Reservoir Engineering & Simulation Print E-mail

3D-Geo uses the following work-flows when conducting reservoir engineering and simulation:

    3D Reservoir Modeling Work-Flow 1

    3D Reservoir Modeling Work-Flow 2
•Review field history
•Review petrophysics (log interpretation, routine and special core analysis, natural fractures)
•Review well data (MDT, DST, production tests)
•Review geologic model

    3D Reservoir Modeling Work-Flow 3
•Static to dynamic model
–Regional Model (100+ million cells); assists in areas with data holes
–Structure and stratigraphy static model (1+ million cells)
–If required, up-scale to dynamic model (100,000+ cells)

•Define reservoir fluid properties (PVT lab studies) – black oil or compositional?
•Obtain, check & load, production and injection data (test data and allocated data); account for missing data (data holes)

    Example 3D-GEO Production and Faulting

    3D Reservoir Modeling Work-Flow 3 Continued
•Obtain, check & load, pressure data (well-head and subsurface, flowing and static). Define initial reservoir pressure at datum depth.
•Conduct analytical analysis of data (eg material balance) to assess reservoir drive mechanism and state of depletion. Assess aquifer size and connectivity.
•What type of model is needed (eg. carbonate dual porosity)?
•Define fluid contacts (range of uncertainty? MDT, logs, AVO)
•Define capillary pressure and relative permeability by rock type
•Initialize dynamic model and ensure it is in static equilibrium.
•Check OOIP, OGIP and OWIP with static model.

    3D Dynamic Model is Now Built
Next steps:
•Define wells: location & vertical flow performance (VFP)
•Account for missing production data
•History-match reservoir and well performance
•Sensitivity analysis: which parameters have largest impact ? – Feed-back to G & G modeling team
•Define model boundary conditions

    Predictive Runs
•Once the model has been history-matched, predictive runs can be done
•Future production under “Do Nothing” case, or “Business As Usual” case.
•Alternative development strategies, for example:
–Work-over and stimulation options (eg. acidizing, fracturing, tubing size and artificial lift optimization)
–Infill drilling (vertical, deviated or horizontal wells?) Where & when?
–Secondary recovery (eg. water injection). Location of injectors, well design, when?
–Tertiary recovery (eg. CO2 injection). Location of injectors, well design, when?

    Simulation Output
•Simulation output for the base case, sensitivity cases and all tested alternative development scenarios includes:
–Oil, gas and water production as a function of time for all wells
–3D spatial distribution of saturations (O, G and W) and pressure. (This enables volumes of un-swept moveable oil to be located and targeted.)
Example: Sensitivity to Fracture Permeability
(Base Case in red vs. Low Fracture Permeability in green)

    Sensitivity Study
•Sensitivity runs are made to determine the key reservoir parameters

    Simulation Impacts on MDP
•Work-over and stimulation plan
•Infill drilling plan(horizontal wells?)
•Water injection plan
•Surface facility modifications
•Economic evaluation
•Data trade suggestions to cover data holes