Clair Phase 1: The Evolving Development of a Complex Fractured Field
- Mark Webster (BP Exploration Operating Company Ltd)
- Document ID
- Society of Petroleum Engineers
- Abu Dhabi International Petroleum Exhibition & Conference, 12-15 November, Abu Dhabi, UAE
- Publication Date
- Document Type
- Conference Paper
- 2018. Society of Petroleum Engineers
- Fractured reservoirs, West of Shetland, Waterflood development, Old Red Sandstone
- 4 in the last 30 days
- 153 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 9.50|
|SPE Non-Member Price:||USD 28.00|
The Clair field is the largest discovered oilfield on the UK continental shelf (UKCS) but has high reservoir uncertainty associated with a complex natural fracture network. The field area covers over 200 sq km with an estimated STOIIP of 7 billion barrels. The scale and complexity of the reservoir has led to a phased multi-platform development.
Phase 1 started production in 2005 with 20 wells drilled prior to an extended drill break. Five new wells (A21 to A25) were drilled and brought online during 2016/17 which increased platform production by c.70%. The new wells incorporated historic lessons to mitigate the risk of wellbore instability in the overburden and be robust to the dynamic uncertainties of the fractured reservoir. Many of the well outcomes and risk events were predicted and mitigated effectively, however the new wells still provided some surprises.
This paper presents a summary of the lessons from the historic Clair development wells which underpinned the recent drilling campaign and additional field understanding provided by the new well results. New insights include a narrower overburden drilling window and zonal isolation challenges within the reservoir.
|File Size||1 MB||Number of Pages||13|
Barr, D., Savory, K., Fowler, S., Arman, K. & McGarrity, J. P. 2007. Pre-development fracture modelling in the Clair Field, West of Shetland. In: Lonergan, L., Jolly, R. J., Sanderson, D. J. & Rawnsley, K. (eds) Fractured Reservoirs. Geological Society, London, Special Publications, 270, 199–219.
Coney, D., Fyfe, T. B., Retail, P. & Smith, P. J. 1993. Clair appraisal: benefits of a co-operative approach. In: Parker, J. R. (ed.) Petroleum Geology of Northwest Europe: Proceedings of the 4th Conference. Geological Society, London, 1409–1420. DOI: 11.1144/0041409.
Davies, D. M. D., Mannaerts, H., McGarrity, J., Ibram, M., McKenzie, C., Campbell, S., Alexander, G., Lozanano, A., Kemmegal, J., Barkved, O., 2011. High-Density OBC-A Step Change in Reservoir Imaging-A BP North Sea View. Society of Petroleum Engineers. DOI: 10.2118/146144-MS
Nichols, G. J. 2005. Sedimentary evolution of the Lower Clair Group, Devonian, West of Shetland: climate and sediment supply controls on fluvial, aeolian and lacustrine deposition. In: Doré, A. G. & Vining, B. A. (eds) Petroleum Geology: Northwest Europe and Global Perspectives: Proceedings of the 6th Petroleum Geology Conference. Geological Society, London, 957–967. DOI: 10.1144/0060957
Nelson, R. A., 1981. An Approach to Evaluating Fractured Reservoirs, Journal of Petroleum Technology, 34, 09; 2167–2170, DOI: 10.2118/10331-PA
Witt, A. J., Fowler, S. R., Kjelstadli, R. M., Draper, L. F., Barr, D. B. & McGarrity, J. P. 2008. Managing the start-up of a fractured oil reservoir: development of the Clair field, West of Shetland. In: Vining, B. A. & Pickering, S. C. (eds) Petroleum geology: From Mature Basins to New Frontiers – Proceedings of the 7th Petroleum Geology Conference. Geological Society, London, 299–313. DOI: 10.1144/0070299.