已发表: 03/27/2013
已发表: 03/27/2013
An operator working in Western Siberia's Kogalymskoe field was drilling 8 1/2-in S-shaped directional boreholes through an interbedded sand and claystone Cretaceous formation to access the Jurassic reservoir. While the section has a relatively low unconfined compressive strength (UCS) of 3,000 to 10,000 psi, efficiently drilling long intervals in this formation at a high ROP has proven difficult when using locally produced PDC bits. Generally, the motor-driven PDC bits being used were drilling sections to TD in 8 days after multiple runs at average ROPs below 36 m/h. The operator was seeking a bit for the application that could drill at a greater average ROP to reduce the number of rig days.
For the operator's application, Smith Bits recommended the 8 1/2/2-in Viking Bits ViM613 matrix-body PDC bit. Specifically designed for Russian drilling operations, PDC bits from Viking Bits have a cost-effective matrix or steel body with increased blade height for efficient cuttings evacuation and increased ROP. Designed using IDEAS integrated drillbit design platform, the bit's advanced cutting structure produces smooth torque response in the curve while its depth-of-cut reduces cutter loading, minimizing vibration during transitional drilling. The Viking bits were also fitted with optional Lo-Vibe depth of cut control inserts to increase protection from impact damage in the bit's gauge and shoulder areas. The result is a highly durable PDC bit with excellent directional responsiveness that is aggressive enough to deliver higher ROP.
The Viking Bits 8 1/2-in PDC drill bits used for the three wells in the Kogalymskoe field directionally drilled a total of 7,043 m at an average ROP of 42.4 m/h.
Run on a PDM, the bits displayed excellent directional control with no vibration or steering problems and drilled all three sections in single runs. When compared with the PDC bits used in offset wells, the Viking Bits ViM613 matrix-body PDC bits increased average meters drilled by 40.7% and ROP by 19.8%, saving the operator at total of 6 rig days on three wells.
Challenge: Drill three 8 1/2-in S-shaped well sections of at least 2,000 m from shoe to TD in single runs through an interbedded sand and claystone formation.
Solution: Run the Viking Bits 8 1/2-in ViM613 matrix-body PDC bit on a positive displacement motor (PDM) for all sections.
Results: Drilled three 8 1/2-in S-shaped well sections totaling 7,043 m at an average ROP of 42.4 m/h, which when compared with bit performances in offset wells represents a 40.7% increase in average meters drilled, a 19.8% increase in ROP, and a saving of 6 rig days on the three wells.
