Cat D – new tailor-made rigs
Statoil has issued an invitation to tender for a new type of drilling rig 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.
Cat D in brief
The specially-designed category D rig is able to operate at water depths up to 1300 metres and drill wells down to
8,500 metres. It will be a workhorse on mature fields, primarily for drilling production wells and well completion.
It is a tailor-made semi-submersible rig for mid-water segments on the NCS, but is also applicable in other regions.
The rig concept can easily be converted for work in deep water, high pressure high temperature (HPHT) operations
and arctic regions.
Why cat D?
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. The key to maintaining today’s production level on the NCS
towards 2020 is improved recovery from existing fields and fast and efficient 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.
To meet this challenge, sustainable cost competitiveness, drilling efficiency and sufficient rig capacity are key
factors. Statoil has therefore developed a new mobile offshore drilling unit concept, cat D. This rig will be
customised for year-round production drilling in mid-water depths. The goal is that the new rig will perform
operations 20% more effectively than the conventional rigs. This will reduce field development costs and the rig
fleet will be rejuvenated.
Technical aspects
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 due 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. Statoil’s drilling an well unit has especially high focus on preventing falling objects and ensure well control. This rig category is designed to prevent falling objects, lower well
head fatigue exposure and it has high reliability in well control systems. It is also designed to prevent environmental spills and assure improved working environment.
Commercial aspects
In the market process for cat D, Statoil is asking for offers for a 1) 8-year firm contract period, including
options for 4x3 years, and 2) 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 contractors 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 contractors on Monday 21 February, with planned contract awards in Q3
2011.
To reduce risk and secure yard capacity when the contracts are awarded, Statoil has reserved slots at four
different construction yards. The four yards have the proven construction record Statoil requires to be able to
build the rigs within the expected delivery time:
a.
b.
c.
d.
Daewoo Shipbuilding & Marine Engineering Co. Ltd (DSME) - Korea
Samsung Heavy Industries (SHI) - Korea
Keppel FELS Ltd. - Singapore
Jurong Shipyard Pte. - Singapore
Milestones
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)
Contract award to drilling contractor Delivery of units to well location on NCS
Q1, 2011
Q3, 2011
2nd half of 2014
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www.statoil.com/catD