Multi-scale Geomechanics: How Much Model Complexity is Enough?

Transcription

1 SPE Workshop OILFIELD GEOMECHANICS Slide 1 Multi-scale Geomechanics: How Much Model Complexity is Enough? Alejandro Ganzo Geomechanics Support Engineer March 27-28, 2017 Moscow, Russia

2 Slide 2 Car Requirements Pinthiscar.com Kbb.com Truckin.web

3 Modeling requirements Slide 3 Address the geomechanical challenge Avoid costly NPT Reduce risk Don t overspend resources Time Computation power Software license costs Optimum effectiveness and efficiency Kick Stuck pipe NPT Safe Mud Window Salt Exit Surprises Optimizing drilling direction Wellbore failure Lost Circulation Unplanned Sidetrack Optimizing casing point

4 Slide 4 Geomechanical Modeling Wellbore Scale Modeling Reservoir Scale Modeling Calibration 1D Model 3D Model 4D Model Pore Pressure LOT Breakout Lost circulation Lab tests Rock prop s Overburden Pore Pressure S hmin & S Hmax Fracture Grad Rock prop s Overburden Pore Pressure S hmin & S Hmax Fracture Grad Changing Pp Changing T Complex structure Complex material Points 0D Logs 1D Static 3D Dynamic 4D

5 Geomechanical Modeling Slide 5 Modeling techniques Wellbore-scale calculation (1D) Reservoir-scale calculation (3D) Reservoir-scale simulation (4D) Example 1D Wellbore-scale model

6 Geomechanical Modeling Slide 6 Modeling techniques Wellbore-scale calculation (1D) Reservoir-scale calculation (3D) Reservoir-scale simulation (4D) 1D Wells & 3D Structure Build 3D Grid Method described in: SPE MS, SPE MS Populate 3D Grid

7 Geomechanical Modeling Modeling techniques Wellbore-scale calculation (1D) Reservoir-scale calculation (3D) Reservoir-scale simulation (4D) Finite Element Model Slide 7 Structural Model Flow Simulation Model Geomechanical model Stress & strain through time

8 Objective Slide 8 The objective of this presentation is to compare different geomechanical modelling techniques for their applicability and resource efficiency in different structural settings. We are comparing the stresses calculated using 1D, 3D and 4D geomechanical models Method in two different settings: Continental shelf with a benign slope Submarine canyon

9 Slide 9 Method Geological setting: Continental shelf (simple) Submarine canyon (complex) Model size Region 180 x 150 km Submodels 32 x 32 km Stress regime Normal Faulting Sv>SHmax>Shmin Shmin perpendicular to coast SHmax parallel to coast

10 Slide 10 Methods Continental Shelf Model Description: Simple geometry Depth seafloor m Wells Vertical well E (TD 2650m) Deviate well F (TD 2250m) Area of interest: Top 2.6 km surrounding wells Total depth 5.5 km

11 Slide 11 Methods Submarine Canyon Model Description: Complex geometry Depth seafloor m Wells Vertical wells A, C & D (TD 2650m) Deviate well B (TD 2250m) Area of interest: Top 2.6 km surrounding wells Total depth 5.5 km

12 Methods Wellbore Scale Models Slide 12 1D Model Input High resolution wire line data P p S hmin S Hmax S v Pp: hydrostatic 1030 kg/m3 Sv: integration density Shmin: ESR=0.5, perpendicular to coast SHmax: ESR=0.7, parallel to coast Resources required Project time Computation power Relatively short Low

13 Slide 13 Methods Reservoir Scale Static Model 3D Model Input Structural framework: horizons, bathymetry Grid resolution: lateral 650m, vertical 50m Density, Poisson s and Young s upscaled from wells Stresses and pore pressures are calculated Pp: hydrostatic 1030 kg/m3 Sv: integration density Shmin: ESR=0.5, perpendicular to coast SHmax: ESR=0.7, parallel to coast Resources required: Intermediate Density

14 Methods Reservoir Scale Dynamic Model Slide 14 4D Model Input Structural framework: horizons, bathymetry 3D Mesh resolution: inside fine, outside coarse Density, Poisson s ratio and Young s modulus from 3D Grid Pp: hydrostatic 1030 kg/m3 Simulation instead of Calculation ESR 0.5 and 0.7 on outside model Density, elastic moduli and Pp inside model Model initialization Resources required: High Density

15 Methods Rock Properties Slide 15 Geomechanical properties populated from: 1D model to 3D model 3D model to 4D model 1D model: high resolution 3D model: coarser 4D model: lowest resolution

16 Next Stress Results Slide 16 Stresses of the 3D and 4D model are mapped on the wellbore trajectories for comparison. C B Example results

17 1D vs 3D Model Continental Shelf Slide 17 E F S v (MPa) 3D Model 1D vs 3D: Continental Shelf Vertical Well E Deviated Well F Good match Good match

18 Slide 18 1D vs 3D Model Submarine Canyon C B S v (MPa) 3D Model 1D vs 3D: Continental Shelf Vertical Well C Deviated Well B Good match Bad match

19 Slide 19 1D vs 3D Model Submarine Canyon 3D Model 1D Model water 0.2 km B 1.4 km water S v? rock 2.0 km 1D model: inaccurate stresses at complex topography above deviated wells 0.8 km rock S v =34 MPa S v =43 MPa

20 Slide 20 3D vs 4D Model Continental Shelf E F S v (MPa) 3D Model 3D vs 4D: Continental Shelf Vertical Well E Deviated Well F Good match Good match

21 Slide 21 3D vs 4D Model Submarine Canyon B D B S v (MPa) 4D Model 3D vs 4D: Continental Shelf Vertical Well D Deviated Well B Bad match Bad match

22 Slide 22 3D vs 4D Model Submarine Canyon

23 Slide 23 Implication of Results Complex structure: Submarine Canyon Model Result Resources 1D Wellbore Very Inaccurate Small 3D Reservoir Inaccurate Intermediate 4D Reservoir Accurate Large Complex Geological Setting 1D and 3D models give different inaccurate stresses compared with the 4D models Complex structures: 4D reservoir-scale model is required for accurate result even though required time, computation power, and software are expensive.

24 Slide 24 Implication of Results Simple structure: Continental Shelf Model Result Resources 1D Wellbore Accurate Small 3D Reservoir Accurate Intermediate 4D Reservoir Accurate Large Simple Geological Setting All three modeling techniques give comparable, accurate results For simple structures consider using a more efficient method (1D or 3D) to save time, computational power and software license costs 1D model save significant time on modeling that can be used for better analysis of result, QRA, sensitivity or uncertainty analysis

25 Slide 25 Conclusions Complex Structures 1D and 3D model don t produce accurate results 4D geomechanical model necessary Simple Structures All three modeling techniques give accurate results 1D model effective and efficient method, high resolution 4D model large expenditure of resources, low resolution Initial step in geomechanical study: Assess complexity of setting Choose modeling technique that balances accuracy and cost effectiveness

26 Slide 26 Thank You - Questions? 3D Geomechanical Models 4D Geomechanical Models

27 SPE Workshop OILFIELD GEOMECHANICS Slide 27 Multi-scale Geomechanics: How Much Model Complexity is Enough? Alejandro Ganzo Geomechanics Support Engineer March 27-28, 2017 Moscow, Russia