Reservoir Simulator

Reservoir simulator RN-KIM is designed to create, simulate and analyze three-dimensional digital oil and gas field models.

Description

In December 2021 it was 17 years since the first state registration of the RN-KIM computer program. The RN-KIM hydrodynamic simulator is designed to create and analyze three-dimensional digital field models. A digital field model is used to calculate reserves and forecast hydrocarbon production. The model takes into account the geological and field information about the field, reproduces the operation of the wells and is a digital clone of the field for the “what if” analysis.

Today, hydrodynamic modeling is characterized by complexity and increasing dimensions of models; multivariate parallel calculations on supercomputers are used all over the world. RN-KIM offers advanced computing technologies and daily use tools to support the development of large and giant reservoirs.

More than 1000 full-scale and sector models are prepared and updated annually in RN-KIM to solve wide range tasks.

What's new

We release updates of RN-KIM every three months.

Version 2022.6

Version 2022.6

We added:

  • the ability to create a profile along the trajectories of selected wells in "Trajectory" module;
  • an option to run models on the cluster using the interface;
  • the ability to set a layer number for local LGR refinement in ARITHMETIC section;
  • ExportCalcToRSM command to import RSM file next to the model for STARTUP file;
  • the ability to calculate bottomhole pressures to reference depth when importing.
Version 2022.4

Version 2022.4

We added:

  • injecting additions with the properties dependent on their time in the reservoir;
  • reservoir desalination;
  • modeling non-rectangular hydraulic fractures and setting petrophysical properties of the near-wellbore zone using automatic local grid refinement;
  • Baker's three-phase relative permeability models for compositional modeling;
  • group production, accounting for well bringing in/out production priorities depending on their rate ratios by phases;
  • automatic selection of non-drainage zones using maps of net oil pay zone and streamlines.
Version 2022.1

Version 2022.1

We added:

  • setting nested local refinements;
  • restarts using the date slide bar;
  • an option of cutting and stitching models with FLUX-regions;
  • viewing online graphs of simulation results;
  • a new 3D module;
  • report on adaptation;
  • improved project wells import window.
Version 2021.9

Version 2021.9

We added:

  • other logic of END keyword to stop the simulation;
  • the ability to set default values for RAD, MULT, SKIN parameters of PERF/SQUE events in EFIL(E) for the schedule section specified in a table format;
  • restriction in default setting of "Volume flow rate exponent" and "Viscosity function exponent" parameters in WSEGAICD keyword (parameters 13 and 14).

Besides:

  • Python-scripts can be used again for multi-threaded build on clusters;
  • Python is updated to version 3.8.
Version 2021.6

Version 2021.6

We added:

  • Running the simulation in various simulator versions.
  • User cubes export into *_ARR.INC file connecting this file with data-file.
  • Automatic actions with conditions on ACTIONC perforation.
  • Voidage replacement graphs.
  • Commenting in keywords COMPDAT, COMPDEV, COMPDATMD, FRACTURE, FRACTUREDEV, WFRACP.
Version 2021.3

Version 2021.3

We added:

  • Tables with indicators, diagrams, calculation progress bar into the console window.
  • Kriging interpolation function.
  • Export of wells tabular format (ETAB).
  • Storing and displaying the hierarchy of sidetracks into the «Scheme» module.
  • The parameters «Average permeability in the gas-oil zone» and «Average permeability in the oil zone» into Statistics.
Version 2020.12

Version 2020.12

We added:

  • User vectors (UDQ).
  • Surfactant injection modeling.
  • Miscible displacement.
  • Well segmentation module.
  • Creating regions for calculating current well reserves (FIPWELLS).
  • Creating Voronoi regions for the current date.
Version 2020.10

Version 2020.10

We added:

  • Compositional modeling.
  • Support for models with a tabular schedule file.
  • Date range input fields during a sector model creation.
  • Filters for locally modified grid.
  • Visualization of embedded LGR for the IJ profile.
Version 2020.6

Version 2020.6

We added:

  • The ability to start initialization without starting the full model simulation.
  • Setting the option of local grid refinement / coarsening in the 3D module.
  • Damping function support in the key words FRACTURE, FRACTUREDEV, FRACTUREL.
  • Displaying of the time and date of the simulation beginning and end in the log-file.
Version 2020.1

Version 2020.1

We added:

  • Optimization of the model sector creating/inserting operation.
  • The ability to display graphs for the accumulated parameters of markers.
  • The ability to delete all simulated maps.
  • Automatic addition of economic constraints and work factor when importing planned wells.
Version 2019.11

Version 2019.11

We added:

  • display of simulation joints: perforations, fractures;
  • the ability to display graphs for perforations given in depths measured along the wellbore.

Besides, «Well index» cube takes into account simulation joints.

Version 2019.9

Version 2019.9

Improvements:

  • frequently used operations are accelerated;
  • import of planned wells from a CSV file is implemented;
  • in crossplots, when comparing models, an overlay mode is implemented in the History / Calculation axes.
Version 2019.8

Version 2019.8

We implemented:

  • mapping of hydraulic fractures defined in md in the “3D” and “Map” windows;
  • delayed filtering.

Besides:

  • sidetracks of well trajectories are supported;
  • improvements in 3D window.

Version 2019.6

Version 2019.6

Improvements:

  • Operations in the interface are accelerated;
  • Joint display of a histogram on cube and its values in points of wells.
Version 2019.5

Version 2019.5

We added:

  • combined import of well data from the database;
  • comparing histograms and GSR of different models;
  • for GSR the ability to build on the sum, maximum and minimum;
  • custom trend line.

Benefits

In 2007, after passing independent tests, RN-KIM received the Gosstandart of Russia certificate of conformity, this was the beginning of Rosneft using its private hydrodynamic modeling software for preparation and protection of field development design documentation.

High Performance Calculations

With the increase in dimension and complication of hydrodynamic models, the requirements for RAM and computer system performance increase. Speeding up model calculations is a priority for the simulator development. The parallel multithreaded version for workstations allows to reduce the calculation time due to the use of multi-core processors. The simulator is adapted to work on cluster and supercomputer systems. Thus, when calculating on 32 cluster nodes for models with hundreds of millions of cells and tens of thousands of wells, the calculation was accelerated up to 24 times.

Auto-adaptation and Multivariate Calculations

For automatic adaptation tasks, optimization algorithms are used. Using multivariate parallel model simulations, the effectiveness of development systems is evaluated. The optimization criterion is any complex technical and economic parameter, for example, oil recovery ratio or NPV. Other target functions are set using the Python programming language. As a result, with the help of the simulator and routines in Python it is possible to solve a wide range of problems in the optimization of development history (History Matching).

Dual Environments

To simulate filtration in fractured porous reservoirs, the simulator implements a model of double porosity and double permeability. Cracks and blocks of the matrix are considered as two media by embedding one into the other. The flow along cracks, the flow along blocks of matrices and flows between cracks and blocks of matrices are calculated separately. The mechanism of gravity impregnation and drainage was implemented according to the Gilman and Kazemi and Quandalle and Sabathier models. The option is especially relevant for the development of shales, Bazhenovskaya and Domanikov suite.

Simulation Options and “Complex” Well Intervention and Workover
  • Black Oil and Vapor Oil Models
  • Corner point geometry, faults, non-adjacent cells
  • Group well control
  • Aquifers
  • Water-gas injection
  • Polymer flooding
  • Tracers
  • Hysteresis of RPP and capillary forces
  • Horizontal wells with multi-stage hydraulic fractures
  • Multi-segment wells
  • Local grid refinement and coarsening
Automatic Forecast Management

The simulator contains functionality for predictive calculations on the use of group control of wells and economic constraints. The user can determine the automatic actions performed according to a given condition, for example, for editing events of property cubes, using the Python interpreter built into the simulator. The built-in interpreter allows to access the model parameters and simplifies the addition of new options with minimal programming knowledge.

Compatibility with Eclipse, Tempest

The prepost processor supports the Eclipse™ (Schlumberger), Tempest™ (Emerson) data formats and allows to convert the model to the RN-KIM format. Also, the interface allows to load simulations from the formats “RN-KIM”, “Eclipse”, “Tempest” and make comparisons between them.

Integrated Modeling

When modeling gas and gas condensate reservoirs, integrated models of the surface gas collecting system influence on well operation modes are used. For strategic planning while prepairing process design package, RN-KIM offers the option of a simplified integrated modeling NETWORK in Black-Oil formulation. For detailed modeling of the reservoir and gas collecting system up to the entry point to the gas treatment system, the option of joint work with IPM Suite 12.5 by Petex has been implemented. In "RN-KIM + Prosper + GAP" combination Resolve acts as a control process. That is why the process of switching to RN-KIM does not require getting used to another workflow for a user who is accustomed to working with other hydrodynamic simulators in integrated modeling. RN-KIM has been working in conjunction with IPM Suite in Black-Oil formulation since version 2021.1.

Physical and Mathematical Model

3-phase and 3-component Black Oil model

3-phase and 3-component Black Oil model

The basis for solving the problem of filtering a viscous compressible multiphase slurry in a porous medium is the mass conservation equations and variations of the Darcy equation, which take into account the transition of oil and gas components into the liquid and gas phases. A completely implicit time sampling scheme and the Newton method of solving a nonlinear system of equations are used.

Three-Parameter Well Model, taking into account flows along the wellbore

Three-Parameter Well Model, taking into account flows along the wellbore

The implemented model allows taking into account flows along the wellbore for correct modeling of the simultaneous development of several reservoir layers.

Faults and Aquifers

Faults and Aquifers

Faults:

  • pinched-out layers, non-adjacent cells
  • Transmissibility multipliers
  • Threshold pressure

Aquifers:

  • Fetkovich
  • Carter-Tracy
  • constant inflow
  • constant pressure
Dual Porosity / Permeability Model

Dual Porosity / Permeability Model

The flow between the matrix and the crack is due to three mechanisms:

  • fluid expansion
  • capillary impregnation / drainage of matrix blocks
  • gravity impregnation / drainage of matrix blocks

Advanced Functionality

Modeling the Inflow to the Fracture

Modeling the Inflow to the Fracture

To model hydraulic fractures, a method is used based on the conjugation of the finite-difference approximation of the flow in the reservoir and the analytical solution in the vicinity of the fracture. The fracture is modeled as a collection of drains (sources) located one at a time in each simulation block through which it passes.

Local Grid Refinement and Coarsening

Local Grid Refinement and Coarsening

Local grid refinement improves the accuracy of the solution near the wells. Grid coarsening can be used to combine those areas of the reservoir whose modeling accuracy is not significant.

Simulation Speed

Simulation acceleration using GPU

Simulation acceleration using GPU

  • NVIDIA CUDA technology is used;
  • simulation acceleration using GPU: 1.5 to 3.4 times compared to CPU;
  • solving SLAE is ported on GPU;
  • supported only for blackoil models;
  • alternative AIPS preconditioner to improve GPU acceleration.
Acceleration on Cluster Systems

Acceleration on Cluster Systems

For models of more than 2-4 million active cells, it is important to use several cluster nodes to reduce the simulation time. Also, the use of the cluster version allows to remove restrictions on RAM for simulating giant models. In this case, the simulator automatically separates the model grid and provides data exchange along the boundaries.

Multicore Using

Multicore Using

Today, all personal computers have muticore processors. Our simulator parallelizes calculations using threads and achieves good speedup.

Test Compliance

Modeling the Effect of Hydraulic Fracturing

Modeling the Effect of Hydraulic Fracturing

In RN-KIM the inflow to the fracture is modeled by the source method. The results are compared with the grid refinement method, in which the grid cells are ground to the size of the fracture, and high permeabilities are set in the fracture cells.

SPE Test 1

SPE Test 1

  • 3-phase Black oil model
  • 10x10x3 cells
  • Permeability varies by layers
  • Unsaturated reservoir with gas injection into the well

Conclusion: the accuracy of calculations was verified taking into account the effects of gas dissolution, changes in saturation pressure, gravity.

The difference between the calculation of RN-KIM and Eclipse for cumulative production in phases of less than 1%.

SPE 3 Test

SPE 3 Test

  • 3-phase model of Live oil type
  • 9x4x4 cells
  • Permeability varies by layers
  • Injection well injects gas

Conclusion: the accuracy of the calculations was verified taking into account the effects of the deposition of a heavier liquid phase in the formation and the subsequent evaporation of condensate due to the injection of dry gas.

In comparing RN-KIM and Eclipse, the maximum discrepancy in the cumulative integrated characteristics is less than 1%.

SPE 7-2b Test

SPE 7-2b Test

  • 3-phase Black oil model
  • 9x9x3 cells
  • Horizontal permeability 300 mD, vertical permeability 30 mD
  • Injection and production horizontal wells, one above the other

Conclusion: accuracy was verified, less than 1%, on a series of simulations of models with a horizontal well.

SPE 9 Test

SPE 9 Test

  • 3-phase Black oil model
  • 24x25x15 cells
  • Calculation of filtration with complex nonlinear capillary pressure curves
  • 25 random production wells, 1 injection well

Conclusion: when comparing RN-KIM and Eclipse, the maximum discrepancy in the cumulative integrated characteristics is 1%.

SPE 10 Test

SPE 10 Test

  • 2-phase Black oil model
  • 220x60x85 cells;
  • Permeability 0 - 20,000 MD
  • Porosity 0 - 0.5
  • Cell size 6x3x3.6 m

Two-phase filtration in a reservoir with a highly inhomogeneous distribution of porosity and permeability is simulated.

Conclusion: when comparing RN-KIM and Eclipse, the maximum discrepancy in the cumulative integrated characteristics is less than 1%.

Plans for 2022-2023

  • Compositional version development (combination with Network option, version for cluster systems)

  • Accounting for secondary fracturing with PEBI grids

  • Accounting for the rock stress-strain state influence on reservoir properties and express calculation of hydraulic fracture parameters with RN-GRID and RN-SIGMA software

  • Integration with PLT and well test results