Surface BOP: Testing and Completing Deepwater Wells Drilled With a Surface-BOP Rig

Abstract

Summary Many deepwater-development projects in operators' portfolios require lower costs to meet internal economic thresholds. Because of this, Shell has looked at extending surface-blowout-preventer (BOP) activities to include well testing and completion techniques for deepwater wells in conjunction with surface-BOP drilling. The cost advantages of surface-BOP-drilled wells have been demonstrated (notably in the Far East), but the recent surface-BOP-drilled well in Brazil is a milestone in terms of extending the applicability to deeper water and harsher environments. The enabling technology has been the subsea isolation device (SID). Testing and completion techniques have been developed to be compatible with surface-BOP wells drilled with an SID. This paper focuses on the following aspects: Well testing using surface-BOPs from a moored rig and Well completions using surface-BOPs from a moored rig. Shell has developed a testing configuration to carry out a DST, essentially using standard equipment. The well-testing equipment configuration is currently ready for use and has been run in a subsea-BOP well. In completion operations, the availability of a high-pressure (HP) riser does not add significant complexity and even actually simplifies some of the completion activities. Conceptual studies and early hazard/risk assessments have shown there are no obvious "showstoppers," and the duration of a surface-BOP-rig completion is expected to be very similar to a subsea-BOP-rigcompletion. This paper describes the results of the conceptual studies, early hazard assessment exercises used to define the basic design parameters, and more detailed hazop studies.