Introduction to Protectors S c h l u m b e r g e r P r i v a t e
Protector Functions •
The Th e Pr Prot otec ecto torr ha hass fi five ve pr prim imar aryy fu func ncti tion ons: s: – Couples the torque developed in the motor to the intake via the protector shaft. – Prevents entry of well fluid into the motor. – Provides pressure equalization. – Houses the bearing to carry the down thrust developed by the pump(s). – Provides a reservoir for the thermal expansion of the motor’s oil
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Protector Functions •
The Th e Pr Prot otec ecto torr ha hass fi five ve pr prim imar aryy fu func ncti tion ons: s: – Couples the torque developed in the motor to the intake via the protector shaft. – Prevents entry of well fluid into the motor. – Provides pressure equalization. – Houses the bearing to carry the down thrust developed by the pump(s). – Provides a reservoir for the thermal expansion of the motor’s oil
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Protector Types •
•
Lab abyyrinth - uses the di difffere ren nce in in sp speci ciffic gravity of the well fluid and the motor oil to keep them apart even though they are in direct contact Pos osiitive Seal – de dessigne ned d to phy hyssica callly separate the well fluid and motor oil – Elastomer bag – Metal bellows
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Protector Components Bearing Shaft Seal
Bag Chamber
Thrust Bearing Filter
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Labyrinth Type Protectors •
Protector oil specific gravity is .85
•
As long as well bore SG is heavier, labyrinth path works to isolate motor fluid from well bore
•
Labyrinth type protectors not recommended to be installed in a deviated or cycling well – Ineffective in well bore deviations > 55 degrees – Excessive cycling reduces protector ability to isolate fluids
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Intake
Protector
LABYRINTH TYPE PROTECTOR
HOW DOES IT WORK EXCESSIVE START STOP STARTING STOPPING STOPING OCCURS
Once well fluid enters motor it’s only a Motor matter of time before it burns
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Labyrinth Protectors - Limitations There will be cases where a labyrinth will simply not work. In cases where the well fluid is lighter gravity than the motor oil (i.e. about 0.85), the motor oil will go to the bottom of the chamber rather than the top causing the motor fluid to be displaced by well fluid pretty quickly.
Labyrinth Protectors - Limitations Labyrinth Protectors also will not work in horizontal or highly
deviated wells. The gravity separation design requires the unit to be mostly upright. This Protector can operate in some amount of deviation but the expansion volume is somewhat reduced.
Positive Seal Type Protectors •
Elastomer bag creates a positive barrier to well bore
•
Bag expands and contracts to meet motor demand
•
Check value opens at 3-5 psi to release pressures inside bag.
•
Elastomer must be selected to match well temperature and fluid properties
•
Works in vertical or deviated wells
•
Should never be rerun
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Positive Seal Protector LSBPB
Protector
(Labyrinth Series Bag Parallel Bag) 3–5 PSI
How does it work ?
START STOP
Bags Contracts due to getting less oil inside
Torn or leak (Could be seal failure)
MOTOR GETS BURNED
Temperature increase decrease
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Positive Seal Protectors – Limitations The positive seal Protector offers a great deal of flexibility and a nd is useful in a wide variety of applications. One area where care needs to be taken with this type of Protecto r is with harsh well chemicals as may be experienced with a treatment program. prog ram.
As with any oil field elastomer, care must be taken to ensure that the rubber will not be damaged by anything it will encounter in the well.
Positive Seal Protectors – Limitations The positive seal Protector offers a great deal of flexibility and a nd is useful in a wide variety of applications. One area where care needs to be taken with this type of Protecto r is with harsh well chemicals as may be experienced with a treatment program. prog ram.
As with any oil field elastomer, care must be taken to ensure that the rubber will not be damaged by anything it will encounter in the well.
Protector Elastomer Selection
REDA Elastomer Application Guidelines Temp. Limit (Deg F)*
Neoprene Nitrile 250
Carboxy-Nitrile 275
HSN 300
Viton 350
Aflas 400
2 4 4 3 4
1 1 1 3 2
Relative Chemical Resistance Properties Water/Oil Hydrogen Sulfide Amines Polar Chemicals Carbon Dioxide
1 1 3 4 2
1 3 3 4 2
1 1 3 1-2 2
*Temperature Limit above indicates maximum operating temperature for the specific REDA compound. An elastomeric component will operate at a temperature higher than the well ambient temperature depending on its location in the equipment. Contact REDA for specific application assistance.
1 = Excellent long term resistance (very low swell/maintains very high physical properties) 2 = Good long term resistance (moderate swell/maintains high physical properties) 3 = Fair - depends upon exposure time and temperature (good short term resistance) 4 = Poor - no resistance even in short term
Protector Function #2 Another function of the Protector is to absorb the thrust generated by the the genera ted by pump. It can either be upthrust or downthrust downthrust,, depending on the pumping conditions.
Upthrust bearing Thrust Runner Downthrust bearing
Protector Function #2 The thrust bearing works on hydrodynamic lubrication principle.
The runner
carrying the thrust forces is riding on a hydrodynamic oil film created by the relative motion between the runner and the bearing. Reaction Force
There are three types of bearing Reda offers.
Upthrust bearing
Standard bearing bearing – Babbitt (lead based)
Thrust Runner
HL Bronze bearing - (9000 LBS – 540 series, 60 HZ) HL bearing – Polymer coated tilting pad bearing
(12000 LBS – 540 series, 60 HZ)
Downthrust bearing
Protector Function #3 One other function which the Protector carries out is transmission of the motor torque to the pump since it is physically located between the two. Although this may seem a little trivial, in the selection process we need to be certain that the Protector shaft is capable of delivering the full torque required without exceeding its yield strength which could result in a broken shaft.
Modular Protectors – Naming Convention •
•
• •
Modular protectors are a combination of several protector types – “L” type (LLabyrinth) – “B” type (Elastomer Bag) – “M” type (M Metal Bellows) Which are combined in … – “S” (series) – adds redundancy – “P” (parallel) – adds capacity HL designates “high load” thrust bearing Example: LSMPM has a labyrinth chamber in series with two bellows in parallel
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Modular Protectors
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LSLSL
LSBPB
BPBSL
The Modular Protector The Modular Protectors are available in: 400 Series (4.00 "), 540 Series (5.13 ") and
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562 Series (5.62 ").
Both the 540 and 562 series have the same top and bottom flange and can either be run on a 540 o r 562 motor without adapters.
The 400 Series is designed to be run on the 456 Series motor without an adapter.
400
540
562
Modular Protector Application - Chamber Configuration Key: 1 = Excellent
2 = Good
3 = Fair
4 = Poor
Application Type BHT < 250 F 250 F < BHT < 300 F
L LSL LSLSL B LSB LSBPB BSL BSBSL BPBSL LSBSB 2 2 1 2 1 1 1 1 1 2 3 3 2 4 4 4 4 4 4 3
(A) G < 0.82
2
2
1
3
2
2
2
2
2
2
4 4
4 4
4 2
3 3
1 2
1 2
1 2
1 2
1 2
1 1
4 4 2
4 4 2
4 4 1
3 3 2
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
3 3 2
HP < 150 HP > 150
2 2
2 2
1 1
4 4
1 4
1 1
1 4
1 4
1 1
2 3
Aggressive Well Fluids (B)
2
2
1
4
1
1
4
4
4
2
Intermittent Operation Deviated Well Miscible Well Fluid HP < 50
(A) Applicability improves with correct elastomers for higher temp. service, usually Aflas for seal elastomers, o-rings, & bags.
(B) Those that deteriorate specific elastomers used. Assumes use of standard materials for configurations listed. Use normal guidelines for application of high load bearings and ferritic housings.
REDA Protector Bottomhole Temperature Limits
200 °F
400/456 540/562
Modular Standard
400/456 540/562
Modular AFLAS
225 °F
250 °F
275 °F
300 °F
Protector Load Ratings vs. Temperature for REDA 2 Oil
400 Series Protector 10,000 Hi Ex Bearing
7,500
) f B L ( d a o L
5,000
Bronze Bearing
2,500
0 0
50
100
150
200
Bottom Hole Temp (°F) 60 Hz and Above
50 Hz
250
300
Protector Load Ratings vs. Temperature for REDA 2 Oil 540 Series Protector
15,000
Hi Ex Bearing
12,500
) f B 10,000 L ( d a o L
Bronze Bearing
7,500
5,000 0
50
100
150
200
Bottom Hole Temp (°F) 60 Hz and Above
50 Hz
250
300
Protector Load Rating vs. Temperature for REDA 2 Oil 562 Series Protector
20,000 Hi Ex Bearing
15,000
) f B L ( 10,000 d a o L 5,000
0 0
50
100
150
200
Bottom Hole Temp (°F) 60 Hz and Above
50 Hz
250
300
Protector Power Consumption for REDA 2 Oil Est. Power Consumed at 200 °F BHT
4 3
562 Series
r e w2 o p e s r o 1 H
0
540 Series 400 Series 0
2000
4000
6000
8000
Thrust Load in Pounds
10000
12000
14000
Advanced Protector •
• •
Addresses protector performance in severe well conditions and is available in three different configurations – High Temp > 350 degF BHT – High H2S and chemical resistant – Abrasive resistant Protects protector head (shaft seals and bearings) against abrasion and solids Improves protector shaft stability even in benign environments
Both HT and H2S configurations are using metal bellows to replace the rubber bags S c h l u m b e r g e r P r i v a t e
Advanced Protector Features • Use of ceramic bearing to reduce vibration. • Use dual bearing in protector head for better radial stability • New abrasive resistant head design including: • Sand shroud to protect mechanical seal. • Dual ceramic bearing • Elevated mechanical shaft seal • Drain holes to prevent sand / solids from accumulating in the protector head • High pressure check valve. • Pre-shimmed protector shaft
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Vulcan System Features • Offered only as a complete system • Rated to 425 degF Bottom hole temperature and 475 degF internal oil temperature • System tested up to 500 DegF BHT under full motor loading • Using metal bellows for motor oil compensation • Using metal bellows shaft seals • Using Khemraz HighTemp. O-rings • Motor and protector using special oil having high viscosity at high temperature • Protector components (shaft, housing, thrust bearing, ….) materials selected to minimize stresses caused by different thermal expansion coefficients
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Metal Bellows •
• • • •
Replace HSN/AFLAS bags with Inconel 625 LCF bellows – to provide positive barrier to H2S and gas – to provide better performance in high temperature Welded Inconel bellows rated to 100,000 full cycles Bellow capacity = .5 Gallons Special spread sheet developed for bellow sizing Can be reused during protector repair
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Current Design
New Design
Metal Bellows Shaft Seals •
Replace HSN/AFLAS bellows with Inconel 625 bellows to provide positive barrier to H2S.
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Sour and Chemical Resistant Protector • •
• •
Rated to 30 % (Maximum) H2S Reduce dependence on elastomers by using metal bellows for motor oil compensation. The metal bellow is an effective H2S barrier Using metal bellows shaft seals Protector components (shaft, housing, thrust bearing, ….) materials selected to minimize chemical attack
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Technical Feature Summary Feature
High Temp
Chemical
Abrasion
Replacement of elastomer bag with metal bellows
X
X
Use of metal bellows shaft seal
X
X
Use of high load thrust bearings with no coppe copperr parts
X
X
Dual head bearings for shaft seal support
X
X
X
Ceramic journal bearing for abrasion resistance
X
X
X
Solid shield over head bearings for abrasion resistance
X
X
X
Use of high pressure relief valve to ensure valve closure
X
X
X
Factory shimmed shaft to eliminate eliminate field field shimming shimming
X
X
X
Use special High Temperature Oil
X
Use of Chemraz O- rings
X
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Key Technical Issues Current Protectors High Temp
High temperature is causing elastomer material to become brittle.
Advanced Protector Metal bellow is not affected by temperature.
H2S
Rubber bag is not an effective H2S or gas barrier
Metal bellow is an effective H2S and gas barrier
Chemical
Elastomer bag will be affected by some chemical attacks
Inconel metal bellow will handle most chemicals
Vibration
Shaft seals will leak if shaft is not properly supported
Dual bearing ceramic support for the shaft reduces vibration
Solids
solids accumulation in protector head will damage shaft seal
New head design prevents solid accumulation and protects seals
Abrasion
Shaft bushing subject to wear
Ceramic shaft bearing reduce abrasive wear
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Specifications H2S Content
0 - 30 %
Operating Temperature
130 F to 475 F with up to 0% H2S °
°
130 F to 300 F with up to 5% H2S °
°
100 F to 250 F with up to 30% H2S °
Well bore Temperature
°
50 F to 425 F with up to 0% H2S °
°
50 F to 250 F with up to 5% H2S °
°
50 F to 200 F with up to 30% H2S °
°
Surface Temperature
-40 to 120 F
Construction
Compatible with current product line
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