Pilot Hole Bit 8.5*9.5 Inch Bi-Center Drill Bit Of API Spec
1. Specification
A variety of Bi-Center bits are available from us in both Steel and Matrix body types.
The products from Bi-Center include the following performance-enhancing features:
• Directionally responsive;
• Force-balanced cutting structure;
• CFD enhanced hydraulics arrangement.
Our Bi-Center bits can be produced with or without the Feature depending on the application needs and client preferences. The size range available is 3-7/8" to 17-1/2" with a blade count that is application-specific.
BI CENTER SIZE | STABILIZER SIZE | % DRILL SIZE |
17” X 20” | 14.5 | 72 |
14.5” X 17.5” | 13 | 74 |
12.25” X 14.75” | 11.5 | 78 |
12.25” X 13.5” | 10.5 | 78 |
10.625” X 11.5” | 9.25 | 80 |
10.625” X 12.25” | 10 | 82 |
8.5” X 9.875” | 8.25 | 84 |
6.5” X 7.5” | 6.5 | 86 |
6” X 7” | 6 | 86 |
2. Specification
BIT SPECIFICATIONS | ||
Body Type | Steel | |
Main Cutter Size | 13mm | |
Nozzle: | 5N50 | |
Bit Connection | 2-3/8 Reg API Pin | |
Make up Length | 2inch | |
OPERATION PARAMETERS | ||
Rotation Speed | 65-200 rotary | |
Weight on Bit | 5-25 klbs | |
Flow Rate | 440-700 gpm | |
Make Up Torque | 15.5-18.5 klbs -ft |
3. Configuration
The three sizes of the bi-centered bit are the pilot bit diameter, the drilled hole diameter, and the pass-through or casing transit diameter. The bit may shift to one side of the hole when it is lowered or raised through the casing, so the pass-through diameter is smaller than the drilled diameter.
The pilot bit keeps the string in the middle as the offset reamer blades are pressed up against the side of the borehole.
A stabilizer that would help center the drilling motion cannot be placed directly above the bi-center bit because it must be allowed to move through the casing. The bit can only be partially stabilized as a result.
This pass-through also limits the diameter of the downhole motor used behind the bit. The new invention of dual mud motors, which double the motors' output, has increased the range of bi-center drilling in high-angle wells.
4. Tripping VS Drilling
5.Features and Benifits
• Force-balanced cutting structure – This significantly reduces the likelihood of bit-induced downhole dynamics events, even in demanding applications.
• CFD enhanced hydraulics designs: Optimised nozzle positions and orientation guarantee efficient cutter cleaning and cooling, prevent cuttings from being recycled, and reduce the risk of balling.
• A wide selection of top-notch PDC cutters that can be altered to suit the requirements of any specific application.
• All Bi-Center bits are designed to efficiently drill out casing shoes.
• Directionally responsive: All Bi-Center bit designs were made with directionality in mind, and they can function effectively with directional motors that have bends of up to 2.
6. Advantages Of Bicenter
These enhancements and adjustments reduced the lateral forces acting on the reamer, decreased the tendency of the pilot bit to spiral, and prevented the reamer from boring too deeply into the borehole wall. The bi-center bit now successfully drills deviated holes by harnessing and managing this drive to dig in instances where borehole reaming is required. Bi-center bits also prevent underreaming and reduce drillstring trips, among other benefits.
• Increase the casing through the areas of the bent holes.
• As soon as you can, dissolve any pieces with swelling shale or creeping salt.
• Enlarge the window casing openings.
• Lessen directional restrictions in small-diameter boreholes.
• Avoid using unbalanced formations for second runs.