SS: Offshore Integrity: The Life-Cycle Management of Subsea Facilities
Authors: Strutt John E. , Baker Jerry 
Published: July 2010

This paper presents the case for an integrated systems approach to subsea reliability and integrity management. The paper starts by reflecting on the historical development of reliability and integrity management and how the differences between integrity and reliability appear to be related primarily to historical development and approach, rather than to fundamental differences in philosophy. Using the example of a typical subsea system and drawing on the recently-published Guidelines for the management of integrity of subsea facilities[1] and Recommended Practice for Subsea Production System Reliability and Technical Risk Management[2], the authors explain how both reliability and integrity as management systems may be combined to optimize life-cycle management. The paper discusses what should be addressed at the design stage to ensure successful life-cycle operations, and what should be addressed in operations to support the design process. Attention will be paid to the subsea production control system and the chemical injection system and the role of reliability analysis and data management. The authors recommend that the industry consider the development of a single recommended practice that addresses both reliability and integrity management throughout the life-cycle. While the discussion is focused primarily on subsea, the issue has wider relevance to the upstream sector of the oil and gas industry.

Introduction

It is well recognized, especially for deep water operations, or for operations in remote locations with poorly-developed infrastructure, that the cost to restore or repair failed subsea hardware can be substantial and can adversely impact on the economic performance of a subsea development. Any failures which stop or reduce production during operation are financially harmful. Failures which cause loss of containment may also have safety or environmental consequences with even greater financial impact. All failures are bad for business, but particularly damaging are early life failures, which have the greatest impact on discounted cash flow and the greatest visibility and hence impact on company reputation.

Subsea installations, like all hydrocarbon production systems, are susceptible to equipment failure and, over time, Operators have developed a range of management systems and strategies to prevent accidents and losses including; Quality, Integrity, Value, Safety and Environmental management etc. These have been and continue to be the central tenets of the industry. Although there are strong dependencies between each of these, to a large extent Operators have generally addressed each separately. For example many operators have an integrity management system, as well as a quality management system and an HSE management system. Interestingly, until recently the inclusion of reliability engineering and its management has not been included as a specific management practice, despite its direct relevance to failure prevention. However, reliability management is now gaining greater acceptance as a key practice in subsea field development projects and this is leading the authors of this paper to question how reliability management should relate to existing management systems. It is quite clear, for example, that Quality and Reliability are closely related disciplines and have similar objectives as do Reliability and Integrity.

In this paper the authors make the case for creating a greater focus on reliability and its integration with integrity management. Our opinions are derived from practical experiences in the application of reliability and integrity management, but the motive is greater technical effectiveness and improved efficiency. Two publications have influenced this thinking; the Energy Institute Guidelines for the management of integrity of subsea facilities[1] and the American Petroleum Institute recommended practice API RP 17N; Recommended Practice for Subsea Production System Reliability and Technical Risk Management[2]. There would be a benefit to having a single recommended practice to bring together these two strands because they are so clearly interlinked.