Surface BOP—Recent Experience and Future Opportunities

Abstract

Recent application of Surface BOP from floating drilling rigs to drill offshore wells began in early 1996 in the relatively benign environments of Southeast Asia. The techniques and equipment required to use surface blowout preventers from floating rigs have evolved progressively from the initial application in relatively shallow water benign environments using moored semisubmersible rigs to recent application in very deepwater moderate environments using dynamically positioned drilling rigs (Fig 1). While much of the industry focus has been on developing floating surface bop deepwater applications, a significant number of wells have been drilled effectively in shallow water depths using Surface BOP drilling units. The appeal for utilizing floating drilling rig-based surface bop technology in these areas is that the technique can address a number of site-specific issues facing bottom-supported rigs. These include:Bottom-supported rig site assessment issues related to soil conditions.Risk mitigation associated with shallow geo-hazards.Improved operational efficiency compared with conventional subsea BOP or bottom-supported rig alternatives. Additionally availability of an economic alternative to bottom-supported units effectively expands the available rig fleet thereby mitigating possible rig availability project constraints. In addition to providing viable alternatives to bottom-supported drilling units in certain shallow water circumstances, floating drilling rig-based surface BOP is more readily adapted to other emerging drilling methods than a conventional subsea BOP configuration. This paper will:Review current practice with respect to surface BOP application from floating drilling units.Review alternative applications of surface BOP from floating drilling unitsIntroduce surface BOP from floating drilling units as an enabling technology for deploying emerging drilling methodologies and equipment.

Coupled Dynamic Analysis for the Riser‐Conductor of Deepwater Surface BOP Drilling System

“…The conductor and casing string mass per unit length include the mass of the conductor, the surface casing, and the cement sheath between them. The axial force of the riser-conductor can be obtained as in (3). For the riser, the axial force is its effective tension [8,13], while, in general, the axial force on the SID may be tensile and the force on the conductor and casing string is compressive.…”

“…Based on successful drilling campaigns in Asia, Shell extended its SBOP technology to the more demanding offshore operations in Brazil with the implementation of a SID. Unocal and Transocean pioneered the application of the SBOP from floating drilling units, which began in early 1996 in the relatively benign environment of Southeast Asia (Kozicz, 2006) [3]. The deepwater well 1-SHEL-14-RJS (block BM-C-10 in the Campos Basin, offshore Brazil) was successfully drilled in water depth of 2887 m by Shell in 2003.…”