Using Multilaterals to Extend Well Life and Increase Reserves: Case History of an Offshore Thailand Project

Abstract

This paper will detail a recent four-well TAML Level 4 multilateral (ML) installation in a field located offshore Thailand. The drivers that led the operator to seek out a first time multilateral solution for this field development will be covered, along with the variables considered in selecting the specific multilateral system that was ultimately chosen. Both the difficulties encountered and the successes achieved during the multilateral planning, installation and perforating processes will be covered.

Although ultimately successful in all four wells, the multilateral construction process was not without challenges. The shallow depths of the multilateral junctions and the resulting weak formations resulted in a need for maximum mechanical support at the junction. At the same time, the multilateral needed to use a minimum of specialized equipment and processes to meet the timing urgency resulting from the existing rig availability deadline. This short timing made equipment and personnel sourcing a vital factor in the eventual success of the project. The importation of the perforating charges that are used in this ML system was especially challenging and must be taken into greater consideration when planning future installations.

At the end of the project, the success of the installations was due in large part to the simplicity and reliability of the ML systems used, but another key factor in the success was the necessary and careful coordination of planning and activities between the operator and the service company providers involved in the multilateral construction process. The historical perception in the petroleum industry has often assumed that multilaterals require extensive lead times and that operating companies without previous multilateral experience face a steep learning curve to achieve successful results. The success of this project, however, demonstrates that today's multilaterals can be reliable and simple enough to consider even when time requirements are tight and in areas where multilaterals are considered a "newer" technology.