Grane is one of Hydro's major producing platforms in the North Sea. The field was discovered in 1991 and first oil flowed on deck on September 23, 2003. The field is located 100 nautical miles west of Stavanger, Norway. Current production, as of January 2006, is 230,000 barrels of oil per day (BOPD).
This document describes the four major areas in the project, which contributed to keeping budgets and drillingtime plans.
Figure 1. Grane (available in fullpaper)
The Grane drilling module was built at Aker Stord Shipyard in western Norway in 2003.
Odfjell Drilling Management (ODM) was awarded the drilling contract in April 2001 and got involved early in the project with key personnel. The drilling unit was designed under Norsok Class 1 rig specifications, with addidional Hydro Drilling requirements.
The platform is a conventional type - a fixed PDP with the drilling unit positioned at the aft end.
The following key requirements were built into the design, concept studies and project plan:
Stand-alone drilling unit with high focus on working conditions and safety
Highest environmental standard with no discharges into the sea
Highest possible degree of remote-controlled operation based on proven equipment and with minimum exposure of personnel in hazardeous areas
State-of-the-art control and communication systems
Cost effective and compact unit with normal well capacities up to 8,000 meters
Optimal weight control and layout
Optimal use of materials such as aluminium and stainless steel in order to control maintenance costs over time
High operational regularity of all drilling systems.
Main consumers to be AC-driven motors
Simultaneous drilling and wire line/coil-tubing operations
Early involvement of contractor personnel in design phase
High focus on completing the testing and commissioning activities onshore for all systems
Complete live-drilling test onshore prior to loading out the module
Training of operational personnel prior to and during offshore hook-up phase
Involvement of equipment suppliers in commissioning and early start up
Tie back of 12 pre-drilled wells during main hookup/ commissioning phase (this decision proved vital for early production build up)
The main drilling contractor got involved at an early stage of the design and building of the drilling module. During the building period, a total of 22 persons from ODM were involved. Some were integrated in the contractor team while others became part of the Hydro site team.
30-year lifetime design
Fingerboard capacity, 8000 meters
Hoisting capacity, 4450 kN
Zero discharge to sea philosophy
40 well slots
27 production wells planned with gas lift
8 gas, water and cuttings-slurry injection wells planned