There have been a number of dry tree developments over the past 5 years where new build drilling facilities have been designed and constructed as an integral part of the overall platform.
Each project has approached the specification, design and integration of the rig using different contractual arrangements. For example, the stage at which the drilling design team, the equipment suppliers, the fabricator and the drilling contractor become involved has varied widely between projects.
The degree of success of these integrated drilling facilities projects, both in terms of the rig being delivered on time and within budget, and also then operating as intended, has at best been variable.
The paper will describe the approach taken for the Benguela Belize project that started detailed design in February 2003. The fully mechanised 4,600hp rig is currently being commissioned in Houston and will sail away in February 2005 following the completion of onshore commissioning and acceptance.
The paper will cover how the project has been set up, including the development of an appropriate safety culture, the detailed design, fabrication, onshore commissioning and the training of the senior drill crew members prior to sail away.
The lessons learned from designing an appropriately specified rig and integrating the rig systems with the topsides contractor throughout the design will be discussed.
Introduction
The Benguela Belize field is in Block 14 offshore Angola. It was discovered in 1998 and will be developed with a central hub platform that is currently under construction. The facilities will be installed during Q1/2 2005.
The 33,600t dry weight topsides will be set on a compliant tower in 1,280ft of water. The Front End Engineering Design (FEED) was completed during 2000 / 2001. Given the large number well slots, forty, of which six wells have been predrilled for subsequent tieback, an initial drilling programme of five years, and the likely need to sidetrack or workover wells throughout the field life, a permanently installed platform rig was justified. In line with project safety expectations and performance requirements a mechanised rig was specified.
One of the beneficial outcomes from the FEED process was the identification of a clear contracting strategy for the project. For the drilling facilities two separate contracts were used, an Engineering Procurement, Construction (EPC) contract and an Operations and Maintenance contract. These were competively bid during 2002 and awarded in February 2003. The changeover between the two will take place once the rig is commissioned and accepted offshore. The project schedule is provided in Figure 1.
EPC Strategy
The pre-qualification package sent out during Q3 2001 provided an outline of the schedule, scope of work and the outline rig requirements.The rig was to be mechanised and integrated into a large platform facility.The requirement for an incident and injury free execution of the work would be a prime objective of the project.This project was to be a lump sum EPC contract, and hence the risk of not tightening the specification in time for the Invitation to Bid (ITB) response was clearly with the contractor.The responsibility for the final equipment selection was clear. The functional specifications would be provided in the ITB and from these it was expected that the contractor would select their equipment, providing a basis for their selection and a clearly documented project execution plan.
