Optimisation of Intelligent Wells in a Reservoir Simulation Model - Part 2

Abstract

This work is the second part of a project to investigate what is possible in terms of control and optimization of a multi-lateral well within a greater field model, using the proprietary reservoir simulator Eclipse. In this part procedures were developed and tested using either ACTION keywords or the OPTIMIZE function to control the downhole chokes via WSEGVALV keywords. The first part of the work was described in a TPG4530 Reservoir Simulation Project of the same name.

The most effective means of modelling choke-control in Eclipse was found to be an ACTIONX procedure triggered by fluid densities. This gave reasonably good manipulation of the downhole chokes to prolong the period of natural lift, which had been identified as a priority by Statoil. Watercut had also been tested as a trigger but proved to be ineffective.

By the use of WSEGVALV and actual valve Cv values it should be possible to compare the simulation results with actual data from the DIACS system, thus determining when the real downhole valves should be adjusted and by how much.

Another procedure was developed based on OPTIMIZE but was found to be too limited in the choice of variables that can be used, notably the absence of fluid density as a constraint. Besides this OPTIMIZE could not be fully tested due to the very large computing requirements and associated problems with computer availability.

This project was proposed and supported by Statoil A/S, principally Dr. V. Haugse, E. Bakken, K. Christoffersen and F. Munkvold who’s kind assistance is gratefully acknowledged. Likewise my gratitude is expressed to my supervisor Prof. J. Kleppe, J.I.Jensen and E.Våtevik at NTNU IPT for their guidance and help.