The MWD tool is an in-line drill collar that records at-the-bit drilling parameters and telemeters the drilling parameter data as well as data from other LWD tools to the surface in real-time. MWD measurements include weight on bit (WOB), rate of penetration (ROP), torque, and pump pressure.
The tool uses a continuous mud wave, or siren-type, telemetry method and incorporates design features and software that enable it to approach data transmission rates of 6 to 10 bits per second. It measures downhole weight and torque on the bit to help the driller maintain optimal weight on bit or torque and improve the penetration rate.
The use of MWD equipment in ODP is anticipated to improve core quality and increase core recovery by reducing the variability of weight on bit (WOB). Examples of improved core quality include reduced "biscuiting," reduced core breaks, and recovery of difficult lithologies.
|
Collar Size
|
6.75 in.
|
8.25-in
normal flow
|
|
API collar size:
|
6.75 in. |
8.25 in. |
|
Collar OD:
|
6.89 in. |
8.41 in. |
|
Collar ID:
|
5.109 in. |
5.109 in. |
|
Makeup length
|
23 ft. (without WOB) |
23 ft. (without WOB) |
|
Collar weight
without tool:
|
1330 (lbm) |
2590 (lbm) |
|
UH connection
bending strength ratio:
|
2.00 |
2.20 |
DH connection
bending strength ratio: |
2.14 |
2.20 |
| Moment of inertia: |
77.4 in.4 |
212 in.4 |
| Collar dogleg: |
5 deg/100 ft,
rotating at 100 rpm |
4.4 deg/100 ft,
rotating at 100 rpm |
| Max. collar dogleg: |
15 deg/100 ft,
sliding |
12 deg/100 ft,
sliding |
| Flow range: |
225-800 gpm |
300-800 gpm |
Maximum operating
torque: |
12,000 ft-lbf |
23,000 ft-lbf |
| Maximum weight on bit: |
71,000/L2 |
194,000/L2 |
| Maximum tensile load: |
550 klbf |
865 klbf |
* ®trademark of Schlumberger |
