Oil field pressure simulation - aquifer interdiction simulation
Steam injection is used in the Kern River field
(California) to increase the temperature of the reservoir rock and lower the
oil viscosity to facilitate pumping/production. A strong aquifer acts on the
southwest corner of the field and is the source of cold water moving updip towards
the production sector of the reservoir, with the consequent cooling effect. One
of the goals of this simulation is to predict the efficiency of interdiction
wells in reducing the influx of aquifer water into the producing sector of the
field.
The average combined production of 4900
wells is approximately 700,000 BPD, and the average steam injection with 1250
wells is approx. 150,000 BWPD. Production and injection performance for each
well in the field is available on a monthly basis. A water interdiction
strategy consisting of 17 wells with a combined total production of 410,000 BPD
was proposed to reduce the influx of water into the producing area.
The Kern River field model contains 6196 wells.
Aquifer interdiction wells are shown with higher well markers. Using the
reservoir data and production history, the simulation study was meant to
forecast the efficiency of the interdiction wells and to provide insights for
future interdiction strategies.
Water table and pressure isosurfaces in a neighborhood of the interdiction wells. Isosurfaces of pressure around the interdiction wells and pressure on a cutting plane. Well defined water table cones around the interdiction wells show qualitatively the advantage of using ReSolution for saturated/unsaturated interfaces.
Conclusions
ReSolution produces accurate pressure distributions without mesh clustering around the wells, and without resorting to simplifying assumptions such as those necessary to safely apply wells productivity indexes. ReSolution's well model is a new discretisation technique that takes into account the relevant parameters that characterize the near-wellbore pressure distribution.
The Kern River (Texaco) aquifer interdiction simulation including more than 6000 wells is an example of the use of ReSolution's simulation technology. ReSolution's well model is very easy to use because the computational mesh does not have to represent the wells. Wells of any type (vertical, horizontal) can be added to the oil reservoir model just by defining the well's trajectory and pertinent information such as diameter, completion, production, etc. Comparisons with analytical results validated the accuracy of this technique.
In short, for the simulation of fluid
saturation interface applications, ReSolution is superior to classical
FD/FV/FEM based simulators, both in terms of solution accuracy and CPU time.
For the same accuracy, ReSolution requires between one and two orders of
magnitude less CPU time than classical FE/FV/FD techniques.