An integral part of modern horizontal drilling operations

The biosteering technique is now widely recognised as an integral part of modern horizontal drilling operations. Biosteering involves provision of real-time stratigraphic data at the wellsite. Used in conjunction with downhole logging data, it provides a high degree of control and enables correction, or 'steering' of the well trajectory to maintain an optimum level within the reservoir.

Pioneering development

The technique of biosteering was first developed by Robertson stratigraphers for the chalk fields of the Danish sector of the North Sea, and has subsequently been applied to horizontal/subhorizontal drillings throughout the North Sea (in both carbonate and clastic reservoirs) and the Middle East (carbonate reservoirs). All three biostratigraphic disciplines have proved valuable for biosteering in various reservoir facies.

Major benefits

Biosteering assists in the positioning of the well at the optimum reservoir level.

It also enables recognition of (and correction for) faulting and/or unanticipated changes in stratal dip.

It may enable re-interpretation of seismic sections along wellpath.

By using the technique in conjunction with logging while drilling (LWD), even greater refinement can be achieved. One significant advantage of wellsite biosteering is its ability to indicate the direction and size of throw on a fault, which is all important when correcting the well trajectory to re-enter the target zone.

Pilot studies

For maximum effectiveness, an initial, quantitative office-based pilot study must be undertaken in order to develop a high resolution local biostratigraphic scheme for a relatively short stratigraphic interval, including the target horizon. Such pilot studies are ideally conducted using closely spaced core material from nearby wells, but, given prior experience in a field, they may be conducted on a pilot-hole drilled across the target zone prior to pulling back and drilling the horizontal section. Several biostratigraphic disciplines may be employed in the pilot study, to determine which would be most useful at wellsite.

World records

Robertson has extensive experience of biosteering in the North Sea, Oman, Qatar, Saudi Arabia and the UAE. Our biosteering services have assisted in the drilling of several world record horizontal distances.


GeoConsulting - Biostratigraphy


Wellsite and routine stratigraphic services (micropalaeontology, palynology and nannofossils), high resolution reservoir stratigraphy, sequence stratigraphic evaluation and more.

GeoConsulting - Sequence Stratigraphy

Sequence Stratigraphy

Applying the principles of sequence stratigraphy to many sedimentary basins worldwide, including identification of regional sequence boundaries and integration of quantitative biodata.

GeoConsulting - Wellsite Biostratigraphy

Wellsite Biostratigraphy

Monitoring the stratigraphic progress of wells, assisting in setting casing points and monitoring coring programmes.