Abstract
This paper will describe results of the application of new drilling technology on the well cycle time and production results in the Verkhnechonskoye (VC) Field - one of the largest fields in Eastern Siberia (estimated >200 million tons of oil reserves) with TNK-BP & RosNeft as VCNG's main (company operator) stock holders.
The Drilling & Production environment in the VC field is very challenging, drilling encounters a range of issues from, low ROP in hard dolomites, risk of stuck pipe in unstable shales, high stick'n’slips, to unpredictable BHA behavior in hard gravalite zones, these challenges are compounded by the complex geology of this hetrogenous field. To meet the FDP schedule of 500+ horizontal wells (during 2007-2021) and the production targets (up to 10 million tons of oil per year) it was necessary to significantly improve the well construction time and maximize the net to gross pay ratio of the horizontal section.
VCNG drilling department partnered with Schlumberger and over a period of 24 months completely redesigned the drilling programs and data acquisition methods. The subsurface team developed a methodology to significantly improve drilling efficiency using Schlumberger Rotary Steerable Systems. While the net to gross of the horizontal sections was improved by utilizing high tech Logging While Drilling tools and Geosteering the well to overcome the geological uncertainties.
The initial well cycle for a development well completed using positive displacement motors and standard directional techniques averaged 63 days. The horizontal section of the well was exhibiting a net length to gross reservoir exposure of approximately 30%. By July 2010 the well construction cycle was reduced to 22.3 days including an addition 100+ m of lateral section and the net to gross was 70+% with corresponding higher production.
These latest drilling benchmarks and lessons learnt from one of the first major development projects in the heart of Eastern Siberia will be reviewed in this paper. Information on the basis of well design, the theoretical drilling limit, and the application of drilling technology coupled with information on work processes and best practice will be pertinent to other Eastern Siberia development projects.
