Topaz Development Study

Topaz Development Study – RWE/Vision Oil & Gas (Gas/Condensate, North Sea)

The Topaz field is located in the Southern Gas Basin in the North Sea and straddles UK blocks 49/1 and 49/2, approximately 15km to the South-East of the Tullow Operated Schooner platform. The Topaz field was developed using a single subsea well drilled from a jack-up drilling rig. The well was tied back to the Schooner Platform, via a new pipeline and control umbilical.

Through various phases of project execution from early concept design in 2006 through initial start-up of the field in 2009, our Process Solutions' team of experienced consultants completed the steady state and transient flow assurance analysis on subsea tieback of Topaz gas/condensate field to existing platforms. Both the hydraulic and thermal constraints were evaluated to determine the optimum mode of operation. With sufficient Methanol included in the pipeline to inhibit against hydrates, other key flow assurance issues included liquid surges to the existing platforms already in operation, as well as ensuring the material design temperatures were not exceeded during initial well start-up and restarts. Several start-up scenarios which involved varying the stroke time of the wellhead choke and start-ups over a number of days were investigated to ensure all the constraints were satisfied.