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  • RESERVOIR SIMULATION - A BASIC TOOL OF RESERVOIR MANAGEMENT

    1/3/2018 DR. HELMY SAYYOUH 1

  • Use of fine-grid reservoir models can translate laboratory results to field applications.

    1/3/2018 DR. HELMY SAYYOUH 2

  • Simulation of Oil Recovery Methods With Finite Difference Simulators.

    Reservoir Rock Idealizations

    Single Porosity: described by a normal distribution function in each geologic layer.

    Dual Porosity: where two distinct types of porosity coexist in a representative rock volume such as naturally fractured reservoirs.

    1/3/2018 DR. HELMY SAYYOUH 3

  • Single Permeability: fit a log-normal distribution function in each geologic unit.

    Dual Permeability: is the idealization of the reservoir systems where both the matrix and fracture network have continuity and transmissivity is not insignificant compared to that of the fracture.

    1/3/2018 DR. HELMY SAYYOUH 4

  • Reservoir Fluid Classification

    Black Oil: the critical point is far to the right of the bubble point.

    Volatile Oil: Bubble-points are fairly close to the critical point.

    Gas Condensate: the critical point is to the left of the reservoir dew point.

    1/3/2018 DR. HELMY SAYYOUH 5

  • Wet Gas: solely exists as gas in the reservoir without condensing any liquids. In surface separators, liquids are formed.

    Dry Gas: exist as gas in the reservoir and in the surface

    1/3/2018 DR. HELMY SAYYOUH 6

  • Enhanced Oil Recovery

    Primary and secondary oil production: are simulated by black oil or compositional formulations.

    1/3/2018 DR. HELMY SAYYOUH 7

  • Enhanced oil recovery

    aimed primarily at reducing the water flood residual oil.

    The most notable of these processes are steam injection, polymer or alkaline water flood, micellar-polymer flood, and miscible gas flood.

    1/3/2018 DR. HELMY SAYYOUH 8

  • Window Modeling, Local Mesh Refinement, and Non-neighbor Connections

    It is practice to model a window area of a reservoir using a fine grid system.

    Boundary conditions of the window area are hard to determine. One solution to this problem is to use the local mesh refinement in the window area while using coarse grid in the rest of the field.

    1/3/2018 DR. HELMY SAYYOUH 9

  • Non-neighbor connections are used to connect nodes for two different but adjacent layers on both sides of a fault.

    1/3/2018 DR. HELMY SAYYOUH 10

  • Infill Drilling and Well Recompletion

    Infill drilling in San Andres carbonates has resulted in recovering large amounts of by water flooding.

    1/3/2018 DR. HELMY SAYYOUH 11

  • Fine gridding

    a. track water-oil interface.

    b. evaluate the possible benefits of a perforating recompletion program.

    c. determine the optimal location of infill wells.

    1/3/2018 DR. HELMY SAYYOUH 12

  • Reservoir Simulation As An Aid To Reservoir Description

    1. Reservoir heterogeneities:

    generally we rely on the development or production geologists to describe the reservoir and build up a geological model that can be used to construct a mathematical model of the reservoir.

    1/3/2018 DR. HELMY SAYYOUH 13

  • 2. Fine Vs. Coarse-Grid Simulation

    Example:

    Inverted five-spot water flood pattern.

    1/3/2018 DR. HELMY SAYYOUH 14

  • 3. Accuracy and Reliability of Finite-Difference simulators

    Numerical errors: truncation errors, round off errors, and numerical dispersion.

    Coarseness of the grid and time step size could cause errors: future may solve this problem by super computers.

    1/3/2018 DR. HELMY SAYYOUH 15

  • Conclusion

    Combination of new super computers and fine- grid models: will provide the capabilities to resolve reservoir heterogeneities and location of by-passed mobile oil in the reservoir.

    1/3/2018 DR. HELMY SAYYOUH 16