Wellsite Biostratigraphy

Wellsite services summary

• Pick a casing point, coring point, or well TD.
• Confirm/calibrate seismic markers and identify sequence boundaries used for regional correlation.
• Monitor stratigraphy, e.g. “wildcat” wells or in a structurally complex setting.
• “Geo-steer” long-reach horizontal wells.
• Identify the provenance of cavings during borehole instability.

Wellsite services-deep water

Provides fundamental geological data (for minimal cost compared to the overall operation) enabling calibration of seismic while drilling. Can result in significant modification of the well plan, saving rig time and enabling confident subsurface modelling.

• Assists safety critical decisions. Deep water wells are under close scrutiny and real-time biostratigraphy is a means of minimising risk.
• Real-time results obviate the need to wait months for results, or export samples. Wellsite Biostratigraphy from a first well may influence the design of a second well.
• Able to provide dedicated A60 biostrat units, a scientific team from the relevant disciplines, technicians and acid or non-acid palynology.

Wellsite Services-North Sea

Tertiary Assets: PetroStrat have been one of the principal providers of biostratigraphic services to companies targeting Eocene-Paleocene hydrocarbon accumulations across the North Sea since 2001. During this time we have undertaken palynological and micropalaeontological studies on >40 fields and provided real-time wellsite support on over a hundred wells with Tertiary targets.

Cretaceous Assets: Providing high resolution biostratigraphy to Upper and Lower Cretaceous well sections is a major strength. In more argillaceous areas, integration of palynology (non-acid) and micropalaeontology provides a highly refined biostratigraphic zonation that permits recognition of by-pass surfaces within claystone dominated intervals. We have also provided real-time nannopalaeontological & micropalaeontological wellsite support on numerous horizontal Cretaceous well sections (Norway, UK, Denmark & Holland), as well as using both disciplines in tandem to help monitor the Stratigraphy of HP/HT wells requiring casing to be set above the BCU.

Jurassic Assets: Our team of Jurassic palynology & micropalaeontological wellsite experts have vast experience in the Upper, Middle and Lower Jurassic across the UK, Norwegian and Danish sectors of the North Sea. We frequently provide wellsite micro support to HP/HT wells in the Central Graben area and have been involved in numerous reservoir scale studies. Wellsite acid based palynology has been applied to the Jurassic on several non HP/HT wells. Non-acid palynology has also been successfully applied in Upper Jurassic strata.

Non-acid Wellsite palynology

PetroStrat has developed a non-acid palynology processing technique that totally avoids the use of harmful chemicals. This has opened up huge possibilities for the application of this science in real time at wellsite.

• In the relatively shallow Tertiary well sections of the North Sea the technique works extremely well and has on some fields now become the scientific discipline of choice for assisting in the picking of casing points or geo-steering.
• Elsewhere, PetroStrat have been applying the technique at wellsite in Neogene, Palaeogene and Upper Cretaceous strata in West Africa.
• More recently we have been applying non-acid palynology at wellsite on deep water wells targeting Tertiary sand targets at depths in excess of 30,000ft.
• The technique is safe, environmentally friendly and quick to use  (our experienced technicians can provide a palynology slide ready for analysis in 30-40 minutes from receipt of sample). There are few significant logistical issues associated with providing wellsite non-acid palynology, though we usually recommend our team work from a dedicated A60 cabin.
• Non-acid palynology constitutes a significant part of the wellsite cover provided by PetroStrat staff in an average year.