Radial jet drilling was applied recently on an experimental basis in Oil India Limited (OIL) to retrieve production from some locked up potential in reservoirs with low permeability and near well bore formation damage, through enhanced exposure, with an ultimate objective of maximizing the total long-term hydrocarbon recovery from the reservoirs.
Radial drilling is a Frac-Less well stimulation technique used worldwide by Exploration and Production (E&P) companies to enhance production from depleted/damaged reservoirs. This well intervention technique involves milling of a 22 mm hole in the production casing of the mother well and then creating holes of approximately 50 mm OD with a maximum length of 100 m in the reservoir by removal of material from the formation using high hydraulic jetting pressure. Radial drilling is a proven technique to bypass the damage near wellbore zones.
The Paper depicts the successful completion of radial drilling operations in Four (4) nos. of pilot wells (3 oil well & 1 gas well) in four (4) different reservoirs of Oil India Limited, a post job production analysis and technical learning's from the Project.
The depth of the target zones varied from 2407 m to a record depth of around 3226 m (deepest well in India where Radial Drilling has been implemented). The first pilot well was completed with 3 laterals (length 29.5 m-100 m) with 900 phasing. The second well had 5 laterals (length 30 m-100 m) with 900 phasing in two different reservoir depths. The third well was completed with 4 laterals (length 97 m- 100 m) while the fourth pilot well was successfully completed with 8 laterals of length 50 m each at two different reservoir depths.
Post radial drilling production performance of the wells have been analysed and covered in the Paper. Significant increase in production was observed in the first three (3) wells, however no improvement in production could be achieved from the fourth pilot which was a gas well.
Mechanically, the application of this technology has been a complete success with all laterals drilled in the selected mother wells.
The technical experience and knowledge gathered from the pilot radial drilling campaign certainly presents an opportunity to unlock untapped potential for incremental production for future similar wellbore and reservoir conditions in Oil India Limited (OIL) as well as in other Exploration and Production (E&P) operators worldwide.