Abstract: A method may include determining, during a first time step within an iterative simulation process, various pseudo-pressure values based on model data. The method may include determining, during the first time step, a first set of skin factor values for the wellbore radial grid portions using the pseudo-pressure values. The method may include simulating, during the first time step, a first well production rate for a well within a reservoir region of interest using the first set of skin factor values and a first pressure distribution for the reservoir region of interest. The method may include simulating, during a second time step within the iterative simulation process, a second well production rate for the well using a second set of skin factor values and a second pressure distribution for the reservoir region of interest.

Abstract: A system and method of simulating fluid flow in a hydrocarbon reservoir is disclosed. The method includes obtaining a coarse grid model of the hydrocarbon reservoir and a trajectory of a wellbore that penetrates the hydrocarbon reservoir, and determining an initial grid geometry surrounding the trajectory. The method further includes constructing a reservoir simulation grid, conformal to the initial grid geometry in a first region in a vicinity of the wellbore and conformal with the coarse grid model in a second region more distant from the wellbore than the first region, and performing a hydrocarbon reservoir simulation, modeling a flow of fluid in the hydrocarbon reservoir based, at least in part, on the reservoir simulation grid.

Abstract: Performance of computers is improved during determination of pressure distribution among grid cells of a reservoir model during reservoir simulation by computer processing. Convergence can prove difficult to obtain when conditions cause a coefficient matrix involved in the processing to become indefinite. An indefinite coefficient matrix can occur either due to physical conditions in the reservoir related to vapor liquid equilibria, or due to nonphysical conditions created numerically due to improper derivatives. The conventional previously taken corrective action of time step cutting is avoided when convergence becomes difficult during reservoir simulation. Time step cutting has proven to be very costly, in terms of computer usage and time, for very large reservoirs having models involving millions, billions or more number of unknown parameter values.

Abstract: A method for reservoir simulation is disclosed. The method includes selecting a coarse grid size for a plurality of grid blocks in a reservoir model of a reservoir, computing, by a computer processor and based at least on a fractional flow curve of oil and water, a water saturation at a water front within a grid block of the plurality of grid blocks and an average water saturation of the grid block, and computing, by the computer processor and based at least on the water saturation at the water front within the grid block and the average water saturation of the grid block, a water saturation distribution in the reservoir by solving reservoir simulator equations, wherein solving the reservoir simulator equations comprises computing a single water saturation value for each of the plurality of grid blocks based on the coarse grid size.

Abstract: A method may include determining, during a first time step within an iterative simulation process, various pseudo-pressure values based on model data. The method may include determining, during the first time step, a first set of skin factor values for the wellbore radial grid portions using the pseudo-pressure values. The method may include simulating, during the first time step, a first well production rate for a well within a reservoir region of interest using the first set of skin factor values and a first pressure distribution for the reservoir region of interest. The method may include simulating, during a second time step within the iterative simulation process, a second well production rate for the well using a second set of skin factor values and a second pressure distribution for the reservoir region of interest.

Abstract: A data processing system is provided which determines the migration of oil and gas by a basin simulation section and predicts future reservoir performance from current reservoir production measures. The data processing system provides more accurate reservoir rock and fluid property distribution in reservoir locations between well locations where such attributes cannot be measured. The data processing system operates based on physical realities captured from migration by the basin simulation section. The data processing system differs from conventional methods, which use measurements obtained at the wells and interpolate between for regions between the wells using statistical techniques. Results from the data processing system shed more light into reservoir discontinuities among the wells, and yield better distribution of hydrogen sulfide, tar zones (Heavy Oil) within the reservoir.

Abstract: Computer system performance is improved during reservoir simulation runs where heterogeneous rock formations suffer from convergence problems. Convergence problems are affected by accurate determination of pressure distribution for reservoir simulation, which is very complex when properties or attributes of reservoir rock formations are heterogeneous. In heterogeneous reservoir rock formations, pressure distribution is affected over three dimensions by variations of rock permeability and porosity. The difficulty in convergence of the simulation runs results in increased computer operation and processing time and consequent computer usage costs. Improved determination of pressure distribution in heterogeneous rock formations permits acceptable initial pressure measures for pressure determination during reservoir simulation and to reduce convergence problems with existing reservoir simulation.

Abstract: Performance of computers is improved during determination of pressure distribution among grid cells of a reservoir model during reservoir simulation by computer processing. Convergence can prove difficult to obtain when conditions cause a coefficient matrix involved in the processing to become indefinite. An indefinite coefficient matrix can occur either due to physical conditions in the reservoir related to vapor liquid equilibria, or due to nonphysical conditions created numerically due to improper derivatives. The conventional previously taken corrective action of time step cutting is avoided when convergence becomes difficult during reservoir simulation. Time step cutting has proven to be very costly, in terms of computer usage and time, for very large reservoirs having models involving millions, billions or more number of unknown parameter values.

Abstract: Computer system performance is improved during reservoir simulation runs where heterogeneous rock formations suffer from convergence problems. Convergence problems are affected by accurate determination of pressure distribution for reservoir simulation, which is very complex when properties or attributes of reservoir rock formations are heterogeneous. In heterogeneous reservoir rock formations, pressure distribution is affected over three dimensions by variations of rock permeability and porosity. The difficulty in convergence of the simulation runs results in increased computer operation and processing time and consequent computer usage costs. Improved determination of pressure distribution in heterogeneous rock formations permits acceptable initial pressure measures for pressure determination during reservoir simulation and to reduce convergence problems with existing reservoir simulation.

Abstract: A data processing system is provided which determines the migration of oil and gas by a basin simulation section and predicts future reservoir performance from current reservoir production measures. The data processing system provides more accurate reservoir rock and fluid property distribution in reservoir locations between well locations where such attributes cannot be measured. The data processing system operates based on physical realities captured from migration by the basin simulation section. The data processing system differs from conventional methods, which use measurements obtained at the wells and interpolate between for regions between the wells using statistical techniques. Results from the data processing system shed more light into reservoir discontinuities among the wells, and yield better distribution of hydrogen sulfide, tar zones (Heavy Oil) within the reservoir.

Abstract: A convergent solution is provided for a coupled system where oil flow from a subsurface reservoir formation enters a number of pipes of a multi-branch well in the formation. An iterative linear system solver computer implemented methodology is developed, capable of handling a large number of unknowns which are present when modeling a multi-branch well. A systematic approach which defines proper boundary conditions at the reservoir level and at the wellhead is provided and utilized.

Abstract: Systems, computer implemented methods, and program products to determine approximate static well pressures for one or more arbitrary shaped wells by estimating the drainage volume of the one or more wells, are provided. The drainage volume of the one or more wells, for example, can be estimated from the one or more computed fluid flow flux vectors, and the approximate static well pressures for the one or more wells can be subsequently calculated by taking the pore volume average of the dynamic grid block pressures within the drainage volume of the one or more wells. The one or more fluid flow flux vectors can be calculated at each iteration in a numerical reservoir simulator as a part of standard simulator computations, negating a need for additional, extraneous computations to calculate effective drainage volume of the one or more wells.

Abstract: Three dimensional well block radius determiner machines, systems, program products, and computer implemented methods are provided to determine a three dimensional equivalent well block radius of a perforated grid block cell, with three dimensional flow, of a three dimensional coordinate grid block constructed over a three dimensional simulated well formation in a finite difference petroleum reservoir simulator. Various embodiments of the invention, for example, can beneficially account for both horizontal and vertical flow of oil through a well perforation without the need for complicated, expensive, and time-consuming numerical or iterative solutions. Embodiments of the present invention, for example, can be used as a part of legacy simulators thereby providing more accurate well block radius calculations, by accounting for both horizontal and vertical perforation flow, without introducing significant implementation hurdles, development costs, or simulation runtime delays.

Abstract: Systems, computer implemented methods, and program products to determine approximate static well pressures for one or more arbitrary shaped wells by estimating the drainage volume of the one or more wells, are provided. The drainage volume of the one or more wells, for example, can be estimated from the one or more computed fluid flow flux vectors, and the approximate static well pressures for the one or more wells can be subsequently calculated by taking the pore volume average of the dynamic grid block pressures within the drainage volume of the one or more wells. The one or more fluid flow flux vectors can be calculated at each iteration in a numerical reservoir simulator as a part of standard simulator computations, negating a need for additional, extraneous computations to calculate effective drainage volume of the one or more wells.

Abstract: Three dimensional well block radius determiner machines, systems, program products, and computer implemented methods are provided to determine a three dimensional equivalent well block radius of a perforated grid block cell, with three dimensional flow, of a three dimensional coordinate grid block constructed over a three dimensional simulated well formation in a finite difference petroleum reservoir simulator. Various embodiments of the invention, for example, can beneficially account for both horizontal and vertical flow of oil through a well perforation without the need for complicated, expensive, and time-consuming numerical or iterative solutions. Embodiments of the present invention, for example, can be used as a part of legacy simulators thereby providing more accurate well block radius calculations, by accounting for both horizontal and vertical perforation flow, without introducing significant implementation hurdles, development costs, or simulation runtime delays.