Drilling Without Conductors Piper Field Development

Trendall, T., Occidental Petroleum (Caledonia) Ltd. UK Abstract Occidental discovered the Piper field in the UK of the North Sea, 100 miles east of Wick on block 15/17 in January 1973. After the discovery well, another six wells were drilled to delineate the field. Early on in the appraisal drilling programme, it was decided a single steel platform with twin drilling rigs would effectively develop the field. The size of the platform (one of the largest steel platforms set in the deepest water at the time of setting) caused Occidental to develop a unique concept to help decrease the live loading on the platform construction and development drilling and helping speed initial production start-up. Experience gained from the exploration programme helped Occidental decide that it would be possible to develop Piper, utilizing a redesigned 20 in. string as conductor and doing away with the 30 in. string altogether. This concept was then incorporated into the final design of the platform. PIPER DEVELOPMENT HISTORY PIPER DEVELOPMENT HISTORY The Occidental consortium's interest in the British sector of the North Sea shifted to activate exploration in 1970 following the Ekofish discovery in the Norwegian sector. On the basis of 20,000 miles of seismic data. Occidental placed application for British North Sea blocks with the government in 19712. In March 1972, the government awarded Occidental a petroleum licence for six blocks covering approximately 316,000 acres. Two months after the award. Occidental spudded its first well block 15/11. It was dry. The second well was drilled on 14/19 (Claymore) this was also a failure although shows were encountered. The third well was spudded on 15/17 (Piper). This well had to be abandoned at 750 ft due to weather conditions getting the better of the drill ship used. A new semi-submersible rig. The Ocean Victory, was acquired and this rig spudded 15/17-la in November 1972. This well flowed at a combined rate of about 90,000 bopd and the field was designated Piper field.