray microtomography or nanotomography of reservoir rock samples to study fluid flow in such systems. However, current analysis tools do not capture the fluid-rock interaction, focusing only on the geometry of the pores. The inclusion of these nanoscale interactions will greatly benefit the accuracy of a simulator, allowing it to be used as a testbed for EOR approaches.
Our approach enriches the geometrical representation of reservoir rocks with physical information on wettability, surface chemistry and physical parameters to predict the rock's fluid transport properties. Therefore it enables highly-efficient simulated screenings of EOR additives, leading to reduction of costs associated with field trials.
*Tomography data downloaded from http://www.rockphysics.ethz.ch.
At IBM Research - Brazil we are bringing Nanotechnology to the oilfield by developing a simulator able to take input from experimental characterization of fluids (oil, water, gas, ...) and solids (reservoir rocks, nanoparticles,...), from the nanoscale to the macroscale, in order to predict how efficient a given EOR additive is on improving the oil recovery rates.
MD = Molecular Dynamics
LBM = Lattice Boltzmann Method