Fully coupled simulation for fluid flow and geomechanical properties in oilfield simulation operations

A computer implemented method for modeling an oilfield having a subterranean formation and an underground reservoir therein, the method comprising:

• modeling, using a computer, the oilfield based on a geomechanical model comprising a viscoplastic model for calculating plastic strain based on a current yield surface;
• obtaining, using the computer, a current stress using the viscoplastic model;
• using a plurality of iterations for achieving convergence;
• determining, using the computer, an incremental change in the plastic strain for at least one of the plurality of iterations, based on a distance of the current stress from the current yield surface.

A computer implemented method for modeling an oilfield having a subterranean formation and an underground reservoir therein, comprising:

• modeling, using a computer, the oilfield based on a geomechanical model comprising a viscoplastic model for calculating plastic strain based on a current yield surface;
• calculating, using the computer, damage to the subterranean formation based on plastic strain;
• modeling sand generation based on damage;
• calculating, using the computer, permeability based on plastic strain and damage;
• modeling sand transportation based on the permeability;
• forecasting, using the computer, production based on the sand generation and the sand transportation.

A computer implemented method for modeling an oilfield having a subterranean formation and an underground reservoir therein, comprising:

• obtaining, using a computer, a statistical size distribution of a plurality of pores located in the subterranean formation;
• establishing a fluid flow model based on an interconnected pipe network for representing the plurality of pores, the interconnected pipe network having network geometry determined based on the statistical size distribution;
• adjusting, using the computer, the interconnected pipe network based on a stress/strain change in the subterranean formation to generate an adjusted network geometry;
• and
• updating, using the computer, the fluid flow model based on the adjusted network geometry.

A computer implemented method for modeling an oilfield having a subterranean formation and an underground reservoir therein, comprising:

• modeling, using a computer, the oilfield based on a geomechanical model for representing at least a portion of the subterranean formation and the reservoir, the geomechanical model comprising a stress equation and a fluid flow equation;
• configuring, using the computer, a neural network associated with the geomechanical model, the neural network being configured for at least one selected from a group consisting of:
• processing input data, by assigning data related to stress and material properties as inputs to the neural network and generating a set of values to be assigned to an array of individual grid blocks representing a portion of the oilfield modeled by the geomechanical model;
• calculating strain and plasticity, by assigning loads and elastic stiffness matrix for stress equations at a given time as inputs to the neural network and generating plastic and elastic strain throughout the array of grid blocks representing the portion of the oilfield modeled by the geomechanical model;
• analyzing well placement and schedule, by assigning various choices of well trajectory and production and injection schedules as inputs to the neural network and generating simulation outputs for a revised set of parameters;
• and
• resimulating based on revised input data by assigning changes in material properties or observed stress and strain as inputs to the neural network and generating simulation outputs with revised properties.