Popeye Project: Subsea System
Authors: Ritter Paul B. , Langner Carl G. , Sgouros George E. , Saucier Brian J. , Voss Robert K. 
Published: October 2008

The subsea system installed for Shell Offshore Inc. (S01) Popeye Project represents an advancement in deep water subsea technology. It is a diverless, guideline less, 10,000 psi cluster manifold concept, the first of its kind. The cluster concept was selected in large part based on S01's deep water experience and anticipated future subsea development needs. This paper describes how the innovative Popeye subsea system was selected, designed, tested, and successfully installed.

Introduction

Field development studies for Popeye indicated that a satellite subsea development scheme was the only economical alternative. The required subsea technology existed, but Popeye presented a unique combination of challenging technical requirements together with its marginal economic potential. S01 also recognized that those requirements, primarily high pressure, deep water, and long offset distance, would increase and continue to be challenges for its many other deep water prospects. These considerations called into question whether the existing, traditional subsea system designs, adapted as required for Popeye's technical needs, were the best solution for Popeye and the future.

A subsea system concept utilized in diver depths in the North Sea, called the cluster manifold concept, seemed to offer advantages for deep water Gulf of Mexico (GOM). The cluster concept has discrete satellite subsea wells m close proximity to a common manifold, connected to the manifold with flowline and controls jumpers However, the 'diverless' jumper technology required for a deep water cluster concept had not been field proven. In deep water, without the use of divers, the concept depends on the ability to interconnect components using only remote tools from a surface vessel and/or Remote Operated Vehicles (ROVS), It also requires accurate remote positioning and measurement of wells and structures on the seafloor.

But there were several reasons to have confidence that a diverless cluster concept was viable for Popeye: experience gained by S01 in deep water guideline less drilling; routine utilization of rapidly advancing ROV capabilities; and encouraging results of Shell research on deep water flowline installation methods. A comprehensive comparison was carried out between the cluster concept and the traditional integrated template subsea system, The cluster concept was judged The best solution, and a conceptual model was developed as a basis for project execution (Fig. 1).

Design Requirements/Philosophies

Based on subsurface and systems engineering studies, including technical and commercial considerations, design requirements and philosophies were established for the Popeye subsea system. These served as the basis for selecting the best system concept and for subsequent technical specification and design of [he subsea system, Some of the significant requirements and philosophies are as follows:

Design Requirements:

2 initial wells; up to 6 wells total 60 Mmcf/d per well; 120 Mmef/d total system 10-15 years field life 2040 ft. water depth 6800 psi shut-in tubing pressure Mildly corrosive gas with only water of condensation