Kembali
In the oil and gas industry, a drill bit is a tool designed to produce a generally cylindrical hole (wellbore) in the earth’s crust by the rotary drilling method for the discovery and extraction of hydrocarbon such as crude oil and natural gas. This type of tool is alternately referred to as a rock bit, or simply a bit. The hole diameter produced by drill bits is quite small, from about 3.5 inches (8.9 cm) to 30 inches (76 cm), compared to the depth of the hole, which can range from 1,000 feet (300 m) to more than 30,000 feet (9,100 m). Subsurface formations are broken apart mechanically by cutting elements of the bit by scraping, grinding or localized compressive fracturing. The cuttings produced by the bit are most typically removed from the wellbore and continuously returned to the surface by drilling mud circulation.
A. Roller Cone Bit
Type of roller cone bit is indicated by diameter code, series code, IADC classification code and optional feature code.
For example: 8 1/2MD517X
- 8 ½ is bit diameter, which is 8.5 inches
- MD is series code, indicating the bit is a high speed motor bit
- 517 is classification code or IADC code
- X is optional feature code, indicating the main cutters are convex crested wedge
Type of Roller Cone Bit
MD High Speed Motor Bit
The bit working condition in directional and horizontal drilling applications is quite different than in vertical drilling. The MD series motor bit features high RPM, better gage protection and stability, higher reliability, excellent hydraulic effect and longer working life, etc.
MD bit is suitable for drilling at 90-300 RPM and is the ideal choice for directional, horizontal and horizontal multilateral well drilling applications.
Advantage of this Bit
– High Speed Floating Bearing and Metal Face Seal
– Higher ROP and longer working life
– To improve the bits stability, prevent bit diameter shrinkage, and extend the bits working life
B. PDC Drill Bits
1. Bit Size:
- Matrix Body: 3-1/2” to 17-1/2”
- Steel Body: 6” to 27”
- Cutter Size : 8mm, 11mm, 13mm, 16mm, 19mm, 22mm, 25mm
- Blade Number : From 3 to 10 More
2. Application of PDC Drill Bit
This bit incorporates proven design features to match the requirements of Rotary Steerable and Motor BHAs
– Rotary Steerable & Steerable Motor Design:
The low Make-Up-Length to Bit Diameter Ratio and directional gauge pad design provide excellent transfer of steering forces to achieve the required dog leg severity.
– Force Balanced Cutting Structure:
The bit cutting structure is balanced utilizing proprietary software. This maximizes drill bit stability ensuring any available drilling energy is effectively transferred to the cutting edge to shear the rock for high penetration rates.
– Trident Cutter Technology:
Trident cutters offer the latest technology for higher resistance to abrasion and impact. Field testing demonstrates improvements can be as much as 50% more footage drilled and 30% higher rates of penetration.
– Steel Body Bits:
Are designed to maximize Junk Slot Area (JSA) and Face Volume (FV) by taking advantage of high strength steel alloy material properties. Abrasion resistant hardfacing is welded around the cutter pockets and up the blade front to prevent cutter loss and maximize bit life. The combination of Steel & Hardfacing assists to maximize drilling efficiency in balling prone applications, possibly due to swelling clay, high mud weight, low flow rate or H.S.I.
– Matrix Body Bits:
Provides the greatest abrasion resistance in abrasive environments, such as high solids content or formations with quartz. Higher body abrasion resistance reduces matrix loss between cutters and increases drilling hours for longer drilling up to total depth. Likewise, matrix body bits offer the potential for additional playability and lower cost per foot.
– Diamond Gauge Protection:
The gauge pads are protected with abrasion resistant TSP diamond to ensure an in-gauge bit and stable directional response. This gauge feature is used on steel and matrix body bits.
C. Benefits of using Drill Bits
1. High performance bit cutters with good wear resistance, impact resistance, and thermostability is designed so that overall performance of cutting element is improved.
2. High performance matrix body material is designed to improve ability of body’s abrasive resistance.
3. Crown profile and cutters placement are optimized brings the bit with higher abrasive resistance ability and impact resistance ability in medium and medium-hard formation.
4. Hydraulic system of the bit is optimized and cooling effects of the bit is improved to prevent the compact failure under high temperature.
5. Optimized Hydraulic design and enhanced cleaning and cooling effects of the bit to prevent bit from balling.
6. The bit’s body material is made of steel of high quality. The good steel material and thinner blade design as well as deeper junk slot design helps to get higher ROP.
7. Wear-resistant materials are hardfaced on the surface of blade which can prevent body materials erosion.
8. From enhanced gauge protection, depth-of-cut control technology, optimized cutting structures to innovative anti-balling designs, our full line of PDC drill bits offer a wide range of solutions to the most common drilling problems. Our PDC drill bits provide greater drilling efficiencies and lower cost per foot.
9. Field proven legacy design products which offer excellent performance. Where bit cost is a considerable portion of the overall drilling costs, this cost-effective product line delivers a good balance of durability and aggressiveness for optimum performance at a minimal cost.
