# Reservoir Simulation

## Chapter 6 – Numerical Methods in Reservoir Simulation Learning Objectives

*Write down from memory simple finite difference expressions for derivatives etc. Define the meaning of the forward difference, the backward difference and the central difference and the order of the error associated with each, O(Δx) or O(Δx2). Explain spatial and temporal notation.

A finite difference scheme is a way of approximating derivatives of a function.

The forward difference takes the slope between Pi and Pi+1 as its approximation

The backward difference takes the slope between Pi and Pi-1 as its approximation (more…)

## Chapter 4 – Gridding and Well Modelling Learning Objectives

*Understand and be able to describe the basic idea of gridding and of spatial and temporal discretization

Gridding is the process of dividing the entire reservoir up into small spatial blocks which then compromise the units on which the numerical block to block flow calculations are performed. This is known more formally as spatial discretization.

There is also the process of dividing up blocks into time steps (Δt) and this is referred to as temporal discretization. (more…)

## Chapter 3 – Reservoir Simulation Model Setup Learning Objectives

The textbook asks a few questions that aren’t directly answered  in material, so this section is complete. I’ll get to work on filling in the blanks but for the time being here it is.

*Identify what questions the simulation is expected to address

*Identify what data is required as input to perform the desired calculations

Most data files will be separated into the following areas:

• Model dimensions
• Grid and rock properties
• Fluid properties
• Initial conditions
• Output requirements
• Production schedule

Individual parts of the input data can also be setup by programs and this falls under pre-processing.

Pre-processing may be used to: (more…)

## Reservoir Simulation Learning Objectives Chapter 2 – Basic Concepts In Reservoir Engineering

*Be familiar with the meaning and use of all the usual terms which appear in reservoir engineering such as , Sw, So, Bo, Bw, Bg, Rso, Rsw, cw, co, kro, krw, Pc etc.

• Sw – water saturation.
• So – oil saturation
• Bo – oil formation volume factor
• Bg – gas formation volume factor
• Bw – water formation volume factor
• Rso – solution gas oil ratio
• Rsw – solution gas water ratio
• Cwcompressibility water
• Cocompressibility oil
• Cfcompressibility formation
• Krorelative permeability oil
• Krwrelative permeability water
• Pccapillary pressure

## Reservoir Simulation Learning Objectives Chapter 1 – Introduction and Case Studies

*Be able to describe what is meant by a simulation model, saying what analytical models and numerical models are.

Simulation models are a representation of a real system and because of their simplified nature, allow calculations to be made giving insight into the real system.

Analytical Models are defined by their ability to be solved by using mathematical techniques.

Numerical Models are defined by the complexity in solving their equations and are usually carried out by a computer. Numerical models approximate the real model by carrying out a large number of calculations across unit steps of interest (time steps for example). (more…)