|
Prior to commencing the rig-up
process, the conductor, rathole and mousehole are completed.
Special companies may be hired
to begin drilling these three holes.
|
![Fig. 1. Conductor hole Fig. 1. Conductor hole](https://webarchive.library.unt.edu/web/20120926165200im_/http://www.osha.gov/SLTC/etools/oilandgas/images/conductor_casing.jpg)
Fig. 1. Conductor hole
|
Conductor Hole and Conductor
Pipe |
![Fig. 2. Installing conductor hole casing Fig. 2. Installing conductor hole casing](https://webarchive.library.unt.edu/web/20120926165200im_/http://www.osha.gov/SLTC/etools/oilandgas/images/casing_cond_hole.jpg)
Fig. 2. Installing conductor hole casing
|
This is a large diameter hole, lined with pipe, also called a starter hole,
varies in depth down of tens of feet to a few hundred feet depending on the
local geology.
Some sites do not require a conductor hole.
Potential Hazard:
- Being struck by hoisting line or suspended drill or
casing.
Possible Solutions:
|
Rathole |
![Fig. 3. Rat hole - covered Fig. 3. Rat hole - covered](https://webarchive.library.unt.edu/web/20120926165200im_/http://www.osha.gov/SLTC/etools/oilandgas/images/conductor_rat_hole.jpg)
Fig. 3. Rat hole - covered |
A
rathole is a hole in the rig floor, 30 to 35 feet
deep, lined with casing that projects above the floor, into which the
kelly is placed when hoisting operations
are in progress.
This is either done by the portable rig that drills the conductor
hole or can be done by the primary rig after rigging-up.
Potential Hazard:
- Falling or stepping into an uncovered rathole.
Possible Solution:
- Cover the hole until it is lined with casing or other material
during rigging-up.
|
Mousehole |
![Fig. 4. Mousehole - covered Fig. 4. Mousehole - covered](https://webarchive.library.unt.edu/web/20120926165200im_/http://www.osha.gov/SLTC/etools/oilandgas/images/mousehole.jpg)
Fig. 4. Mousehole - covered |
A
mousehole is a shallow bore hole under the rig floor,
usually lined with pipe, in which joints of drill pipe are temporarily placed.
This is either done by the portable rig that drills the conductor
hole or can be done by the drilling rig after rigging-up.
Potential Hazard:
- Falling or stepping into an uncovered mousehole.
Possible Solution:
- Cover the hole until it is lined with casing or other material
during rigging-up.
|
|
|