Opportunities for Increased Safety and Operability of A Deep-water Semi-submersible
Through the Application of HFE
Authors: Sworn Andrew , Stirling James 
Published: October 2008

Abstract
Diamond Offshore Drilling Inc. (Diamond Offshore) and BP Exploration Inc. (BP) are converting the 'Polyconfidence' accommodation semi-submersible into a deep water drilling semi-submersible, the 'Ocean Confidence', suitable for 7500 feet water depth and harsh environments. In order to significantly improve the safety and reliability of the vessel when operating, the conversion project is including Human Factors Engineering (HFE) practices during the detail design and construction.
HFE has a long history in many high profile industries such as space travel, aerospace, nuclear power, and the military, but this vast wealth of knowledge has had limited application in the offshore drilling industry. This omission has been urgently challenged as long ago as 1990 by the HFE profession, ref. 1. The Ocean Confidence conversion is a significant step for Diamond Offshore and BP to increase the benefits of HFE practices in the design and operation of an offshore drilling vessel.
This paper will assist rig operators and marine construction companies who are interested in building or upgrading vessels for offshore drilling operations and for operational teams from oil companies and drilling companies who are targeting improved offshore safety and operational performance.
This paper will describe the strategy for implementation of HFE on the project, how the project organisation adapted to implement HFE, the interfaces with designers, constructors and rig personnel and the methods used to verify and measure the effective impact of HFE on the conversion and operation of the vessel.
This paper will show how Diamond Offshore and BP Exploration and have successfully incorporated HFE in the design of the rig to date, areas where there are opportunities for further improvement and the forward program up to the completion of the project in the second half of 1999.

Introduction
The Ocean Confidence drilling rig was conceived in 1997 as a deep water drilling and well completion semi-submersible suitable for 7500 feet water depth and harsh environments, such as the UK and Norwegian North Sea. The'Polyconfidence' accommodation vessel was selected as the vessel most suitable for conversion. The main specifications for the conversion are shown in table 1.
Diamond Offshore has formed an integrated project team for the Ocean Confidence conversion. The drilling company, oil company, major equipment vendors, shipyard and rig crew have been fully involved in the project execution from an early stage. This project strategy is a new way for these companies to work together and has presented many opportunities to work more effectively.
The safety strategy adopted for the Ocean Confidence design was considerably influenced by one of the major project goals :- 'to produce a vessel with world-wide operational capability, particularly the European Sector, the US Gulf Coast and West Africa'. This required that the vessel not only had to be designed to be safe and reliable, but this safety and reliability needed to be demonstrated and documented using safety evaluation and risk assessment techniques.