Biosteering - A biostratigraphic application to horizontal drilling in the Eldfisk field, Norwegian North Sea
- Phillips Petroleum Company, Bartlesville, OK (United States)
- Phillips Petroleum Company, Stavanger (Norway)
- Network Stratigraphic Consulting Limited, Hertfordshire (United Kingdom); and others
Biosteering is an application of biostratigraphy that monitors drilling through and along the reservoir interval (horizontal section). Traditionally, biostratigraphy has provided information regarding the age, zonation, and paleoenvironment at the time of sediment deposition. This data can be used to identify and correlate a particular stratigraphic level. Wellsite biostratigraphic information can rapidly identify stratigraphic horizons. This information can then assist in steering the well through the reservoir, and predict anticipated sections ahead of the drill-bit. The primary target reservoir in Eldfisk Field is the upper part of the Tor Formation (TA layer). Prior to development drilling, a detailed biostratigraphic framework was established which provided sufficient stratigraphic resolution to identify the reservoir layers. This framework utilized micropaleontological and nannoplankton index species, reworked elements, changes in relative abundance, and assemblage associations. The age of the Tor to Ekofisk Formations ranges from late Campanian to early Paleocene Danian. Nine combined zones are recognized in the Tor to Ekofisk Formations. A number of allochthonous units are suggested in the Ekofisk Formation which represent the facies of reworking. The lowermost layer is generally missing. A total of five horizontal wells have been successfully drilled in the Eldfisk Field through January 1995. Although the original objective was to continuously remain in the upper part of the Tor Formation, local pinchouts and thinning hamper this effort in some wells. However, this biosteering technique is critical to drilling horizontal wells, and yet represents a minute portion of the total expenditure.
- OSTI ID:
- 159956
- Report Number(s):
- CONF-951094-; ISSN 0149-1423; TRN: 95:006835-0054
- Journal Information:
- AAPG Bulletin, Vol. 79, Issue 9; Conference: Meeting of the Mid-Continent Section of the American Association of Petroleum Geologists: technology transfer - crossroads to the future, Tulsa, OK (United States), 8-10 Oct 1995; Other Information: PBD: Sep 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
An integrated approach to the development of the Alba Field in the UK North Sea
Foraminiferal biostratigraphy and paleoecology of Wilcox group (Paleocene-Eocene), central Louisiana