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Introduction

In their sustainability strategy reports, the UK Offshore Operators Association (UKOOA) has recognised the UK government’s drive to reduce emissions as committed to under the Kyoto Protocol. Details of emissions by the oil and gas industry are published in UKOOA environment reports and more recently in their sustainability strategies.

Within the UK offshore operational area, flaring accounts for some 20%1 of CO₂ emissions from the offshore oil production industry with 71% from power generation. Whilst the industry is seeking power efficiency, flaring remains the most visible area for reduction in emissions. Industry efforts within the UK included a UK voluntary flare consent pilot scheme where operators agreed targets on average 10% below flare consent levels. In addition, voluntary entry by some operators into the UK Emissions Trading Scheme (ETS) that formally starts in April 2006 should help focus the attention on flaring.

These moves, in practice, are hampered by the cost of modifications offshore and, in general, although many operators will allow capital expenditure/expense (CAPEX) investment on reduced rate of return targets for environmental projects, it is still required that all such projects offer a return on investment (ROI). It is therefore essential that if real environmental benefit is to be won, real cost saving must also be found.

Flare system maintenance is coincidentally very expensive. Unexpected flare failure is serious. The flare system cannot be maintained when in service and on most systems will require a complete production shutdown to change out flare components, thus costing a minimum of three or four days loss in production, or during a planned shutdown the flare maintenance is often on the critical path. Thus it can be seen that if improvements in flare system maintenance can be achieved, the industry’s desired aim of CO₂ reduction through reduced flaring may be paid for by maintenance improvement. This is the target to be achieved. In today’s technology there are complete flare systems available that approach zero flare solutions. These systems cannot remove the basic need for an emergency flare as a final safety device, but can and do offer real cost and environmental benefits at extinguishing or managing the flare in daily use.

UK Flaring versus Norwegian Flaring

In the UK, flaring has typically averaged at two million tonnes of gas per year from about 150 production facilities with a slight reduction showing in recent years (see Figure 1). According to UKOOA (2)

“The industry’s CO₂ emissions represent some 4.5% of overall UK emissions (2001 data). 71% of offshore CO₂ emissions are from gas consumed in turbines, with a further 20% from flaring”.

Figures accumulated for Norway in the same period of 2001 show offshore petroleum operations accounting for 28% of the country’s total CO₂ production. Clearly, the Norwegian petroleum industry is a far more significant proportion of the national gross domestic product (GDP) than in the UK. To some extent, this explains the emphasis placed in Norway on their efforts to reduce flaring. In Norway the government chose to introduce a CO₂ tax in the 1980s, focusing attention greatly on excessive flaring.

This focus on flaring was demonstrated when the Gullfaks partners, led by Statoil, developed flare gas recovery systems and implemented them on the offshore facility. Along with the flare gas recovery system was a new type of ignition system based on a pellet fired to hit a striker plate and shower the whole flare deck in sparks. This was required to improve the reliability of the flare ignition systems to match the new normally ‘not lit’ operational philosophy and allow the flare pilots to also be removed, further reducing CO₂ emissions. The net result on the Gullfaks project was that CO₂ emissions attributed to flaring was cut by half.

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