Fiscal Flow Measurement in the Millennium: An Operators View

The Theddlethorpe Gas Terminal (TGT) is situated on the Lincolnshire coast in the east of England. It is a 2 billion standard cubic feet per day plant (2Bscfld) and has the capacity to process approximately 20% of the UK daily gas supply. The terminal began life in 1972 with the deveJopment of the Vikll1g Gas Field, and has continued to be developed and expanded as further offshore fields have come into production. A brief chronology follows: (A glossary of terms is provided at the end of the paper) • 1972 Viking Field and Gas Terminal (VGT) developed • 1984 Victor Field comes on Stream commingled with Viking • 1988 LOGGS and LGT lDstalled for V Fields • 1989 Audrey (Phillips) comes through LOGGS and LGT • 1991 Anglia (Ranger) added to LOGGS system • 1992 Pickerill (Arco) come~ through new PGT • 1993 Caister (Total), Murdoch (Conoco) and Ann (Philhps) Fields deveJoped. TerminaJ is integrated to allow for blending. T ACA goes hve. • 1995 Jupiter comes on stream through LOGGS • 1996 Schooner (Shell) is introduced through CMS • J 998 Phoenix (Viking Extensions) Ln terms of both physicaJ infrastructure and corrunercial activity, the TGT area represents significant challenge and complexity. Along with the increase in field development and gas productJon, there have been significant changes to the commercial environment: As it was • Monopoly Buyer • Managed Market • DepJetion Contracts • Stability of Long Term Contracts • Known Price • Unknown Demand < VK Only As it is • Multiple Buyers • Multiple Sales Contract Types • Gas-to Gas Competition • Lower Consumer Prices • Lower Beach Prices • Continental Opportunities from 1998 • Volatility in beach price • Buyers keen to re-negotiate The offshore infrastructure compnses some 100 producing wells, silL!ated on over 30 platforms and 5 subsea manifolds. (See Figure I). The offshore production is commingled at three manned gathering centres, where separation, metering and compression wke~ place. The fluids are then recombined for transport to TGT vIa 4 trunk lines. At the terminal. the flUIds are agall1 separated. with condensate be; ng recovered and senr via a dedicated pipeline to the Conoco refinery on Humberside and the dry gas redelivered across three delivery points two for Transco and one to f(inetica. "In the day" activity is managed from TGT, with overall commercial activity and management being carried out in Aberdeen.