A General Purpose Model for Multiphase Compositional Flow Simulation

Abstract

Reservoir simulation has come a long way since its birth in the 1950s and now is an important tool for reservoir engineers to predict oil and gas production and optimize reservoir management. In the past, many existing models were developed to simulate fluids with a specific fluid characterization such as black oil, compositional and thermal models. Today, the need for optimizing reservoir life with different recovery techniques and different fluid characterizations is urgent to fully evaluate oil and gas fields assets. In this paper, a flexible general purpose model has been developed for multiphase isothermal or thermal compositional flow simulation in porous media, including formulations, phase behavior calculation, various numerical techniques. Based on general mass balance equations and energy balance equations, a mass variable set has been chosen for the generality for all types of fluids (black-oil, compositional and thermal) to ensure that each grid block has the same amount of primary unknowns and it is convenient for Jacobian matrix construction. The model decouples fluid and formulation from the rest of simulator and makes is possible to model different reservoir physics in one single simulator. The model have tested and validated on various standard comparative benchmark problems like black-oil model, compositional model as well as large complex field cases with over one million grid blocks and an actual reservoir simulation. The test results show that the simulator is comparable with current commercial simulators in accuracy and speed. When different recovery techniques are used in a reservoir life cycle, the model is more efficient and accurate without the need of switching simulators. The generic and modular design architecture provides convenience for extensions of modeling additional flow processes and implementing new numerical solution methods. Developing a general purpose reservoir simulator is the main focus in state-of-the-art reservoir simulation research. The proposed general purpose model for multiphase compositional flow simulation in this paper is one step closer to the goal.

Numerical Approach of a Coupled Pressure-Saturation Model Describing Oil-Water Flow in Porous Media

“…A comparison of the results obtained with both models can be found in [3], where numerical simulation was performed by means of a discontinuous Galerkin method for mass transport, coupled with an implicit mixed hybrid finiteelement (FE) scheme for computing pressure and velocity fields. A flexible general purpose model for multiphase isothermal or thermal compositional flow simulation in porous media was introduced in [40], where numerical simulation results were validated using classical benchmark problems based on black-oil and compositional models. Most of the numerical schemes commonly used in this context are based on finite-difference and FE numerical methods.…”

Research on multi-phase flow test and flow simulation test in energy enterprise automation

“…The measurement is mainly carried out from the hydrate formation area, decomposition rate (Li et al, 2021b), deposition characteristics and blockage formation mechanism, and the hydrate deposition rate at each location in the oil pipeline is determined, so that corresponding measures can be taken to ensure the normal exploitation and transportation of oil; A hydrate-containing multiphase flow model was established to analyze the thermal resistance effect of hydrate blockage on oil pipelines. Based on the continuity equation (Zhang et al, 2022), momentum equation and energy equation (Aglave et al, 2015), the relationship between the three phases of water is established; the multiphase flow model of oil, gas and water is established, and the boundary interface coefficient value of each phase is clarified (Wu et al, 2018). In the experimental test, the minimum critical superficial liquid velocity between laminar flow, wavy flow and slug flow is obtained as 0.113 m/s.…”