Technology Value Guide IADC Advanced Rig Technology Reliability & Guidelines Subcommittee

The IADC Technology Value Guide is intended to suggest positive aspects of various types of well-construction technologies, as well as point out potential drawbacks. In addition, each technology listed (column headers) in the TVG is linked to separate pages containing definitions, illustrations and training resources.

IADC encourages its members to provide feedback on the TVG, and to supply relevant illustrations and training resources. The TVG is an evergreen document, and IADC are open to contributions. For more information, please email

Two & Three
Arm System
Column Racker /
Dual Vertical
Auto Mud
Horizontal To
Vertical Pipe
Transfer Arm
Drill Floor
Top Drive
Casing Running
Active Heave
Active Heave
Mud Pump
Pipedeck Operator/
Standbuilding Chair
AC Drives Automatic
Positives Hands Free          
Better Working Environment  
Improved Ergonomics      
Adds Efficiency        
Safer Operation
All Weather
Personnel Elimination                                  
Automatic Sequences    
Local Condition Monitoring                     
Weight Reduction                                                                  
Manual Back-Up                                    
Remote Condition Monitoring                            
Negatives Additional Space Required                  
Additional Weight                  
Down Time if Equipment Fails                    
Major Spares Purchase Required                                                      
Major Additional Electric / Hydraulic Power Required                                          
Special Training Required                            
OEM Service Required                            
OEM Startup Required                  
Additional Personnel                                                            
Land Rig                              
Jack Up      
  Introduction Decade 1980 1990 1970 1970 1970 1960 1960 1980 1990 1990 1990 1990 1970 1970 1960 1990 1960 1990 1990 1980 1990 1980 1990 2000 2000 1980 1970 1990 1990 1990 2000 1990 1980 1990 1990
Approximate Field Population 1000+ <50 1000+ 1000+ 1000+ <100 <1000 <1000 <100 <50 <50 <1000 <100 <1000 <1000 <1000 <1000 <100 <1000 <1000 <50 <100 <50 <50 <50 <100 1000+ <1000 <100 <50 <50 <50 <50 <1000 1000+
Rental Item                                                  


Yes (has the ability to have this functionality)


The IADC Technology Value Guide is intended to provide general information regarding the positive and negative aspects of key well-construction technologies.


Top Drive

Figure 1" National Oilwell Varco (NOV) top drive. Courtesy of NOV.

Top drive systems primarily function like a power swivel, applying rotary torque to the drill pipe at the top of the drill string. Some early top drives are suspended below a separate rotary swivel, while some have an integrated swivel. The prime difference from a power swivel is the power, load rating, and ability to connect the stand or drill string to the powered main shaft at well center without human intervention through the use of a "pipe handler" under the top drive. This facilitates drilling ahead with stands of drillpipe where prior to this all connections had to be made at the drill floor which meant only one single from the rathole could be added at a time. Top Drives are an alternative to Kelly drive systems powered by a rotary table. Top drives also provide improved back reaming capability to aid in pulling out of the well while rotating. Top Drives allow both pumping and rotating during hoisting, making it possible to pull out of a wellbore with mechanical obstructions. Additionally, a remote kelly cock, or integrated BOP valve, is connected to the top drive main shaft and can be remotely actuated from the driller's console. Top drives are generally rated for hoisting loads at 150 ton, 250 ton, 350 ton, 500 ton, 750 ton, 1000 ton, and 1250 ton. A rotary table is occasionally still used for a back-up rotation system, or as a method to turn casing in the well while adding a joint of casing to the string to avoid potential sticking problems. In a few cases no rotary exists and a simple device to handle the slips is put in its place at well center on the rig floor.

Training (examples):
Aker Solutions
National Oilwell Varco
TTS Sense

Figures 2 & 3: At bottom, Aker Solutionís MH DDM 1000 ACô top drive. At left, Akerís MH MDDM 1000 ACô top drive. Courtesy of Aker Solutions.

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Figure 4: Transocean Discoverer Enterprise. Courtesy of Transocean.

The use of machines to facilitate simultaneous activities in a safe manner, such as offline standbuilding while drilling ahead and running a BOP in deepwater operations while drilling tophole. The challenge associated with multi-activity operations usually includes number of operators required as well as safety systems to manage potential interference between machinery and personnel.

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Power Slips (see slips)

Figure 5: NOV PS-30 Power Slips. Courtesy of NOV.

Slips: Wedge-shaped pieces of metal with serrated inserts (dies) or other gripping elements, such as serrated buttons, that suspend the drill pipe or drill collars in the master bushing of the rotary table when it is necessary to disconnect the drill stem from the kelly or from the top-drive unitís drive shaft. Rotary slips fit around the drill pipe and wedge against the master bushing to support the pipe. Drill collar slips fit around a drill collar and wedge against the master bushing to support the drill collar. Power slips are pneumatically or hydraulically actuated devices that allow the crew to dispense with the manual handling of slips when making a connection.

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Power Elevators

Figure 6: NOV BX-4-75 Power Elevator. Courtesy of NOV.

These are air or hydraulic elevators operated on bails hanging below the traveling equipment, which provide a remote opening and closing of the elevator without human intervention.

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Mechanized Roughneck

Figure 7: Canrig mechanized roughneck. Courtesy of Canrig.

A machine that integrates the function of a spinning wrench and a torque wrench to make up and break out drill pipe connections. These machines evolved to replace manual connections and increase the safety of making and breaking connections by eliminating the manual handling involved with suspended individual tools. The machine may be configured as a single wire hung device or as an arm-deployed or floor rail-mounted device to facilitate the continual hydraulic movement of the machine in and out from a well center, mousehole, and in some cases the rathole location. Some larger machines incorporate pipe thread doping and cleaning systems, bit breakers, mud buckets and full remote control and/or automated operations. Some machines adapt to connect casing tong mechanisms and some cover a full range of tubular and casing up to 20Ē.


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Upper Racking Arm


Figure 8: TTS Energy Multifunctional Roughneck. Courtesy of TTS Energy.

Functionally replaces the derrickman in guiding pipe from the set-back to the travelling equipment. Some systems have hoist mechanisms and some work in conjunction with an intermediate and lower arm. These machines are remote controlled or operate in semi- or fully-automated mode from a derrick mounted station/cabin or a floor mounted station/cabin or a driller's station integrated control system.

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Two and Three Arm System

A two arm system is the combination of an upper tailing arm and an intermediate hoisting/racking arm. A three arm system is the combination of a two arm system and a lower racking arm often added to aid in stability of handling drillpipe on a floating vessel, and some systems also use the lower racking arm as a riser tailing device. Each arm (in most cases) is independently controlled in a separate cabin or control station. Usually the arms are hydraulic systems used in conjunction with an air or hydraulic-operated latched fingerboard.

Upper Tailing Arm: A heavy duty guide arm used as an upper racking arm to replace the derrickman's function of manually moving stands of drill pipe from the fingerboard to the elevators and back. It does not hoist the stand. The upper tailing arm is usually installed underneath the diving board between the fingerboards and operated by a man standing on the diving board or standing on the drill floor. Generally used on land rigs or smaller jack up offshore rigs where there is no to limited rig motion
Intermediate Racking Arm: Usually the hoisting mechanical device in a two or three arm pipehandling system connected to the derrick in the middle of the set-back, guiding the center of a drilling stand between the set back stored position and the well center. The arm is usually controlled locally or integrated in an automated or semi-automated system ran from the drill floor or in the driller's cabin.
Lower Racking Arm: Primarily a guide arm often used as a second or third arm in a pipehandling system. The arm is usually controlled locally or integrated in an automated or semi-automated system ran from the drill floor or in the drillerís cabin.
Lower Tailing Arm: A heavy duty guide arm. Sometimes used as a lower racking arm but primarily used for the tailing and guiding of the riser on a floating vessel and as a general heavy lifting crane. Usually on the rig floor or suspended slightly above the rig floor.

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Column Racker/Synchronized Racker


Figure 9: TTS Energy Smart Racker. Courtesy of TTS Energy.

An automated system of arms on a column that can be a fixed rotating (radial pattern) machine or a traveling and rotating machine. Usually consists of a single guide and single gripping hoist arm and has a primary function of tripping the pipe without the intervention of human labor. Various modes and versions exist with additional functionality including additional arms and tools to facilitate stand-building off-line, riser tailing, riser tripping (stands of riser), casing tripping (stands of casing) and integrated Iron Roughnecks. Three fingerboard designs are common, the star fingerboard, where the column is a fixed rotating design and the arms place the pipe in a radial fashion, the X-Y fingerboard which mimics the traditional left-hand, right hand fingerboard with the exception of each stand or a number of stands are locked in place with a remotely controlled finger latch, or a parallel fingerboard where all the fingers point towards well center and the racker travels in front of the set back rotating 180 degrees to present the tubular stand at well center (this system also latches like the X-Y fingerboard. These systems are prevalent on high-spec offshore rigs and floating vessels where the lateral stand loads are too high for typical manual operations by a derrickman.

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Dual Vertical Rackers

In a parallel racking system often the design will include a second racker on the same track system. This is to facilitate redundancy as well as efficiency of a rig that can build stands off-line while tripping in or out of the well.

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Auto Mud Bucket

A mechanized or automated mud capturing device that also serves as a spray protection for the crew when pulling a wet string tripping out of the hole. Typically mounted on the drill floor where it is actuated to well center or on an Iron Roughneck that brings it to well center during deployment. The captured mud is returned to the pits, reducing waste and cost.

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Auto Doper

A remote controlled or automated system for cleaning and lubricating the drill pipe connections while tripping in the hole. Often times connected to an Iron Roughneck.

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Offline Stand-Building

A process that incorporates machines to facilitate the construction of stands of drillpipe away from the activities at well center. This may be done vertically using one or more mousehole. This can also be done horizontally. This is done independently, or in a parallel process, of normal drilling.

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Horizontal to Vertical Pipe Transfer Arm

Figure 10: Canrig horizontal to vertical pipe transfer arm. Courtesy of Canrig.

Horizontal to Vertical Pipe Transfer Arm: A device designed to transition a single tubular (and in a few cases whole stands) between a horizontal or angled presentation and a vertical position in a mousehole or at well center. The machine is usually integrated in to a V-door.

Pipehandling Boom: An arm-based machine that usually transitions drill pipe from the horizontal to the vertical position in a single motion. It is usually rotated around a fixed pivot point in the sub structure and is mostly used in land rig applications.

Figure 11: Courtesy of Precision Drilling Oilfield Services Corp.

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Casing Stabbing Arm

A derrick- or mast-fixed arm that is deployed solely for running casing. It provides stability and control in the running of casing singles.

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Drill Floor Manipulator Arm

An extending or telescoping arm with attachable heads, used to guide riser to well center, manipulate tubulars or other items about the drill floor

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Top Drive Casing Running System

Figure 12a: NOV CRT-350 Casing Running Tool. Courtesy of NOV.

Figure 12b: Photo of Volant Casing Running Tool (internal) CRTi courtesy Volant Products.

An adaptor that attaches to the top drive eliminating floor tongs and manual handling of casing using the power and rotation from the top drive. When connected to the top of the casing it is used to spin in and make-up the connection of the casing accurately. This system may also include a casing fill-up and/or casing circulation function. A floor based method of holding adequate back up or a slip system is needed to react to the torque in the string as the top drive is made up to the upper casing joint.

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Horizontal Tubular Transfer

Horizontal Tubular Transfer: A horizontal or angled machine that transfers tubulars from the pipe deck/rack to the rig floor, often achieved with carts, carriages, rollers, or belts.

Pipe Conveyor: A type of horizontal tubular transfer generally using a continuous belt to convey the tubulars along the machine. Pipe Conveyors can utilize only a belt that is loaded directly with a tubular handling crane, while others also include side loading arms that transfer the pipe between the tubular handling crane and belt.

Catwalk Machine: A horizontal pipe and/or riser handling system which transports tubulars and/or risers in and out of the rig floor. Typically these machines are mounted at the drill floor elevation and are loaded with a deck crane or dedicated tubular handling crane.

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Tubular Handling Machine (for pipe decks/racks)

A tubular handling machine is a pipe deck tubular handling arm, some of which handle one joint of pipe at a time and some which handle bundles; however, these are uniquely identified by the ability to handle tubulars on the pipe deck/rack mechanically to connect to the pipe. These machines typically interface with Pipe conveyors or pipe catwalk machines.

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Powered Mousehole

The utility functions associated with a traditional mousehole, such as hoisting, lowering, rotating, and grabbing or actuating with a slip assembly. Usually associated with facilitating offline standbuilding activities.

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Integrated Control Cabin

Figure 13: Courtesy of Canrig.

An enclosure for remotely controlling equipment. Generally (but not always) used to describe a Driller's cabin. The enclosure typically includes both controls and instrumentation at an Operator's workstation. These cabins have included controlled environment features such as heating and/or air conditioning. Cabins commonly have windows to see operations and may also be augmented with video displays for cameras showing areas difficult to see directly. The enclosure may also be purged to maintain a safe level of flammable gases or vapors by positive pressure or continuous flow. Integrated control cabins also often have some method of communicating with the rig floor integrated into the system. Often associated with an integrated control cabin is a control chair(s) for the driller with additional stations for pipehandling functions or redundancy. Ergonomics are also considered to help eliminate operator fatigue. The amount of stations ranges from just the drillerís station up to five stations on a multi-activity deepwater drillship.

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Cylinder Rig

A rig that utilizes a hydraulic powered hoisting system having long stroke cylinders for pushing a sheave cluster and traveling assembly vertically. These cylinders and sheave cluster are guided by a guide frame to allow the sheave cluster to raise and lower the top drive and elevator during drilling operations. The number of cylinders is determined by the load capacity. The Cylinder Rig is an alternative system to the conventional drawworks, derrick, and crown-mounted motion compensation systems. Since the hydraulic cylinders carry the load, no derrick structure is required. However, the top drive will need a guiding structure for travel and to absorb Torque.

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Active Heave Compensator

An additional device that can be installed on a passive heave compensator system, such as a crown-mounted or drill string compensator. It is designed to improve the performance and accuracy of the passive compensator during critical sea bed landings and critical weight on bit requirements.

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Active Heave Drawworks

Figure 14: NOV AHD-1250 Active Heave Drawworks. Courtesy of NOV.

A drawworks with an advanced controls system and additional power to provide the heave compensation of the string on a floating vessel instead of the traditional crown-mounted or drill-string motion compensation systems. Through use of the reference frame system, the drawworks is activated via the control system forwards and backwards to move the top drive, string, riser, etc. to maintain a static position relative to the ocean floor.

Dual Active Heave Drawworks System: utilization of two active heave drawworks to provide full load compensation without the need of a crown-mounted compensation system and to increase the speed of the traveling assembly.

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Mud Pump Synchronization

A control arrangement to gradually phase the speed of all the active mud pumps so that all the pistons are travelling in a synchronized fashion to smooth out the average flow and pressure pulsations down the drillpipe.

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Automatic Relief Valve

A remotely controlled, actuated, and/or reset high pressure mud pump discharge relief valve. This system may be remotely operated or controlled electronically, pneumatically, hydraulically or in some other manner.

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BOP Multiplex Controls

An electronic system for communicating critical control functions from the rig floor to the BOP stack. The system incorporates two communicating controllers, one receiving a command from the rig floor and translating that command to the second controller, which verifies receipt of the command on the BOP stack, and in turn converts the electrical signal into a hydraulic function. The reason for using these systems is primarily in deepwater applications in excess of 4000 feet where response speed becomes a critical issue. The traditional methods of using hydraulics/pneumatics to transfer this signal over long distances are no longer sufficient. From four to seven thousand feet this is being carried out with an electrical signal, however beyond 7000 feet, these systems are using fiber optics to achieve sufficient response times. On some jackups, multiplex controls are used to eliminate cable runs between the control system in the hull and the cantilever based BOP stack.

GE Oil & Gas

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Downhole Telemetry

Signals transmitted in real-time (while drilling) from an instrument located near the bottom of the drill string to a receiving monitor on the surface (a surface-readout). Downhole telemetry may be transmitted via mud pulses (much as sonar signals are transmitted through water), through electro-mechanical methods (radio transmission) or via a wire within the drillpipe. Frequently, downhole telemetry is employed in determining the drift angle and direction of a deviated wellbore. The signal from the downhole tool to the surface is called an uplink. (See measurement while drilling)

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Drillerís Chair

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Assistant Drillerís Chair

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Pipedeck Operator/Standbuilding Chair

Figure 15: NOV pipedeck operator/standbuilding chair. Courtesy of NOV.



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Auto Shaker Control

A PLC controlled flow distribution and remote valve controlled system to ensure even flow distribution to all shakers including a start up procedure when flow is increasing or a stop procedure when flow is decreasing.

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Auto Mixing System

A system of a control unit and drilling mud mixing equipment where the drilling mud mixing process can be automated, either to preset drilling mud properties or to automatically control and mixing of drilling mud properties while drilling. For instance, measurements of downhole and surface parameters can be used to automatically adjust the mud conditions while drilling if well conditions changes.

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Auto Sack Cutter

A system with an automatic dustproof machine able to cut smaller sacks with powder. It will separate powder into a feeding unit towards the mud mixer and packaging into a waste material compacting unit. This slitter unit is often integrated in a mud mixing system with lifting table for pallets and a PLC controlled system with a local control panel. All this often delivered on a skid for easy installation into the Mud Mix room/area.

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AC Drives

Figure 16: Omron Oilfield and Marine AC Drive (VFD). Courtesy of Omron.

An AC Drive is a system for controlling the rotational speed and/or torque of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor.


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Automatic Driller

Automatic Driller: A mechanism used to regulate the amount of weight on the bit without the continual control by drilling personnel. Automatic drillers free the driller from the sometimes tedious task of manipulating the drawworks brake to maintain correct weight on the bit. It may also have the capability to control weight within safe operating limits when more than one drilling parameter changes at a time.


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Definition Sources

Precision Drilling
TTS Energy

*Other companies/individuals were invited to participate and chose not to.

Figure Sources

1. National Oilwell Varco top drive
2 & 3. Aker Solutions
4. Transocean Discoverer Enterprise
5. National Oilwell Varco PS-30 Power Slips
6. National Oilwell Varco BX-4-75 Power Elevator
7. Canrig mechanized roughneck
8. TTS Energy Multifunctional Roughneck
9. TTS Energy Smart Racker
10. Canrig horizontal to vertical pipe transfer arm
11. Precision Drilling Oilfield Services Corp.
12. National Oilwell Varco CRT-350 Casing Running Tool
13. Canrig
14. National Oilwell Varco AHD-1250 Active Heave Drawworks
15. National Oilwell Varco pipedeck operator/standbuilding chair
16. Omron Oilfield and Marine AC Drive (VFD)