An increasing number of wells are being completed subsea. Increasingly these developments are further away from existing infrastructure, in deeper water or exposed to hostile environments. All of these features mean that production must become increasingly reliable. In addition, in such a risk averse industry(especially when considering the challenges above), the rate of innovation (or speed to market) can be greatly hampered, regardless of potential economic benefit. This is mainly due to the current difficulty in demonstrating the reliability of new technologies (such as HIPPS, MFMs, Subsea pumping, Subsea Processing and so on) because of a lack of field experience. The Implication of slower innovation and less understanding of the risks may lead to a slower path to the improvement of both performance and reliability

The achievement of reliability requires an understanding of what causes unreliability and how unreliability and its associated risks can be managed or prevented

This paper will discuss current industry method of measuring, record and understanding the causes of unreliability with particular attention of using averaging statistics such as Mean Time Between Failures (MTBF). The paper will present methods available to increase the understanding of reliability, including understanding the causes and frequency of failure, through data acquired from filed experience and accelerated testing. The implications of these methods on the development of novel technologies of assured reliability will be explored.


The North Sea saw the first the first subsea architecture development in the early to mid-sevents Notable success included, Ekosfisk, shell UMC(underwater Manifold Centre) and the Hamilton Argyll field. The shell UMC is still operating today, while the Argyll field is about to be re-opened and revised after being abandoned some tens years ago

Subsea field development are becoming increasingly challenging. The challenges include deepwater, HPHT, aggressive environment and ?marginal? economics. It is increasingly important to get ‘get it right’. This means higher reliability and technology development. It is essential that we manage our future by managing the introduction of new technologies.

Today#x0027;s global challenges tend to be focused on ultra deepwater developments (>1500m), but mature provinces also have an important part to play, both in terms of fossil fuel but also as a platform for renewable development.

(The Figures is available in full paper) Deepwater developments are characterised by high infrastructure and intervention costs, which mean that high productivity levels need to be ensured to recover the exploitation costs. Mature provinces are characterised by marginal reserves where the development relies on minimum CAPEX through minimum infrastructure, and the profitability of the field can be extremely vulnerable to operating upsets and downtime. For technically demanding fields, such as HPHT, the development relies on potentially difficult trade-offs between CAPEX and operability, which can also mean the profitability of the field is vulnerable to operating upsets and downtime. The challenge then, is very clearly high reliability.

There is a perception that reliability can be improved, this is discussed more in the following section. A number of high profile early life failures have adversely affected the perception of the subsea business.

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