CORRECT ANSWERS
A device that turns the drillstring. It consists of one or more motors (electric or hydraulic)
connected with appropriate gearing to a short section of pipe called a quill, that in turn may be
screwed into a saver sub or the drillstring itself. - CORRECT ANSWERS topdrive
A dug-out area, possibly lined with wood, cement or very large diameter (6 ft [1.8 m]) thin-wall
pipe, located below the rig. It serves as a cavity in which the casing spool and casinghead reside
- CORRECT ANSWERS cellar
An electric motor that acts as a brake. Braking is accomplished by reversing the electric fields on
the motor, effectively turning it into a generator. The usage of the generated power, either in
useful applications or dissipation as heat, restrains the motor-turned-generator and provides a
braking action - CORRECT ANSWERS electrodynamic brake
To pump the drilling fluid until a sample from the bottom of the hole reaches the surface. This is
commonly performed when drilling has ceased so that the wellsite geologist may collect a
cuttings sample from the formation being drilled, or when the driller suspects that a small
amount of gas has entered the wellbore. - CORRECT ANSWERS circulate out
The use of a mill or similar downhole tool to cut and remove material from equipment or tools
located in the wellbore. - CORRECT ANSWERS milling
The complete operation of removing the drillstring from the wellbore and running it back in the
hole. This operation is typically undertaken when the bit becomes dull or broken, and no longer
drills the rock efficiently. - CORRECT ANSWERS round trip
,An average or baseline measure of gas entrained in circulating mud. This baseline trend pertains
to gas that is liberated downhole while drilling through a uniform lithologic interval at a
constant rate of penetration. - CORRECT ANSWERS background gas / BGG
The set of sheaves that move up and down in the derrick. - CORRECT ANSWERS traveling
block
the angle, or azimuth, of the borehole survey instrument within the wellbore measured
clockwise relative to magnetic north and in the plane perpendicular to the wellbore axis; -
CORRECT ANSWERS magnetic tool face
A drill bit, usually polycrystalline diamond compact bit (PDC) type, designed such that the
individual cutting elements on the bit create a net imbalance force. This imbalance force pushes
the bit against the side of the borehole, which in turn creates a stable rotating condition that
resists backwards whirling, wobbling and downhole vibration. - CORRECT
ANSWERS antiwhirl bit
Large capacity self-locking wrenches used to grip drillstring components and apply torque. -
CORRECT ANSWERS breakout tongs
The system of spools, valves and assorted adapters that provide pressure control of a
production well. - CORRECT ANSWERS wellhead
The threaded collar used to connect two joints of casing. The resulting connection must provide
adequate mechanical strength to enable the casing string to be run and cemented in place. -
CORRECT ANSWERS casing collar
To tighten threaded connections. - CORRECT ANSWERS make up
,A representation of the integrity of the cement job, especially whether the cement is adhering
solidly to the outside of the casing. The log is typically obtained from one of a variety of sonic-
type tools. - CORRECT ANSWERS cement bond log
The magnitude of pressure exerted on a formation that causes fluid to be forced into the
formation. The fluid may be flowing into the pore spaces of the rock or into cracks opened and
propagated into the formation by the fluid pressure. - CORRECT ANSWERS leak off
The reduced or total absence of fluid flow up the annulus when fluid is pumped through the
drillstring. Though the definitions of different operators vary, this reduction of flow may
generally be classified as seepage (less than 20 bbl/hr [3 m3/hr]), partial lost returns (greater
than 20 bbl/hr [3 m3/hr] but still some returns), and total lost returns (where no fluid comes
out of the annulus). - CORRECT ANSWERS lost circulation / lost return
A condition whereby the drillstring cannot be moved (rotated or reciprocated) along the axis of
the wellbore. It typically occurs when high-contact forces caused by low reservoir pressures,
high wellbore pressures, or both, are exerted over a sufficiently large area of the drillstring. -
CORRECT ANSWERS differential sticking
The angle measured in a plane perpendicular to the drillstring axis that is between a reference
direction on the drillstring and a fixed reference. - CORRECT ANSWERS toolface
A subset of the more general term "directional drilling," used where the departure of the
wellbore from vertical exceeds about 80 degrees. - CORRECT ANSWERS horizontal drilling
A procedure to determine the productive capacity, pressure, permeability or extent (or a
combination of these) of a hydrocarbon reservoir. - CORRECT ANSWERS drillstem test
, The upside down V-shaped opening in one side of the derrick that enables long pipes and tools
to be lifted into the interior of the derrick. This opening is aligned with the slide and catwalk of
the rig. - CORRECT ANSWERS vee door
One of the instruments that the driller uses to monitor and improve the operating efficiencies
of the drilling operation. The actual measurement of weight is made with a hydraulic gauge
attached to the dead line of the drilling line. - CORRECT ANSWERS weight indicator
A specially designed drilling rig capable of drilling directional wells - CORRECT
ANSWERS slant rig / slant hole rig
A wellbore that has not encountered hydrocarbons in economically producible quantities. -
CORRECT ANSWERS dry hole
A large valve used to control wellbore fluids. In this type of valve, the sealing element resembles
a large rubber doughnut that is mechanically squeezed inward to seal on either pipe (drill collar,
drillpipe, casing, or tubing) or the openhole. - CORRECT ANSWERS annular blowout
preventer
To take apart equipment for storage and portability. Equipment typically must be disconnected
from power sources, decoupled from pressurized systems, disassembled and moved off the rig
floor or even off location. - CORRECT ANSWERS rig down
An extraordinarily poisonous gas with a molecular formula of H2S. - CORRECT
ANSWERS hydrogen sulfide
The overnight work shift of a drilling crew - CORRECT ANSWERS graveyard tour