Norway's Statoil is sending out an invitation to tender for a new type of drilling rig. It is specially designed by the industry on behalf of Statoil for mature fields on the Norwegian continental shelf (NCS). The purpose is to make drilling and completion of production wells less expensive, more effective and safer, and thereby boost oil recovery.
The specially-designed category D rig is able to operate at water depths of 100-500 m and drill wells down to 8,500 m. It will be a workhorse on mature fields, primarily for drilling production wells and well completion.
"Discoveries on the NCS are getting smaller and it is becoming more important to increase drilling activity in mature fields to attain the full potential of the NCS," says Statoil. "The key to maintaining today’s production level on the NCS towards 2020 is improved recovery from existing fields and fast and effective development of new fields. In order to implement these measures it is crucial that we secure a rig fleet which is adapted to suit the assignments and which can work more effectively."
Statoil has therefore developed a new mobile offshore drilling unit concept, cat D. This rig will be customized for year-round production drilling in mid-water depths. The goal is that the new rig will perform operations 20 percent more effectively than conventional rigs.
Hull designers, topside suppliers, construction yards and drilling contractors have participated in the development of the cat D rig concept.
The cat D conceptual design has the following key elements:
- Large available deck areas for completion logistics
- Excellent motion characteristics which reduce unproductive time, for instance waiting on weather
- Reduce rig time spent on critical line thanks to: 1.5 derrick for simultaneous drilling and building stands; 1.5 moon pool trip saver for hanging off blow out preventer (BOP) and riser in the moon pool when
- running xmas tree (XMT), offline service deck flush with drill floor, enabling all completion equipment interfaces with drill floor
- Separate completion and drilling fluid system in order to convert directly from drilling fluid to completion
- fluid mode without having to clean up the system
- High level of redundancy in material handling, crane coverage and pipe handling
Statoil’s key focus is on safety and production. This rig category is designed to prevent falling objects and it has high reliability in well control systems. It is also designed to prevent environmental spills and assure improved working environment.
In the market process for cat D, Statoil is asking for offers for a
- 8-year firm contract period, including options for 4x3 years, and
- 20-year firm contract period for the rigs; a long term sourcing approach, securing rig capacity fit for Statoil’s growth ambitions as well as securing predictability for the drilling contractor.
Rig entrepreneurs with operational experience on the NCS have been invited to tender for minimum two rigs, based on the cat D design specially-designed by the industry on behalf of Statoil. The invitation to tender (ITT) was sent out to the prequalified rig entrepreneurs on February 21, with planned contract awards in the third quarter of 2011.
To reduce risk and secure yard capacity when the contracts are awarded, Statoil has reserved slots at four construction yards that have the proven construction record Statoil requires to be able to build the rigs within the expected delivery time:
- Daewoo Shipbuilding & Marine Engineering Co. Ltd (DSME) - Korea
- Samsung Heavy Industries (SHI) - Korea
- Keppel FELS Ltd. - Singapore
- Jurong Shipyard Pte. - Singapore
The project’s planning has taken one year and the execution period (detail engineering, construction and transportation to the NCS) is planned to be completed within three years.
- Invitation to tender (ITT)Q1, 2011
- Contract award to drilling contractorQ3, 2011
- Delivery of units to well location on NCS 2nd half of 2014
May 3, 2011