A new generation of multilateral well enhances small gas field economics

by Atse, Jean-Philippe

Abstract (Summary)
The main objective of this study is to investigate the applicability of a new multilateral well architecture in the domain of small size and offshore gas fields. The new architecture completely reverses the current multilateral technology. The innovative concept suggests that laterals can be achieved like any conventional wells. They could be drilled from the surface and tied back to a common wellbore referred to as the mother well. Production would go through the toe of laterals into the mother well. The mother well could be as simple as a large diameter casing equipped with prepared connections to tie in feeder wells. This study looked past the mechanical challenge of achieving the new architecture. I demonstrated important benefits in terms of cost reduction, well completion and operations, and reservoir drainage. I looked at a typical field case, Phoenix, located in West Africa. Its actual development plan targets an ultimate recovery of 600 BCF with a total of four sub-vertical wells. I implemented a new development scenario with the innovative multilateral architecture. For comparison purposes, I achieved a reservoir simulation and a production forecast with both scenarios. The only simulation variable was the well architecture definition. As a main result, the new multilateral structure could produce as many as four vertical wells with three slim-hole laterals. I achieved a quantitative risk analysis on both development plans. I assessed the development cost of each scenario and performed a Monte Carlo simulation to account for cost uncertainties. In addition to the actual 70 MMSCFD gas contract, I simulated a progressive gas demand increase of 20 MMSCFD every five years and a 150 MMSCFD gas market. The study demonstrates the economic benefits of the new technology in the domain of offshore and small gas fields. This work also shows that this new generation of multilaterals brings new option values to the domain of multilateral technology.
Bibliographical Information:

Advisor:Startzman, Richard A.; Leggett, John; Valko, Peter P.

School:Texas A&M University

School Location:USA - Texas

Source Type:Master's Thesis

Keywords:multilateral gas field economics simulation slim hole


Date of Publication:12/01/2003

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