Hello Pulkit,
Here are my suggestions for check list, considering the cost effective criteria.
Total depth
The hole
size will give you the drill bit size then the required hydraulic horse power is obtained and finally the mud pump equipment can be selected.
Rule of thumb: Hydraulic horse power = 3-5 hhp/sq.
in of bit diameter
Assume 65% of the available surface horsepower when bit
horsepower is being maximized
Drill
pipe
Bigger the size of the DP the less circulation loses which then has to be
balanced against cost and weight.
Casing
Program
Potential Hole Problems:
a. Shale sloughing will require more bottom hole cleaning therefore
the calculated available surface horsepower must be corrected accordingly (increased)
b. Pipe stuck will require a higher derrick loads therefore the
safety factor for derrick loads must be increased
Derrick maximum hook load capacity – under what conditions the ratings are
made when comparing them.
If in doubt an API certified inspector should verify all
ratings:
- Check if the rating is made for a certain type of crown/travelling-block
line configuration or not)
- Check for leg loading, substructure rating, maximum wind
loading with drill pipe in the derrick.
Drawworks horse power rating applicability rests primarily on the necessary time to hoist a load rather then actual ability to hoist the load.
The power required to stop a load in free fall can be far greater
than the drawworks capacity
Triplex Mud Pumps
- Are
much lighter than duplex for the same horsepower rating (e.g. 70 lbs vs. 400 lbs)
- Can
operate at higher pressure with fewer fluctuations
Horse power rating is based on input horsepower but when make
the selection it is the output horsepower that is relevant (it will give the maximum
values for pressure and flowrate).
Also, the contractor must provide the maximum sustained levels
at which the pump has run which allows an adequate pump selection and planning
the hydraulics program.
Drillpipe
Discuss with the firm that performed the last inspection and
if in doubt require an inspection to be run.
Mud system
Tank capacity needed in the active system
The rule of thumb is the total pipe displacement at the projected
total depth multiplied by 2.5
Centrifugal pump is the most preferred option for a good
mud mixing and stirring.
Select the solid control equipment needed based on the performed analyze.
Auxiliary equipment (e.g. degasser, mixing tanks, chemical barrel,
charging pumps, pit level indicator) hast to be inventoried and ask for the absence
of equipment, if applicable.
BOP
- Check the ratings not only for the BOP but for lines
connections, and valves
- Check the availability for the annular and rotating
preventers, choke manifold, accumulator, remote and direct controls, choke and
kill lines.
- Make a sketch of BOP system to ensure the adequacy of the system
Power package
If the required horsepower is greater than 1,000 a diesel
electric generator is selected.
Power allocation between rig components is more efficient.
I hope this will help you out.
Dan
