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

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 1937. 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.

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.

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..

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

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

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

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.

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

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.

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.

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

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

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.

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.

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.

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 60-90 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.

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.

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. .

Low Pressure Rotating Head TT96-90 Gas and Air Drilling

Medium Pressure RDH Pressure to 700 psi Single or Dual Element Lower Mounting Spools from 7 1/16” 2000 psi to 13 5/8”- 5000 psi. Outlet Flanges are 7 1/16”-2000/3000 psi Grant - Smith

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

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

Rotating Head Schematics Single Element Dual Element

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.

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.

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

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

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.

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.

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

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

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

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

FLOWLINE FLANGES • Used to connect flowline to Rotating Head • 7 1/16" - 3000 - w / swages from 6" - 12" • 11" - 3000 - w / swages from 6" - 12" Available for all models

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

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

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

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

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

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

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

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

RBOP Schematic

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

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

Multiple pressure settings Rig floor operation

RBOP Closing Unit

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

Drilling Fluid Description Shaffer PCWD TT96-93 Drilling Fluid Description

Passing a Tool Joint

Techcorp 3000

Inner Replaceable Element

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

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

Rotating Heads and Rotating Blow Our Preventers SUMMARY

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.

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

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.

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