Simulations in Digital Rock Physics & Digital Core Analysis

Decisions regarding the development and production of oil and gas reservoirs are guided by reservoir models. Making the correct decision depends on how good the models are and how fast such models can be generated. The accuracy of such models depends largely on the quality of the physical rock properties used to generate the models. Therefore, fast and accurate core analysis is of paramount importance for such decisions.

Rock properties are determined either through physical core analysis in a laboratory or by numerical core analysis using simulations, also called Digital Rock Physics.

Digital Rock Physics (DRP) is an innovative technique for numerical core analysis in the Upstream sector. For the following aspects, it enables:

• E&P (Exploration & Produktion):
  Automation of Routine Core Analysis (RCAL),
  Predictions for management decisions
• R&D (Research & Development):
  Performing Special Core Analysis (SCAL),
  Development of new workflows,
  DRP projects,
  Gaining new insights on rock properties
• EOR (Enhanced Oil Recovery):
  Improving recovery rates (e.g., Water Flooding)

The input data from DRP are used to calculate, for example, the permeability throughout the reservoir model (modeled at the kilometer scale). Based on these simulations, further decisions for production from this reservoir can be made, e.g. the placement of new production wells.

DRP offers the following advantages when compared to laboratory analyses:

• enormous time and cost savings through targeted placement of new wells for drilling 
• performing multiple numerical experiments on exactly the same sample (non-destructive technique)
• conducting different analyses simultaneously on one sample
• investigation of rock properties under multiple scenarios
• testing of different production strategies and improving recovery scenarios

Computer simulations with GeoDict help reservoir engineers and geoscientists to digitalize and automate the analysis of physical rock properties. GeoDict outputs the following:

• Geometric properties: porosity, pore size distribution, percolation, Minkowski parameters, surface area, tortuosity, pore sphericity, pore shape
• Flow properties: absolute permeability, upscaling of flow, multi-phase flow, relative permeability, capillary pressure curve
• Electrical properties: Formation factor, resistivity index, saturation exponent, cementation exponent
• Mechanical properties: Elastic moduli, stiffness, in-situ conditions

Through the computer simulations with GeoDict, new insights into the processes going on in the rocks are retrieved and will help to understand the causes for uncommon behavior of hydrocarbon reservoirs. 

Running computer simulations with GeoDict can be used to:

• compute the physical rock properties determined during Routine Core Analysis (RCAL) and Special Core Analysis (SCAL).
• evaluate the quality of laboratory based analyses.
• simulate reactive transport like carbonate dissolution.
• predict the results of experiments in microfluidics systems.
• analyze the geometrical properties of rocks (pore space, grains).

The material properties of rock samples under in-situ conditions are also determined through digital analysis and the simulation of pressure and temperature conditions.