chapter 10, Practical Topics in Reservoir Simulation

Excerpt

This book has concentrated on the development of reservoir simulators using finite difference methods. These methods can be replaced by other discretization methods such as finite volume and finite element methods. In this chapter we discuss some practical topics that must be addressed at certain stages in petroleum reservoir simulation, no matter which discretization methods are used. The major steps in areservoir simulation study are sketched in Fig. 10.1, with more details given in Table 10.1. Here we briefly touch on some of the basic elements of the simulation study: design of study objectives, analysis of reservoir data, development of simulation models, selection of simulation grids, history matching, and prediction of reservoir performance. Other practical topics such as upscaling, recovery optimization, and surface network systems can be found in Chen, Huan, and Ma (2006).

10.1 Design of Study Objectives

The main goal of reservoir simulation is to predict future performance of a reservoir and find ways and means of optimizing the recovery of some of the hydrocarbons under various operating conditions. Its major study objectives involve estimating fluid movement and storage, impact of operating strategies, distribution of fluid and heat, production profiles for profitability decision making, reservoir management, and evaluation and design of novel production technologies. The design of these study objectives is the most crucial and fundamental step in the application of any reservoir simulator. They dictate the scope and type of the simulation model to be employed, the amount of company resources to be allocated, the quality of history matching to be performed, and the type of prediction cases to be made.

The design of study objectives depends on the stage of hydrocarbon recovery of the subject reservoir (the appraisal (preproduction), primary, secondary, or enhanced recovery stage), the quantity and quality of available production and reservoir data, and time frames. For example, (1) in the appraisal stage, the available data from the drillstem tests from exploration and appraisal wells are very limited and can be used solely for a preliminary history matching of the reservoir model; the objectives in this stage may include the determination of the range of reserves and timing of production for the field.