North Sea

The North Sea remains one of our core areas. We have particularly strong, state-of-the-art expertise in the following areas:-

(1) Tertiary clastics (Early Paleocene to Pliocene)
PetroStrat has extensive experience of the Tertiary stratigraphy of the Central and Viking Graben areas, having assisted in the development of >20 UKCS fields that produce from Eocene and Paleocene reservoirs, providing wellsite services on over 40 wells (in order to pick casing points and/or monitor reservoir stratigraphy).

Our high resolution approach has enabled subdivision of Eocene sands within the Frigg, Tay, and Skroo depositional systems of the lower Horda Formation (Unit H1), and within the Balder and Sele Formations. In addition, detailed subdivision of the Middle Eocene Horda Formation (Unit H2) at wellsite has permitted accurate positioning of casing points above Tay reservoir sands.

Within the ‘earliest’ Eocene we have demonstrated the existence of sands within units S3 and S2a of the Sele Formation, in addition to the S2B (Cromarty) sands. Differentiation of these Sele sand units (via high resolution biostratigraphy) has proven vital to the development of post Forties reservoir sands in several fields.

Within the Paleocene, PetroStrat have a wealth of experience within the Lista and Maureen Formations of the UK sector and Norway, having completed studies on the Andrew/Heimdal and Maureen/Ty sands in the Viking Graben and on the Andrew/Mey and Maureen sands of the Central Graben area.

PetroStrat has unrivalled experience in the palynostratigraphy of the Forties Sandstone Member, having undertaken intensive studies on over 100 well sections from 12 fields that produce from Forties reservoirs. We have demonstrated that Forties sands vary in age from field to field, and between wells within individual fields. We are actively involved with developmentdrilling on several fields, providing non-acidic wellsite palynological services to assist with picking casing points and geosteering highly deviated and horizontal wells.

(2) Chalk (Late Cretaceous and Early Paleocene)
We have vast experience in chalk sections, including wellsite monitoring or “biosteering” of many long-reach development wells in the UK, Danish and Dutch sectors (and the giant Norwegian fields).

(3) Cromer Knoll Group (Early Cretaceous)
Again, we have enormous experience in this interval which was the focus of Dave Rutledge’s Ph.D. in nannopalaeontology. PetroStrat has provided wellsite services in the UK, Norwegian, Danish and Dutch sectors in order to assist casing and coring picks within the Cromer Knoll Group.

(4) Jurassic
We have strong expertise in North Sea Jurassic micropalaeontology/ stratigraphy and particular expertise in radiolaria following John Gregory’s Ph.D. research. PetroStrat has considerable experience in integration and re-interpretation of large regional datasets (biostratigraphy, lithostratigraphy and sequence stratigraphic correlations) within the Moray Firth, Central and Viking Grabens. Micropalaeontology has proven invaluable during wellsite monitoring of HP/HT wells where palynology is not viable (due to steep thermal maturation gradients).