CHAPTER 1 — PART 2 Flashcards
• Used to rotate the drillstring, therefore, the drillbit
• Includes all equipment used to achieve bit rotation; consists of rotary table, Kelly, and the swivel
• Modern drilling rigs use the top drive system.
Rotary System
Rotary Table or Kelly System Components
• Swivel
• Kelly
• Kelly Saver Sub
• Kelly Bushing
• Drillpipes (joints, stands)
• Rotary Table
• Slips
• Tongs
• The mechanical device suspending the drillstring’s weight
• Designed to allow drillstring rotation
• Allows the circulation of high-pressure drilling fluids while the drillstring is rotating.
Swivel
• Long square or hexagonal steel bar with a fluid path drilled through the center
• Transmits rotary motion from the rotary table or kelly bushing to the drillstring, while allowing the drillstring to be lowered or raised during rotation
• Goes through the kelly bushing, which is driven by the rotary table
Kelly
The ___ has an inside profile matching the kelly’s outside profile, but with slightly larger dimensions so that the kelly can freely move up and down inside.
kelly bushing
• Short drill collar with male threads on one end and female on the other
• Screwed onto the bottom of the kelly or topdrive and onto the rest of the drillstring
• Serves as a sacrificial element between the drill string and Top Drive or Kelly, reducing any unwanted repair and maintenance costs.
Kelly Saver Sub
• Adapter connecting the rotary table to the kelly
• Has an inside diameter profile that matches that of the kelly, usually square or hexagonal
• Connected to the rotary table by four large steel pins that fit into mating holes in the rotary table
• Rotation is transmitted to the bushing through the pins, and then to the kelly itself through the square or hexagonal flat surfaces between
the kelly and the kelly bushing.
Kelly Bushing
• Revolving or spinning section of the drillfloor that provides power to turn the drillstring in a clockwise direction (as viewed from above)
• Rotary motion and power are transmitted through the kelly bushing and the kelly to the drillstring
• Almost all rigs today have a rotary table, either as primary or backup system for rotating the drillstring.
Rotary Table
• Device used to grip the drillstring and suspend it in the rotary table when making or breaking a connection
• Consists of three or more steel wedges that are hinged together, forming a near circle around the drillpipe
• On the drillpipe side (inside surface), the slips are fitted with replaceable, hardened tool steel teeth that embed slightly into the side of the pipe.
Slips
• Large-capacity, self-locking wrenches for grippin drillstring components and applying torque
• As with opposing pipe wrenches for a plumber, the tongs must be used in opposing pairs
• While the tools are functionally identical, drilling sites typically have designated tongs for makeup and breakout.
Tongs
____ are the active tongs during breakout (or loosening) operations
Breakout tongs
___ are active during makeup (or tightening) operations.
Makeup tongs
• A drillstring turning device
• 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
• Suspended from the hook, so the rotary mechanism is free to travel up and down the derrick
Top Drive or Power Swivel
Advantages of top drive system
• When tripping out of the hole the power swivel is stabbed into the string with ease to allow circulation and string rotation when pulling out of hole, if necessary (e.g. to prevent stuck pipe)
• The top drive enables drillers to minimize both frequency and cost per incident of stuck pipe
The formation pressure is defined as the pressure at which a fluid or gas exists in the pores of a permeable rock. This is also called pore pressure.
Formation Pressure
The formation pressure is defined as the pressure at which a fluid or gas exists in the pores of a permeable rock. This is also called pore pressure.
Formation Pressure
The amount of pressure a formation can withstand before the formation breaks down as a fracture is initiated, followed by loss of fluid, also defined as Formation breakdown pressure.
Fracture Pressure
The amount of pressure the formation can withstand before the formation accepts any fluids.
Leak-Off Pressure
it prevents uncontrolled influx of formation fluid into the well i.e., kick
Well Control System
Well Control System is esigned to:
• Detect a kick
• Close-in the well at surface
• Remove the formation fluid which has flowed into the well
• Make the well safe
Failure to control a kick results in a ___ causing loss of lives and equipment, damage to the environment, and loss of oil or gas reserves.
blow-out
A combination of one or more Well Barrier Elements that together constitute a method of containment of fluids within a well that prevents uncontrolled flow of fluids into another formation, or, to escape at surface.
Well Barrier Envelope
___ is achieved by ensuring that the mud
hydrostatic pressure overcomes formation pore pressures. To maintain it, the well should always be filled with mud with a density within the mud window.
Primary Well Control
___ is achieved by using valves to prevent
the flow of fluid from the well until such time as the well can be
made safe.
Secondary Well Control
A flow of formation fluids into the wellbore during drilling operations.
Kick
Signs of a kick:
- Sudden increase in mud pit level
- Well is flowing despite pump off scenarios i.e., mud circulation is off
- Pit level indicators or mud flowmeters are triggered
what means BOP in well control system
Blow-out preventors
what must be installed to cope with any kicks that may occur?
Blow-out preventors (BOPs)
A ___ is a large valve at the top of a well that may be closed if the drilling crew loses control of formation fluids.
blowout preventor
On land rigs or fixed platforms the BOP stack is located directly beneath the ___
rig floor
On floating rigs, like semisubs and drillships, the BOP stack is installed on the ___
sea bed
Two basic types of BOPs
• Annular Preventor
• Ram Preventor
• designed to seal off the annulus between the drillstring and the side of hole
• may also seal off open hole if kick occurs while the pipe is out of the hole
• made of synthetic rubber which, when expanded, will seal off the cavity
Annular Preventor
• Designed to seal off the annulus by ramming large rubberfaced blocks of steel together
• Each ram set is configured as an opposing pair and, depending on function, are designed to close within the bore of the preventer
• Ram preventers are commonly available in single-, double-, triple- and quad-ram configurations
Ram Preventors
Types of ram BOPs include:
• Blind rams
• Pipe rams
• Shear rams
• Variable bore rams
Types of ram BOPs include:
• Blind rams
• Pipe rams
• Shear rams
• Variable bore rams
seal off open holes
Blind rams
seal off around drill pipe
Pipe rams
sever drill pipe
Shear rams
seals a range of tubular sizes
Variable bore rams
spacers between preventers that provide hookups for the choke line and kill line during a kick
Drilling Spool
Other Well Control Tools and Equipment
• Accumulator Unit
• Choke Manifold
• Kill Line
• Choke Line
• Mud Gas Separator
a hydraulic pressure unit that keeps liquid under pressure in the tanks and provides a method to open and close the blowout preventers quickly and reliably.
Accumulator Unit
an arrangement of piping and special valves, called choke. In drilling mud is circulated in the choke manifold when a kick occurs.
Choke Manifold
attached to the blowout preventer stack, usually directly opposite the choke manifold. Heavy weight fluid is pumped to the kill line into the well bore until balance has been restored.
Kill Line
a pipe attached to the blowout preventer stack out of which kick fluids and mud can be pumped to the choke manifold when blowout preventer is closed in on a kick.
Choke Line
device that is used to remove gas from the mud coming out of a well when kick is being circulating out.
Mud Gas Separator
Volume Detection Method for the Drilling Fluid
• After invasion of formation fluids into the wellbore, the total volume of drilling fluid increases, and the level of the drilling fluid tank rises
• the main instruments for monitoring the liquid level are float-level gauges and ultrasonic-level sensors
• These sensors are installed in each drilling fluid tank to monitor its level, thus the cumulative volume changes of the drilling fluid can be obtained.
___ is also one of the means to detect the kick
Flow detection method for returning drilling fluid
The commonly used means of detection is the ___, but also electromagnetic flowmeter and mass flowmeter detection are used.
target-type flowmeter
___ can be sent downwards along the wellbore, this signal will be reflected on the gas-liquid interface in the wellbore, and the reflected wave will reach the receiving equipment upwards along the wellbore
Acoustic wave signals
What principle can be used to detect top level
of mud if there is a total loss
By measuring the time difference between the transmitting time of the acoustic wave and the receiving time, the drilling fluid in the wellbore (from surface/wellhead) can be calculated.
___ inspect rock cuttings from the shale shaker at regular intervals. They also monitor the gas present in the mud by using gas chromatography.
Mudloggers
This log is useful to the geologist in correlating this well with others in the
vicinity.
Mudlogging
