PeriScope Tool as the Drive to Improve the Geosteering Performance on Odoptu-More Field, Sakhalin

Developing Odoptu-Morye field is inseparably linked to Schlumberger gradually implementing new technologies. Geosteering has been a critical technology for the field development. Odoptu-Morye field is structurally and lithologically a very complicated due to the large number major and sub-seismic faults, high dipping, deposits irregularly, presence of calcite concretions and inconsistent true thickness which not retain laterally. Schlumberger started drilling and measurement on the Odoptu-Morye field in 2003. In 2005 arcVISION, adnVISION and sonicVISION were introduced. During that period pay zone length was up to 100m and all of the wells exited the target zone. In 2007 Schlumberger introduced a well-placement service using ADN density image interpretation. Using this pay zone length was increased to 500m, however exiting the reservoir occurred on every well. Net to gross ratio increased to 67-95%. In 2008 the PeriScope tool was introduced. PeriScope’s directional, deep imaging while drilling was suited to this application because of the high conductivity contrast between the oil bearing reservoir and the roof and base shale. Using the PeriScope tool considerably improved the structural control on the Odoptu-More field and so improves the geosteering performance and achieves a net to gross ratio 100%.