1. Underbalance Drilling
Rotating Heads
&
Rotating BOP’s
Probably the basic tool for UB drilling is the rotating head or rotating blow
out preventer.

2. This is not a new tool as you can see by this old catalog from 1937
This is not a new tool as you can see by this old catalog from This model, which has no model number, was made for 13-3/8” casing and from 2” to 6” drill pipe.
It is essentially the same in principle as the Rotating Heads used today.

3. This is the 1954 catalog, and now they call it the Model 50 rotating and stripping head. I saw what appeared to bean old model 50 just a few years ago in Mexico.

4. Rotating Heads Rotating BOP’s
Used to divert the return flow stream down the blooey line, flow line or to the choke manifold.
The Rotating head or rotating bop is a diverter by definition. Sometimes we confuse it with a blow out preventor, and the trend is towards making them true annular blowout preventors..

5. Rotating Drilling Heads
Two types of systems; hydraulic active (RBOP) and mechanical sealing (RH)
Both are used successfully in air and underbalanced wells
There are two types of systems available on the commercial market today. They are a hydraulic actuated system and a mechanical seal system. Both refer to the system used to achieve a seal around the drill string. Both are used successfully in air, gas or underbalanced applications in low or high pressure regimes.
Hydraulic active systems use hydraulic closure, often electronically controlled. They are essentially active systems.
Mechanical sealing systems utilize the memory of a stretch fit stripper rubber assisted by well bore pressure. These are essentially passive systems

6. Rotating Head Mechanical Sealing Type
Section of a mechanical sealing system (Williams, Smith). The whole sleeve assembly rotates.
TT96-90
Gas and Air Drilling

7. Rotating Head Mechanical Sealing Mechanism
On the left we see the tight stretch seal of the rubber
On the right, well bore pressure makes the seal tighter in direct response to
the unit pressure in the well bore- psi, kPa, kG/m2
TT96-93
Drilling Fluid Description

8. Rotating BOP Hydraulic Active RBOPTM Kelly Packer
The hydraulically active Rotating blow Out Preventor uses hydraulic fluid to push a packer closed around the pipe. The closing pressure is set to be some amount higher than the well pressure. The whole packer assembly rotates.

9. Closing Unit
Here is the view of a hydraulic closing unit in a portable building. (Schaefer RBOP)

10. Manufacturers Williams Smith Grant Shaffer RSBOP (Varco)
Northland Inter-Tech
RBOP
TESCO1
Alpine - Technicorp
Lynn International
Others
The white names are rotating heads. The yellow are Rotating Blow Out Preventors
TESCO has a hydraulically closed annular preventor that does not rotate.

11. Mechanical Seal Rotating Heads
Pressure Ranges
Low 300psi
Medium 700psi
High 1500psi
Very High 3000psi
Static pressure ranges are twice as high
Static ranges are higher than rotating ranges. This is mostly a convention. Rotating at higher pressures causes more wear.

12. Mechanical Sealing Rotating Heads
Kelly Bushing
Drive Bushing
Swing Bolt Clamp
Stripper Rubber
The split kelly bushing is made up with a loose fit around the kelly. When the kelly is run in, this bushing automatically indexes itself inside the Drive Bushing. The rotary action of the kelly turns the bushing. The bushing turns the Drive Bushing, and consequently, the attached Stripper Rubber.
When the kelly is picked up, the shoulder on the lower kelly upset lifts the bushing with it. This automatically disengages the bushing from the drive bushing , and the bushing remains with the kelly in the rathole.
The stripper rubber is designed to seal off on all drill string components. The rubber expands and contracts (breathes) as the pipe, kelly, and tool joints are stripped in and out of the hole. Stands of drill pipe may be added or removed during tripping without loss of time since the drive bushing assembly is removed only for drill bits or special tools.
Grant - Smith

13. Conventional Rotating Head Williams Model 9000
Kelly Driver
500 psi rotating
Bearing Assembly
1000 psi static
Up to 200 rpm
Stripper Rubber
Geothermal model -
two stripper rubbers
Bowl
TT96-93
Drilling Fluid Description

14. Negative Impact to Stripper Rubber Elements
The purpose of the stripper rubber is to provide a seal around the kelly as it rotates and to seal around the drill pipe while tripping in or out of the hole.
The better the pipe condition supplied the more life can be expected in the stripper rubbers. Drillpipe condition is critical to a long lasting seal. Similar to tire wear, where pavement travel is less damaging to tires than travelling on gravel roads. More meterage of drill pipe can be tripped safely with good pipe and kelly conditions.

15. Stripper Rubber Composition
Natural- Air, Mist, Foam, Gas
Polyurethane- Oil Based below 140 F
Nitrile - Oil Based above 140 F
Butyl - Geothermal and H2S
One or two steel reinforced stretch-fit self actuating stripper rubber elements provide a robust seal around the drill string or kelly which allows annular fluids to be diverted to the flow line or a choke manifold. Rubber selection is varied based on drilling medium and dynamic pressures found on the drilling location, as well as temperature of drilling muds. Here we show the low pressure elements in natural rubber good to 500 psi dynamic rating. The composition of the elastomer can be varied to provide optimal protection from wellbore fluids, pressure and temperature. Both low pressure and high pressure elements are available in natural, nitrile, butyl, or polyurethane compositions.
The shape of the element is also designed to cause the closing force wellbore pressures to assist in a seal against the drill pipe, kelly or BHA from the wellbore pressure. The inside diameter of a stripper rubber element is considerably smaller than the outside diameter of the drill pipe or diameter of the kelly. In this way the stretching force applied around the drill string provides a positive seal.
Wellbore pressure applies a closing force on the cone shaped element and provides the self actuating seal. The greater the well bore pressure, the greater the closing force pressing the stripper rubber against the drill string or kelly. In this way no hydraulic pressure is required to activate a seal in low or high pressure regimes. In low pressure or no pressure scenario’s, the predominate seal, with stretching force from the element itself, is safe and reliable.
A misunderstanding that seems to persist is that wellbore pressure in low or high pressure environments creates a seal. Or that wellbore pressure only maintains a seal. Neither is correct.

16. Negative Impact to Stripper Rubber Elements
Kelly condition is critical.
Surface condition- check wear pattern on corners
Bent Kelly’s
Before picking up the new kelly, check the kelly bushing. The rollers, pins, or bearings may need replacing to return the drive assembly to like new status. Check the bushing body for journal area wear ,and body spreading. A loose fitting drive unit can badly damage a new kelly on the first well drilled. Remember to lubricate kelly drive surfaces.
Check wear pattern on the corners of the kelly.
The major cause for kelly wear is the rounding off or sharpening of the drive corners. This rate of wear is a function of the clearance fit between the kelly and the rollers in the kelly bushing.
The wear is usually caused by rig to stack misalignment, and/or an improper kelly drive roller fit.

17. Alignment Rig to Stack Alignment is critical Check Daily
Suspect to excessive element usage
Stack alignment is critical to the performance and life of the rotating drilling head bearings and stripper rubber. Check alignment by lowering the kelly until kelly bushing engages in the rotating drilling head. The kelly drive bushing should go into the drive bushing freely without having to force the kelly sideways. If the kelly drive bushing does not freely engage into the drive bushing of the rotating drilling head, then BOP stack and rig rotary should be properly aligned.
Check kelly by running your hands up it full length for sharpness.
Most stripper rubber elements used in the oil and gas industry are designed with a durometer hardness. The palm of your hand is approximately a 45 durometer. Your sneaker soles are a 60 durometer. If you feel that the palm of your hand could be cut or damaged by running it over the surface that the elastomers will travel. Then simply the elastomer will be damaged also in the same fashion.

18. Other Negative Impacts
Drill pipe identification grooves
Pitting and abrasion on drill pipe
Tong and slip die damage
Some hardbanding
Mills and bits
As higher pressure operations are extended the condition of drill pipe against which the seal is being made becomes more important. The seal life may vary widely for different pipe condition. The following practices will extend the life of the seal when operating in high pressure environments.
Maintain proper rig to stack alignment.
Inspect drill pipe regularly and clean up all tong marks and sharp edges.
Use low tapered tool joints on both box and pin ends (18 degrees)
Lubricate exterior surface of drill pipe and tool joint before stripping into the well.
Avoid use of tool joints with rough hard-banding surfaces and identification grooves cut into the tool joints.

19. Other Negative Impacts
Extreme cold
Extreme heat
Age
Sun light
Avoid tripping out of the well with pressures higher than required for the underbalanced needs…. element life increases rapidly as pressure decreases.
Inspect the seal at regular intervals, and change when significant wear is noticed. Operating the rotating head to the point of seal failure is not a good drilling practice. Frequency of the inspections should be based on pressure and the number of tool joints tripped in or out of the well.
Store elements that are not in use in a warm area. (boiler or doghouse) Elastomers become very brittle in extremely cold climates. They should be sufficiently warmed up prior to drill pipe being started in the element. .

20. Low Pressure Rotating Head
TT96-90
Gas and Air Drilling

21. Medium Pressure RDH Pressure to 700 psi Single or Dual Element
Lower Mounting Spools from 7 1/16” 2000 psi to 13 5/8” psi.
Outlet Flanges are 7 1/16”-2000/3000 psi
Grant - Smith

22. CALL FOR SIZES AVAILABLE
High Pressure MODEL 7000
Williams model 7000 is also designed to handle today’s most demanding underbalanced drilling requirements.
It is available in explosion proof and offshore models and comes with a side outlet flange. This unit is also equipped with a captive space vent for purging the system in sour gas applications.
DUAL ROTATING STRIPPER RUBBERS
Are designed to automatically seal tighter as pressures increase. The bottom rubber wears first, leaving the top rubber in newer condition for added safety.
WATER COOLED SEALS
Maximize the operating life of the bearing assembly.
POSITIVE OIL LUBRICATION
provides continuous flushing to keep debris out of te bearings and seals and maintains lubrication up to
2300 psi.
HYDRAULIC
OPERATED CLAMP
Provides a continuous closing force to compensate for operating stress.
For use on rigs with
top drives or Kellys
CALL FOR SIZES AVAILABLE

23. MODEL 7000 COMPONENTS REMOTE MODULAR POWER UNIT REMOTE MONITORING
U.S. Patent No.5,662,181
“Rotating Blowout Preventer”
REMOTE MODULAR POWER UNIT
REMOTE MONITORING
CONTROL CONSOLE
MODEL 7000 EXPLODED
CUT-AWAY VIEW
MODEL 7000 ROTATING
CONTROL HEAD

24. Rotating Head Schematics
Single Element
Dual Element

25. Hydraulic Oiler Lubricator/ And cooling System
Main Components
Hydraulic Oiler Lubricator/ And cooling System
Heavy Duty Rotating Drilling Head
Operation of the hydraulic unit is automatic. The high pressure system will increase or decrease hydraulic pressure when the well bore pressure increases or decreases. The low pressure system continuously circulates oil through the bearings. The hydraulic reservoir levels should be checked daily.

26. Contains large heavy duty tapered roller bearings
Bearing Assembly
Contains large heavy duty tapered roller bearings
Bearing Chamber sealed with low pressure seals against atmospheric pressure
Separate high pressure seal assembly to contain wellbore pressure
Oil contiously circulates through bearing assembly to lubricate and cool bearings and seals.
Separate lubricator system for high pressure seal assembly
Rotating test pressures of 1500 psi.
If necassary the drilling head can be changed by removing 3 quick release line to the bearing assembly and the high pressure seal assembly, unbolt the lower clamp and remove the bearing assembly in minutes.

27. Drive Assembly and Stripper Rubber
Elastomers available for oil, gas or geothermal drilling
Available in single or dual element systems
Combination one piece drive assembly and stripper rubber

28. KELLY DRIVERS • Available to fit all Kelly sizes and shapes
Designed with vertical bolts or
snap ring
Supplied with each complete
rotating control head
Steel or poly inserts available
Available for all models

29. MODEL 8000/9000 STRIPPER RUBBERS
• Standard
Heavy duty
Oil resistant
Stripper rubber usage is determined by the operating pressures, Kelly and drill pipe conditions and stack alignment.

30. MODEL 9200 GEOTHERMAL STRIPPER RUBBERS
(2)
(1)
• Drill collar (1)
Drill pipe (2)
Stripper rubber usage is determined by the operating pressures, Kelly and drill pipe conditions and stack alignment.

31. 7000 SERIES STRIPPER RUBBERS
Model 7100 Stripper Rubbers
• Heavy duty
Stripper rubber usage is determined by the operating pressures, Kelly and drill pipe conditions and stack alignment.
Model 7000 Stripper Rubbers
• Heavy duty
• Oil resistant

32. CASING STRIPPER RUBBERS
• Used to strip casing in the well
• Seals tight against bowl gasket using quick-lock clamp
• Assures diversion of mud and gas through
the flowline outlet
• Available for any size casing up to 13 3/8"
• Assures safety of rig personnel
Available for all models

33. LOGGING ADAPTER • Makes logging faster and easier
• Seals tight against bowl gasket using quick
lock clamp
• Features 7" - 9 5/8" rounded threaded collar to
receive logging lubricator
Available for all models

34. SPACER SPOOLS • Constructed of casing and flanges
• For models 8000 and 9000 series only
• Permits height to be changed to desired length
Used under rotating head to raise flowline
outlet to proper height
Available in all sizes
Specify flange series and height when ordering
TO ONLY BE USED ABOVE ANNULAR BOP

35. FLOWLINE FLANGES • Used to connect flowline to Rotating Head
• 7 1/16" w / swages from 6" - 12"
• 11" w / swages from 6" - 12"
Available for all models

36. PIPE WIPER HOLDER • Holds dual split or single pipe wiper rubbers
Keeps drill pipe clean
• Keeps drilling mud in the hole
• Saves mud and clean up time
• Rubber can be installed or removed
at any time
• Welds to all sizes of drilling nipples
Available for all models

37. OILER - LUBRICATOR • Operates from the rig’s air supply
• Supplies constant flow of filtered oil to
bearings and seals
• Insures long life of bearings and seals
• Supplied with each complete rotating
control head
• Available for models 8000, 9000 and
9200 only

38. DRILLING NIPPLE • Used to trip without bearing assembly
• Seals tight against bowl gasket using
quick-lock clamp
• Helps contain drilling mud while tripping
• Can be extended or cut to desired length
Available for all models

39. SNUBBING ADAPTER • Used to nipple-up the snubbing unit
• Permits snubbing without removal of
the rotating control head bowl
• Used for models 7000,7100 and IP1000
7 1/16” flange connection

40. BLANKED FLANGES Available in all sizes for all models
Specify size and series when ordering

41. Available for all models
TEST PLUG
Used to test the drill stack
Available for all models

42. RBOP - Oil Tools International
Developed by SealTech, Oryx Energy, Clayton Williams and Exxon
Designed for use in High GOR wells, Wells With H2S and High Pressure Wells.
TT96-93
Drilling Fluid Description

43. Wellhead Pressure Control
Active pressure unit
Multiple pressure settings
Simple quick packer change
2000 psi static pressure
11” ID capabilities

45. RBOP Schematic

46. Wellhead Pressure Control
Quick-Change
Packer Assembly
Kelly Drive
Assembly
Inner Packer
Outer Packer
Bearing
Hydraulic Fluid Inlet
Surge
Bottle
Seal
Outlet Flange
Bottom Flange

48. Wellhead Pressure Control
Simple quick packer change
Redundant element sealing
11” ID capabilities

49. Multiple pressure
settings
Rig floor operation

50. RBOP Closing Unit

51. Shaffer Rotating Blow-Out Preventer
Notes
2,500 psi rotating - 5,000 psi static

52. Drilling Fluid Description
Shaffer PCWD
TT96-93
Drilling Fluid Description

53. Passing a Tool Joint

54. Techcorp 3000

55. Inner Replaceable Element

56. TESCO DOUBLE ANNULAR Not a rotating preventer
Uses two small modified Shafer packers
Used like a rotating preventor

57. On of the two packers in the TESCO double annular packer discarded after use. Note the wear on the upper outside of the rubber finders. There is steel inside the fingers. Thisis essentially small Shaffer spherical annular

58. Rotating Heads and Rotating Blow Our Preventers SUMMARY

59. Rotating Drilling Heads Low - High Pressure Systems
Hydraulic Activated Systems
Not API certified as a blowout preventer
Sealability is electronically hydraulically actuated as a function of wellbore pressure
Shop serviced bearing assembly
Mechanical Interface
Systems
Not API certified as a blowout preventer
Stretch-interface seal maintained, assisted with wellbore pressure
Wellsite replaceable bearing assembly
Bearing assemblies and stripper rubber elements must operate and resist heavy upward thrust caused by wellbore pressures. Therefore oil lubricator systems must maintain a constant flow of oil through the bearing to lubricate and cool the bearing assemblies. This is also true of R.B.O.P.‘s. Some systems also cool their bearings with water or antifreeze. A hydraulic unit or power unit contains both the oil cooling and lubricating reservoirs, circulating pumps, and controls.
Hydraulic and manual operated clamps at the top of the rotating drilling head allows the bearings or stripper rubber assemblies to be removed quickly. The assemblies are lowered into place through the rotary table by riding on the last joint of drill pipe when the drill string is run in the hole.

60. Hydraulic Lubricator Systems
Hydraulic Active
System
Seal is hydraulically actuated as a function of wellbore pressure and lubricates the bearing
Usually a common oil reservoir cools bearing
Mechanical Interface System
Seal is activated by well pressure
Circulating system for high pressure used to lubricate and cool bearing -does not activate elements

61. Rotating Drilling Heads High Pressure Systems
Hydraulic Activated Systems
Pressure to activate is controlled by sensor or manually.
Seal is totally controllable.
Mechanical Interface
Systems
Seal is always active and increases with increasing well pressure.
“No pressure” seal is function of stretch fit.

62. END