29 4 10MB
COURSE CONTENTS I - GENERAL OVERVIEW . II - SUCKER PUMPING SYSTEM COMPONENTS .
III – SYSTEM DESIGN AND SELECTION.
IV – SURVEILLANCE AND PERFORMANCE EVALUATION .
V – MAIN PROBLEMS & TROUBLESHOOTING .
VI - PUMPING UNIT INSPECTION AND MAINTENANCE PROCEDURES .
VII – SUCKER ROD CARE AND HANDLING PROCEDURES .
I – GENERAL OVERVIEW
ARTIFICIAL LIFT APPLICATIONS : • Required Req ired when hen reservoir reser oir pressure press re is no longer sufficient to lift fluids to surface due to : ¾Reservoir depletion . ¾Water p production . A/L APPLICATION CONDITIONS :
•
Enhancing the production of well .
•
Producing a dead
well .
a weak flowing
Well System y Tubing head pressure p
Separator pressure
Outflow Static pres. = P Pressure at formation
Pwf
Inflow
Distance from well
Artificial Lift P surf
Ph
The well: Flows if Pwf > Ph + Psurf Dies if Ph + Psurf ≥ Pwf
Pwf
Pr
Artificial Lift Decreases BHP and Increases Rate
Boottomholle pressurre
Tubing curve #1 PR BHP1
Tubing curve #2 w/artificial lift
BHP2 BHP2 < BHP1 q 2 > q1 q1
q2 Flow rate
AOF
Artificial Lift Market R i Region
N AL wells No ll
N b off W Number Wells ll
AL as a % off ttotal t l wells
N America
546,820
568,681
96 %
132 346 132,346
138 610 138,610
95 %
Far East
152,502
156,207
98 %
S America
50,316
53,291
98 %
Middle East
7,548 ,
15,645 ,
48 %
Africa
5,303
10,885
49 %
W Europe E
3 258 3,258
4 851 4,851
67 %
S Pacific
1,075
1,380
78 %
TOTAL
899168
949550
+// 95 %
E Europe (excluding some FSU countries)
Source - World Oil 2005
Artificial Lift distribution worldwide Total Other ESP
14%
7%
G Lift Gas
8%
Rod Pump
71%
FACTORS MANAGING A/L SELECTION : •
WELL PRODUCTIVITY , PI .
•
WELL DEPTH .
•
WELL GEOMETRY ( VERTICAL OR DEVIATED ) .
•
WELL LOCATION ( OFFSHORE – ONSHORE ) .
•
FLUID PROPERTIES ( GOR , API , VISCOSITY , CORROSIVE FLUIDS , SAND , TEMP. ) .
•
RIG AVAILABILITY .
•
POWER SUPPLY .
•
MATERIALS AND SPARE PARTS AVAILABILITY .
•
FIELD LOCATION ( LOGISTICAL ISSUE ) .
•
ECONOMIC FACTOR ( CAPEX & OPEX ) .
•
PERSONNEL EXPERIENCE .
S R PUMPING SYSTEM ADVANTAGES : S.R. •
SIMPLE ( CAN RUN EVEN WITH POOR DESIGN AND PERFORMANCE ) .
•
APPLICABLE FOR REMOTE AREAS ( IN MOST PROBLEMS NO NEED FOR WORKOVER RIG ).
•
STRONG DRAW-DOWN CAPABILITIES .
•
POSITIVE DISPLACEMENT ( NO EFFECT FOR BACK PRESSURE ON WELL PRODUCTION ) .
•
ECONOMIC WHEREVER APPLICABLE .
•
ABILITY FOR AUTOMATION AND TELEMETRY CONTROL .
•
PRODUCTION FLEXIBILITY TO ACCOMMODATE UNFORESEEN WELL CHANGES ( FROM 30 BFPD TO 4500 BFPD ) .
•
PRODUCE AND EVALUATE UNKNOWN WELL PERFORMANCE .
S.R. PUMPING SYSTEM DISADVANTAGES : •
PRODUCTION LIMITATIONS WITH DEPTH .
•
FREQUENT MECHANICAL FAILURES AND INTENSIVE MAINTENANCE & FOLLOW UP .
•
ENVIRONMENTAL IMPACTS ( POLLUTION AND OIL SPILLS ) .
•
POOR WELL CONTROL IN CASE OF UNFORESEEN BEHAVIOR .
•
POTENTIAL TUBING WEAR AND FREQUENT COMPLETION STRING REPLACEMENT .
•
NONECONOMIC IN CASE OF MIS-APPLICATION ( DEEP WELLS , HIGHLY DEVIATED WELLS , HIGH GOR WELLS , HIGH SAND PRODUCTION WELLS , etc ……………… ) .
Production Vs. Depth For Rod Pumping 4500 4000 3500 3000 BFPD
2500 2000 1500 1000 500 0 1
2
3
4
5
6 7 8 9 10 11 12 13 14 15 Fluid Lift, ft X1000
BEST APPLICATION CONDITION FOR S.R. PUMPING SYSTEM :
•
VERTICAL WELL .
•
SHALLOW TO MODERATE WELLS ( > +/- 5000 FT ) .
•
LOW GOR WELL ( < 700 SCF/STB ) .
•
LIGHT TO SEMI VISCOUS FLUIDS ( < 500 CP ) .
•
ONSHORE WELLS .
•
LOW SAND PRODUCTION WELLS .
•
NON CORROSIVE FLUIDS .
•
LOW W/C PRODUCTION .
•
DEAD WELLS ( SAFETY IMPACTS ) .
II - PUMPING SYSTEM COMPONENTS
١٥
S.R. PUMPING SYSTEM
S.R. PUMPING SYSTEM COMPONENTS
1 5
4 1 - PUMPING UNIT . 2 - SUCKER ROD STRING . 3 - DOWNHOLE PUMP . 4- PUMPING HEAD ASSEMBLY . 5 - PRIME MOVERS . 6 - SAFETY AND PROTECTION SYSTEM. SYSTEM
2
3 ١٧
1 – PUMPING ( SURFACE ) UNITS : PUMPING UNIT IS USED TO CONVERT THE HIGH ROTARY SPEED TO LOW RECIPROCATING MOTION ( GEAR RATIO FROM 30 TO 1 ) .
MAIN FUNCTIONS : •
PROVIDE RECIPROCATION .
•
CARRY WELL LOADS .
•
PROVIDE THE REQUIRED TORQUE .
PUMPING UNIT TYPES :
•
API BEAM UNITS .
• SPECIAL BEAM UNITS . • NON BEAM UNITS .
١٩
API BEAM UNITS
٢٠
BEAM PUMPING UNIT COMPONENTS
A - CONVENTIONAL UNIT , REAR BASE MOUNTED UNIT
CLASS I LEVER
FULCRUM FORCE LOAD
ADVANTAGES : •
THE MOST COMMON TYPE WORLDWIDE .
•
LOWER COST ( RELATIVE TO OTHER TYPES WITH THE SAME UNIT SIZE ) .
•
NO COMPLETE DISMANTLING WHILE WORKOVER OPERATIONS .
•
BI-DIRECTIONAL ROTATION INCREASES GEAR BOX RUNNING LIFE .
DISADVANTAGES : •
NEED MORE SPACE AREA AND CONCRETE BASES .
•
LOWER TORQUE AND LOAD CAPABILITIES FOR SAME CONDITIONS COMPARED WITH M-II ( ALMOST 2/3 OF MII ) .
•
MORE POWER CONSUMPTION .
•
HIGH AMP. FLUCTUATIONS EVEN IN CASE OF GOOD BALANCE COMPARED WITH MII .
B - FRONT MOUNTED BASE UNIT ( MARK II )
CLASS III LEVER
FULCRUM FORCE LOAD
ADVANTAGES : •
HIGHER TORQUE CAPABILITIES ( USED MAINLY FOR DEEP , HIGH LOAD WELLS ) .
•
MORE
•
COMPACT GEOMETRY , SMALLER FOOTPRINT .
•
LOWER HP CONSUMPTION & EASIER BALANCE .
•
BETTER SMOOTHEN AMP. CONSUMPTION ALONG THE PUMPING SYCLE .
LOAD CAPACITY ( FASTER IN DOWN STROKE AND SLOWER IN UPSTROKE ) .
DISADVANTAGES : •
NEED COMPLETE DISMANTLING WHILE W/O OPERATIONS .
•
HIGHER COST COMPARED WITH CONVENTIONAL .
•
UNI DIRECTIONAL ROTATION ( CCW ) . UNI-DIRECTIONAL
•
MORE SENSITIVE FOR FLUID POUNDING AND VISCOUS FLUID AT HIGH SPEEDS .
•
HEAVIER
C/W NEEDED
( TO OVERCOME THE NEGATIVE STRUCTURAL UN-BALANCE )
C- ENHANCED GEOMETRY UNIT (PHASED CRANK )
IT IS A CONVENTIONAL UNIT GEOMETRY BUT WITH CRANK PHASE ANGLE ( FROM 9 TO 15 DEGREE ) .
•
IT HAS THE SAME CHARACTERISTICS OF THE CONVENTIONAL UNIT BUT WITH BETTER TORQUE AND LOAD CAPABILITIES ( UNI-DIRECTIONAL ROTATION O O ( CW C ) ..
COMMON TYPES ARE : •
MAXIMIZER II ( MAX II ) , MANUFACTURED BY AMERICAN INTERNATIONAL .
•
REVERSE MARK ( RM ) , MANUFACTURED BY LUFKIN .
•
HRS TYPE ( CHINESE ) .
D - AIR BALANCED UNIT
THE COUNTER BALANCE IS PROVIDED WITH AIR COMPRESSOR NOT COUNTER WIGHT ( MANUFACTURED BY LUFKIN ONLY ) . ADVANTAGES : •
LIGHT WEIGHT ( CAN BE USED FOR OFFSHORE APPLICATIONS ) .
•
ULTRA LONG STROKE BEAM UNITS ( COULD REACH 240 240” ) .
•
USED FOR DEEP WELLS , ULTRA-HEAVY LOADS , HIGH PRODUCTION WELLS .
•
IT HAS THE GREATEST UNIT SIZES ( COULD REACH 2560,000 in-Ib ) .
•
EASY TO BE BALANCED , BI-DIRECTIONAL .
DISADVANTAGES : •
VERY EXPENSIVE COMPARED WITH OTHER TYPES .
•
AIR COMPRESSOR AND ACCESSORIES REQUIRE FREQUENT MAINTENANCE .
•
POTENTIAL HAZARDS IF SOME GASES INTER THE AIR COMPRESSOR .
•
LESS COMMON TYPE .
SPECIAL BEAM UNITS
٣٢
•
LOW PROFILE UNIT ( WHEN HEIGHTS ARE CRITICAL) .
•
ROAD-RUNNER ROAD RUNNER UNIT ( TRAILER MOUNTED FOR TEMPORARY / REMOTE APPLICATIONS ) .
•
BEAM BALANCED UNIT ( CHURCHILL ) NO C/W , ( FOR VERY SHALLOW LOW LOADS WELLS ) .
Low-Profile Pumping Unit - Strap jack
• Low clearance applications such as under sprinkler systems • Urban, scenic, and visually sensitive areas • Higher cost than conventional units
ROAD-RUNNER UNIT :
TRAILER MOUNTED FOR TEMPORARY / REMOTE APPLICATIONS
Beam Balanced Unit
• Smaller sizes for shallow and/or low volume wells (usually 57 or 80 gear reducer sizes are largest available) • Counterweights are loaded on rear of walking beam.
NON BEAM UNITS
٣٧
THERE ARE OTHER LATE TECHNOLOGY FOR PUMPING UNIT TYPES WITHOUT BEAM THAT HAVE BEEN INTRODUCED IN THE LATE YEARS OF 20 th. CENTURY .
•
ROTAFLEX ( LONG STROKE UNIT ) , FROM WEATHEREFORD .
•
MORLIFT UNIT , FROM NOV .
•
CORLIFT UNIT , FROM NOV .
Ultra Long Stroke Pumping Unit R t fl ™ ( Max. Rotaflex™ M SL.= SL 366” ) . • Longer strokes provide higher pump compression ratios to prevent gas lock problems • Fewer cycles and reversals on pumps and rods • Production rates to 6,000 6 000 BPD • High system efficiency and cost effectiveness e ec e ess for o deep, troublesome, oub eso e, a and d high-volume wells • Alternative to: – Electric submersible pumps – Hydraulic jet pumps – Large conventional units
Corlift™ 18-120 • High performance, artificial lift unit for oil and gas applications; direct mounted, lower profile . • Maximum Load Rating: 18,000 lbs • Variable V i bl stroke t k llength: th 0-120" 0 120" . • Variable stroke speed: 0-6 spm (depending on rod load) . • Powered by a slightly modified National Oilwell standard hydraulic skid . • Benefits include low setup costs, minimal ground disturbance, easy installation and long stroke advantages advantages. • Applications include oil and gas well production sites,, remote areas where p pump jack set up is expensive, and dewatering gas wells.
THE API UNIT DESCRIPTION IS :
Unit type
MII
Gear reducer torque q X1000 in-lb
912 D
Structural load rating X 100 lb
365
Max. stroke length g
144
C
640 D
305
120
A
1280 D
470
240
THE SMALLEST PUMP JACK SIZE IS :
C 6.4 D – 32 - 16 THE LARGEST PUMP JACK SIZE IS :
A 2560 D – 470 - 250
Standard API Sizes API Reducer Torque R ti Ratings X 1000, 1000 in-lb. i lb
API Structural R ti Ratings X 100, 100 lb. lb
80
API Standard Stroke L Lengths, th in. i 48
114
143
54
160
173
64
228
200
74
320
213
86
456
246
100
640
256
120
912
305
144
1280
365
168
1824
427
192
470
216
2560
240
2 – SUCKER RODS : SUCKER ROD IS USED TO TRANSMIT THE MOTION FROM THE PUMPING UNIT TO THE D.H.P IT IS MANUFACTURED AT A STANDARD DIMENSIONS , LENGTHS : 25 FT AND 30FT ( +/- 2 in ) :
A – API SUCKER ROD GRADES :
GRAD E
K
C
D
TENSILE STRENGTH , in Ib in-Ib
APPLICATION
85000 100000
Low loads , corrosive environment
90000 115000
115000 140000
Medium loads , non-corrosive environment
Medium to Heavy loads – some types for corrosive (D-90 ) , others for non-corrosive ( D-78 )
ROD SIZE , in
ROD WT. Ib/ft
TUBING SIZE , in
COUPLING SIZE , in
FULL
SLIM
1/2
0.726
2 1/16
--
1
5/8
1 135 1.135
2 1/16
1 1/2
1 1/4
3/4
1.634
2 3/8
1 5/8
1 1/2
7/8
2 224 2.224
2 7/8
1 13/16
1 5/8
1
2.904
3 1/2
2 3/16
2
1 1/8
3.676
3 1/2
2 3/8
--
B – NON API SUCKER ROD GRADES : THESE TYPES ARE : 1 ULTRA HIGH TENSILE STRENGTH GRADES . 1. 2.
FIBERGLASS RODS .
3.
HOLLOW RODS .
4. COILED RODS . 5. ROTOR RODS .
GRADE N-97 , S-88 T 66 T-66 UPCO 50
TENSILE STRENGTH , in-Ib
APPLICATION
140000 150000 140000-150000
EXTRA HEAVY LOADS CONDITIONS
FIBERGLASS TYPE :
VERY LIGHT WEIGHT S.R. REDUCES LOADS & TORQUE TO PROVIDE MORE PRODUCTION CAPABILITIES IN DEEP WELLS , CORROSION RESISTANT , BUT IT HAS SPACING PROBLEM ( STRETCH +/- 4 TIMES STEEL RODS ) , DIFFICULT FISHING AND SHORT PUMP LIFE PROBLEMS DUE TO EXCESSIVE WEAR , MOREOVER BOTTOM-HOLE TEMP. BELOW 200 F .
C – OTHER ROD ACCESSORIES: ROD COUPLINGS ; COUPLINGS ARE USED TO CONNECT S S.R. R •
CLASS ( T ) COUPLINGS ,,,, LOW CORROSION EROSION RESISTANCE .
•
CLASS ( S ) COUPLINGS ,,,, MEDIUM CORROSION EROSION RESISTANCE
•
CLASS ( T ) HR COUPLINGS ,,,, HIGH CORROSION EROSION RESISTANCE .
•
ANTI-FRICTION COUPLINGS ,,,,,, FOR SEVERE FRICTION AND DRAG FORCES .
PONY RODS : SHORTER RODS ARE USED TO COMPLETE THE TOTAL LENGTH OF ROD STRING WHILE PUMP SETTING . COMMON LENGTHS : 2 ft , 4 ft , 6 ft , 8 ft , 10 ft .
SINKER BARS ( WEIGHT BARS ) : IT PROVIDES EXTRA WIGHT ABOVE THE PUMP TO :
1 KEEP THE ROD STRING IN TENSION AT DOWN-STROKE 1. DOWN STROKE 2.
CENTRALIZE ROD FOR BETTER PLUNGER FUNCTIONING .
3.
AVOID ROD BUCKLING ( ONE OF MAJOR PROBLEMS ????? ) .
COMMON SIZES 1 1/8” THROUGH 1.5’’ WITH 3/4’’ OR 7/8’’ PIN END . •
CARBON STEEL TYPE .
•
ALLOY STEEL TYPE .
STABILIZER BARS : IT IS USED ABOVE THE PUMP VALVE ROD TO CREATE STIFFNESS , PROTECT VALVE ROD GUIDE AND EXTEND PUMP RUNNING LIFE .
ROD GUIDES AND CENTRALIZERS : THEY ARE USED TO BETTER CENTRALIZE ROD STRING INSIDE THE TBG. IN ORDER TO MINIMIZE ROD / TBG. MUTUAL WEAR . • FIBERGLASS OR TEFLON TYPE ( MOLDED OR RETRIVALBE ) . • WHEEL OR ROLLER TYPE ( FOR CROOKED HOLES ) .
POLISHED ROD ; IT IS POLISHED TO PROVIDE A GOOD SEAL AGAINST THE STUFFING BOX TO AVOID OIL LEAKS . SIZES : 1 1/8" , 1 1/4" , 1 1/2" ,,,,,,,,,,,,,, LENGTH 8 FT THROUGH 35 FT.
POLISHED ROD MATERIALS; • PISTON STEEL , moderate to heavy loads , non corrosion . • SPREY METAL , moderate to heavy loads , good corrosion / abrasion . • HIGH STRENGTH , extra heavy loads , good corrosion / abrasion . NOTE : POLISHED ROD EXTENSION CAN BE USED TO UNSET THE PUMP FOR KILLING THE WELL BEFORE DISMANTLING THE WELL HEAD .
ROD SYMBOL :
SIZE
1/2
5/8
3/4
7/8
1
1 1/8
SYMBOL
4
5
6
7
8
9
EXAMPLES : ROD CONFIGURATION 87 , IT MEANS TAPER 1" AND 7/8" . ROD CONFIGURATION 65 , IT MEANS TAPER 3/4" AND 5/8" . ROD CONFIGURATION 97 , IT MEANS TAPER 1 1/8" , 1" AND 7/8" .
3 – DOWN HOLE PUMP ( DHP ) : MAIN TYPES OF DHP ARE :
A- TUBING PUMP ( TP ) IT HAS TWO MAIN TYPES : i - THE PUMP BARREL RUN WITH COMPLETION WHILE PLUNGER , WHILE PLUNGER AND S.V. RUN WITH S.R. ( WHEN PLUNGER SIZE IS SMALLER THAN TUBING SIZE ,, 2.75 2 75 “ pump inside i id 3.5” 3 5” TUBING ) NOTE : IN SOME MODELS THE S.V. RUNS WITH BARREL . ii - THE COMPLETE PUMP RUNS WITH COMPLETION AND SUCKER ROD ENGAGED THE PUMP WITH ON/OFF TOOL ( WHEN PLUNGER SIZE IS SMALLER THAN TUBING SIZE ,, 3.75” 3 75” PUMP WITH 3.5” 3 5” TUBING ) .
ADVANTAGES : •
LARGE PRODUCTION VOLUMES ( COULD REACH 3000 BFPD ) .
•
SAND PRODUCTION WELLS ( TUBULAR PUMPA-PUMP OF HF ) .
DISADVANTAGES : •
WORKOVER RIG TO REPLACE DAMAGED BARREL .
•
WORKOVER RIG TO REPLACE UNFISHABLE S.V.
•
VERY EXPENSIVE .
•
USED FOR SHALLOW WELLS ONLY ( < 3000 FT ) .
B- CASING PUMP ( COMPLETION LESS PUMP ) : LARGE SIZE ( 5 ½” ) PUMP IS RUN AND SET INSIDE THE CASING , BUT THIS TYPE IS UNFAVORABLE DUE TO : •
POSSIBLE CASING DAMAGE .
•
ROD FISHING CONSTRAINS .
•
POOR RES. MONITORING .
•
NO WELL CONTROL IN CASE OF EMERGENCY .
C – ROD PUMPS ( COMMONLY USED ) :
TYPE
BOTTOM HOLD DOWN
SYMBOL
DESCRIPTION
FEATURES
RWB
THIN WALL , STATIONARY BARREL
HIGHER RATE , BUT STICKING PROBLEMS
RHT
HEAVY WALL TRAVELING BARREL
CLEANING C G SO SOLIDS S AND DEBRIS
RWT
THIN WALL TRAVELING BARREL
,,,, ,,,,
HEAVY WALL BARREL
LOWER RATE , RESISTS STICKING , HIGH DIFFERENTIAL PRESSURE
THIN WALL BARREL
HIGHER RATE , RESISTS STICKING , LOW DIFFERENTIAL PRESSURE
RHA
TOP HOLD DOWN
RWA
D H P COMPONENTS : D.H.P.
•
BARREL ( HEAVY & THIN WALL ).
•
PLUNGER ( SOFT-PACKED SOFT PACKED , METAL SOLID , METAL GROOVED ) .
•
TRAVELING VALVE & STANDING VALVE ( TV & SV ) .
•
SETTING ASSEMBLY ( CUP TYPE , MECHANICAL SET , ANCHOR PUMP SET ) .
•
VALVE ROD , CONNECT PLUNGER WITH S S.R. R ( 3/4 3/4" , 7/8 7/8" , 1 1/16" 1/16 ) .
•
OTHER ACCESSORIES .
PUMP NOMENCLATURE :
30- 225 RHAC 24- 6 - 2
PUMP ANCHOR : IT IS A TECHNIQUE BY WHICH THE PUMP CAN BE SET AT ANY DEPTH ( IT CAN BE EQUIPPED WITH THE PUMP AS TOP OR BOTTOM HOLD-DOWN ) .
MAIN TYPES : •
HARBISON-FISHER ROTATION TYPE ( NOT EFFECTIVE , WEAK ) .
•
WEATHERFROD STROKE SETTING TYPE , ( GOOD PERFORMANCE ) .
MAIN APPLICATIONS : •
PRODUCE O UC TUBING U GC CRACKED C WELL ( DELAY THE NEED FOR O WORKOVER O O ).
•
PRODUCING LOST PUMP WELLS ( DELAY THE NEED FOR WORKOVER ) .
•
PRODUCE WELLS WITHOUT SEATING NIPPLES WITHOUT WORKOVER JOB , ( SPECIALLY IN REMOTE AREAS OR UNAVAILABLE RIGS ) .
+
4 – PUMPING HEAD ASSEMBLY WITH NORMAL TUBING HANGER . •
PUMPING ADAPTOR .
•
BOP .
•
STUFFING BOX .
•
PUMPING TEE .
•
FLOW LINE AND CASING CONNECTIONS .
•
PRESSURE & TEMPERATURE GAUGES .
PUMPING ASSEMBLY WITH KTH HANGER .
5 – PRIME MOVERS : THE PUMPING UNIT CAN BE DRIVEN BY : i – ELECTRICAL MOTORS : ARE MANUFACTURED WITH 4 TORQUE MODES FOR ALL OF THE FOLLOWING TYPES : •
NEMA C TYPE ,,, 5% SLIP FACTOR , 250 % STARTING TORQUE CAPACITY .
•
NEMA D TYPE ,,, 5 – 13% 3% S SLIP FACTOR C O , 270 0%S STARTING G TORQUE O QU CAPACITY C C .
•
ULTRA HIGH SLIP TYPE ,,, 30 – 40% SLIP FACTOR , 270 % STARTING TORQUE CAPACITY . ( THIS TYPE RECUES STARTING LOAD AND TORQUE LIKE SOFT STARTER , BUT ITS COST IS VERY HIGH ) .
NOTE : VARIABLE SPEED DRIVE ( VSD ) CAN BE USED FOR SOFT STARTING AND ADAPTING UNIT SPEED WITHOUT CHANGING SHEAVES .
ii – DIESEL ENGINES .
iii – GAS ENGINES .
Electric Motor Slip : When the load on an electric motor increases, the motor slows down (slips) as it develops more torque to handle the increased load load. “Slip” is the difference between motor speed at no load and the motor speed at full load as a percentage of no load speed :
(No Load RPM - Full Load RPM) / No Load RPM F example, For l if a 1200 RPM motor t operates t att 1104 RPM under d ffullll lload: d Slip = 100% = 8%
(1200 - 1104) /1200
٦٢
6 – SAFETY AND PROTECTION SYSTEM :
•
PRESSURE SWITCH ( SECURE THE WELL AGAINST HIGHER AND LOWER WELL HEAD PRESSURES ) .
•
VIBRATION O SWITCH S C (S SECURE CU THE U UNIT AGAINST G S S STRONG O G VIBRATION O ).
•
STUFFING BOX AND POLISHED ROD TO AVOID OIL SPILLS
•
ELECTRICAL MOTOR UNDERLOAD AND OVERLOAD PROTECTION .
•
PUMP-OFF CONTROLLER CAN BE USED FOR FULL SYSTEM CONTROL
.
٦٣
III - S.R. SYSTEM DESIGN AND SELECTION
Required Information • • • •
Targett Production T P d ti (oil ( il and d water) t ) Pump p seating g depth p . Current well completion Dynamic fluid level or pump intake pressure . • Well Head pressure . • Fluid p properties p ( sp.gr p g , GOR , ….etc. ) .
Beam Pumping p g System y Design g • Subsurface pump – Size – Type – Materials
• Rod string – Rod string configuration – Grade – Coupling size
• Surface pumping unit – Size – Type
• Prime mover
SYSTEM DESIGN CONSIDERATIONS ( Rule of Thumb ) :•
ALWAYS MAXIMIZE SL AND MINIMIZE SPM ( IF THE AVAILABLE PUMPING UNIT SIZE CAN ACCOMMODATE THE TORQUE ) .
•
MAXIMIZE PUMP SUBMEGENCE .
•
UNIT STRUCTURAL LOADING SHOULD NOT EXCEED 75 % OF ITS RATING ( TO ACCOMMODATE THE FUTURE CONSTRAINS ) .
•
GEARBOX TORQUE LOADING SHOULD NOT EXCEED 75 % OF ITS RATING ( TO ACCOMMODATE THE FUTURE CONSTRAINS ) .
•
SUCKER ROD STRING LOADING SHOULD NOT EXCEED 80 % OF ITS RATING ( TO ACCOMMODATE THE FUTURE CONSTRAINS ) .
•
PLUNGER MINIMUM LENGTH IS 3 FT ,,, INCREASE 1 FT EACH 1000 FT OF WELL DEPTH .
•
PLUNGER FIT RANGED FROM 0.003 0.003” TO 0.007 0.007” ( INCREASED WITH VISCOSITY , DECREASED WITH DEPTH ) .
•
PUMP BARREL LENGTH SHOULD NOT BE LESS THAN 2 TIMES THE MAX. SL .
•
POLISHED LENGTH SHOULD NOT BE LESS THAN 3 TIMES THE MAX. SL .
•
ALWAYS INSTALL SAFETY CLAMP .
•
KEEP FROM 2 TO 3 FT DISTANCE BETWEEN THE CARRIER BAR AND STUFFING BOX .
•
KEEP BOTH TUBING AND ROD STRING WITHIN SUFFICIENT TENSION .
CONTINUED • Design production volume = slightly below target production volume to keep from starving the pump. • Max lift (p (pressure)) should be based on minimum fluid levels at the maximum system pumping rate. • System y power should be based on max pumping g rate at max pressure plus extra for start-up torque requirements. Electric is preferred if available. • Slower in viscous oil to allow rod fall on the down-stroke • Faster (SPM > 8) in sandy fluids to keep sand in solution and moving. • Pump speed should be slow enough to allow the compression chamber to completely fill . • The multiplication of SL & SPM should not exceed 1440 . • Follow the rule ( longer , deeper & slower ) whenever possible . • Use high strength and tapered rod string for deep wells , to reduce rod loading .
CONTINUED • for gassy wells use smaller pump size , deepen plunger to improve compression p ratio :
Compression ratio = total stroke volume / un-swept volume . • for heavy oil wells , minimize speed , maximize pump size , use slim couplings or COROD to avoid piston effect . • for sandy wells , maximize pump size and pumping speed to keep sand in suspension . • for unknown well performance , start the well with the minimum parameters available , then re-optimize after close monitoring .
Casing , Tubing and Pump Sizes Casing size
Tubing size , max
Sucker rod size , max
2 7/8
1 1/2
5/8 slim hole coupling
3 1/2
2 1/16
3/4 slim hole coupling
4
2 3/8
4 1/2
2 7/8
5
RW Insert pump , max
RH Insert pump , max
TH Tubing pump , max
Over size Tubing pump , max
1 1/4
-----
1 1/2
2
7/8 slim hole coupling
1 1/2
1 1/4
1 3/4
2 1/4
1 slim hole coupling
2
1 3/4
2 1/4
2 3/4
1 1/8
2 1/2
2 1/4
2 3/4
3 3/4
2 7/8
5 1/2 3 1/2 6 5/8 7
4 3/4 4 1/2
7 5/8
1 1/8
3 1/4
2 3/4
3 3/4 5 3/4
SINKER BAR WEIGHT CALCULATION
THERE ARE SEVERAL DESIGN SOFT WARE PROGRAMS IN THE MARKET LIKE :
•
Purchasable soft wares . 1 . S ROD . 2 . DAIG$$ . 3 . ECHOPUMP C O U . 4 . RODSTAR .
,
Free soft wares . 1 . LOADCALC. 2 . QROD .
SOME DESIGN EXAMPLES USING AND LOADCALA
QROD
PROGRAMS
IV – SURVEILLANCE AND PERFORMANCE EVALUATION
S R SYSTEM SURVEILLANCE IS VERY ESSENTIAL TO : S.R.
•
EVALUATE AND OPTIMIZE THE WELL PERFORMANCE .
•
IMPROVE THE OVERALL SYSTEM EFFICIENCY .
•
REDUCE THE DOWN TIME AND OPERATING COST .
1 – PERIODICAL WELL SURVEILLANCE : •
DAILY WELL MONITORING PLAN . CONDITION MONITORING ITEM
WELL HEAD PRESSURE
WELL HEAD TEMPRATURE
NORMAL
HIGH
LOW
OK
PRODUCTION IMPROVEMENT OR FLOW LINE RESTRICTION
SUBSURFACE PUMP SUBSURFACE PUMP PROBLEM OR FLOW LINE LEAK
OK
PRODUCTION IMPROVEMENT OR IMPROVEMENT OR W/C INCREASED
SUBSURFACE PUMP PROBLEM OR PROBLEM OR RESRVOIR DECLINE
DAILY CHECK‐UP FOR PUMPING UNIT ( LOOK & LISTEN ) , NOISE , V BELT CONDITION , ALIGNMENT , STUFFING BOX , GAS VENTING , OIL SAMPLING …….. etc.
٧٦
•
MONTHLY WELL MONITORING PLAN .
CONDITION MONITORING ITEM NORMAL
HIGH
LOW
PRODUCTION TEST
OK
RESERVOIR IMPROVEMENT
SUB‐SURFACE PUMP PROBLEM OR RESERVOIR DECLINE RESERVOIR DECLINE
DYNAMOMETER TEST
OK
THE PROBLEM WILL BE IDENTIFIED BASED ON DYNO‐CARD ANALYSIS
OK
SUB‐SURFACE PUMP PROBLEM OR PROBLEM OR RESERVOIR IMPROVEMENT
D F L MEASUREMENT
RESERVOIR DECLINE ٧٧
DYNAMOMETER TEST ANALYSIS : DYNAMOMETER IS AN INSTRUMENT BY WHICH THE S.R. LOAD VARIATIONS ARE MEASURED ALONG THE ROD PUMP CYCLE ( UPSTROKE & DOWN STROKE ) .
DYNAMOMETER TEST PROVIDES THE FOLLOWING VALUABLE DATA : •
ACTUAL ROD LOADS ( PEAK AND MIN. ) .
•
ROD STRESS CALCULATIONS ( AS % OF GOODMAN ) .
•
ACTUAL GEAR BOX TORQUE LOADING .
•
PUMPING UNIT BALANCE CONDITION .
•
T.V. & S.V. PERFORMANCE .
•
D.H.P. PERFORMANCE ( PUMP CARD ) .
•
PUMP INTAKE PRESSURE .
•
PUMP DISPLACEMENT .
•
ACTUAL PUMP FILLAGE .
•
EFFECTIVE STROKE LENGTH ( S.L. ) .
•
PUMP STROKE PER MIN. (SPM ) .
PUMPING MECHANISM :
1 – UP-STROKE UP STROKE ( SUCTION ) : • P2 < P3 & P1 . • T.V. T V CLOSES , S S.V. V OPENS .
2 – DOWN-STROKE ( COMPRESSION ) : • P2 > P3 & P1 . • T.V. T V OPENS , S S.V. V CLOSES
SUBSURFACE PUMP MECHANISM VIDEO
TYPICAL PUMP CARDS
SOME ACTUAL DYNAMOMETER RUNS ANALYSIS
2 – REAL TIME WELL SURVEILLANCE : LOCAL SURVEILLANCE : BY USING ROD PUMP ( SAM ) CONTROLLER AND READ ALL DATA LOCALLY AT WELL SITE , 24 HRs./ DAY , 7 DAYS/ WEEK . TELEMETRY SURVEILLANCE : BY USING TELEMETRY SYSTEM TO TRANSFER ALL WELL SIGNALS ( PRESS. , TEMP. , ROD PUMP CONTROLLER DATA , MOTOR DATA ) TO CONTROL ROOM FOR FULL ACCESSIBILITY 24 HRs./ DAY , 7 DAYS/ WEEK .
VERY IMPORTANT NOTE : WELL SITE CHECK-UP WILL REMAIN VERY ESSENTIALS EVEN WITH TELEMETRY SURVEILLANCE .
ROD PUMP CONTROLLER ( RPC ) ADVANTAGES : •
STOPS THE WELL AT CERTAIN PUMP FILLAGE TO MINIMIZE FLUID POUNDING .
•
REDUCES MECHANICAL FAILURES AND IMPROVES THE SYSTEM OVERALL EFFICIENCY .
•
PROJECT THE DAILY WELL PRODUCTION RATE .
•
FULL WELL CONTROL AGAINST HIGH/LOW LOADS , HIGH/LOW RPM , HIGH/LOW AMP. , etc………..
•
FULL HISTORICAL DATA FOR RUNNING TIME , LOADS , DYNO-CARD , etc…..
•
REAL TIME SYSTEM PERFORMANCE MONITORING AND EVALUATION ( PUMPING UNIT , RODS , D.H.P. , etc……
•
POWER SAVING .
ROD PUMP CONTROLLER DISADVANTAGES : •
RESTART TIME & CONSEQUENT STROKES ACCURACY ( PRODUCTION LOSSES IF NOT ACCURATE ) .
•
MECHANICAL AND ELECTRICAL FAULTS , LOGISTICAL ISSUES TO KEEP IT HEALTHY .
•
DIFFICULTY TO ADJUST PUMP FILLAGE IN GASSY WELLS ( EXPECTED PRODUCTION LOSSES ) .
•
POSSIBLE PUMP PLUGGING FOR SANDY , PARAFFINIC & ASPHALTIC WELLS .
•
SHORTENS ELECTRICAL GENERATOR RUN LIFE ( FULL/NO LOAD VARIATIONS ) .
•
SHORTENS ELECTRICAL MOTOR RUN LIFE ( START/STOP VARIATIONS ) .
•
DIFFICULT W/C AND D.F.L MONITORING .
•
POSSIBLE FLOW LINE PLUGGING ( OIL FREEZING IN STATIC CONDITION ) IN WINTER SEASON .
•
EXTRA HEAVY LOADS AND DRAG FORCES IF USED IN HIGHLY VISCOUS OIL .
VSD PUMP OFF CONTROLLER : IT IS THE LATEST VERSION OF PUMP OFF CONTROLLER TO AVOID MOST PROBLEMS OF THE OLD VERSION .
FEATURES / ADVANTAGES : •
CONTINUOUS ADJUSTING FOR THE SPM BASED ON PUMP FILLAGE .
•
CAN INCREASE THE UP-STROKE SPEED AND DECREASE DOWN-STROKE SPEED ( SEPARATELY ) .
•
USED IN HIGHLY VISCOSE WELLS WITHOUT EXTRA HEAVY LOADS OR ROD FLOATING .
•
NO SAND OR PARAFFIN PLUGGING .
•
NO MOTOR OR GENERATOR DAMAGE .
•
NO RESTART TIME OR CONSEQUENT STROKES PROBLEMS .
•
NO FLOW LINE PLUGGING .
•
ACCURATE W/C AND D.F.L MONITORING .
•
NO NEED TO ADJUST PUMP FILLAGE .
V – MAIN PROBLEMS O S & TROUBLESHOOTING O S OO G
Equipment Failure • Real Time Monitoring will lower failure frequencies and pre ent catastrophic fail prevent failure; re th thus sq quickly ickl pa paying ing for itself • E Early l Detection D t ti off Wear W or Corrosion C i Related R l t d Damage D Will Prevent More Expensive Repairs Due to Catastrophic Failure . • Inspect All Equipment When Pulled for Well service – Inspect p for Corrosion Damage, g , Wear , etc ….. This will help in minimizing the failure frequency . • Failure Analysis and Failure Tracking are the keys to determining corrective action to take.
S SURFACE C PROBLEMS O S
1 – GEARBOX OVERLOADING : THE GEARBOX IS OVERLOADED WHEN THE ACTUAL APPLIED TORQUE EXCEEDS THE GEAR BOX RATING , THIS MIGHT CREATE DAMAGE FOR GEAR BOX TEETH OR SHAFT ( DO NOT EXCEED +/- 75 % OF THE TORQUE RATING TO ACCOMMODATE FUTURE CONSTRAINS ) .
REASONS : • IMPROPER UNIT SIZE SELECTION FROM START-UP ( THE SELECTED UNIT CAN NOT HANDLE THE WELL LOADS ) . • UNIT UNBALANCE ( 90 % OF OVERLOADING IS DUE UNIT UNBALANCE ) . • SUDDEN CHANGE IN WELL CONDITION .
CORRECTIVE ACTIONS : • SELECT LARGER UNIT SIZE TO . • REBALANCE PUMPING UNIT . • RE –OPTIMIZE O THE PUMPING G PARAMETERS S TO O MEET THE SUDDEN S WELL CHANGE C G (S START WITH MINIMIZING THE SL ) .
Relative Gearbox Life VS loadingg 30 25
Life, yea ars
20 15 10 5 0 100 0% 100.0%
110.0% 110 0% 120 0% 120.0% Percent Overload
130 0% 130.0%
LOAD
LIFE
Fatigue Fractures-Normally Caused by Overloading
Destructive Pitting-Poor Lubrication or Overload
American Slow Speed Shaft-Design Defect
Crankshaft Failure and Resulting Catastrophic Unit Failure due to Shaft Deflection and to Sticking Pump
2 – PUMPING UNIT MISALIGNMENT : IT APPEARS AS : •
MOTOR AND GEAR BOX SHEAVES MISALIGNMENT WILL SHORTEN THE V BELTS RUN LIFE AND CONSUME MORE POWER .
•
PUMPING UNIT MISALIGNMENT AGAINST WELL HEAD WILL CREATE MORE FRICTION AT WELL HEAD BETWEEN POLISHED ROD AND STUFFING BOX , THEN W/H LEAK OR POLISHED FAILURE .
•
POOR LEVELING FOR THE GROUND BEFORE INSTALLATION CREATES POOR LAY OUT AND UNIT INSTABILITY .
•
PITMAN ARMS MISALIGNMENT WILL NOT EQUALLY DISTRIBUTE THE WELL LOADS ON BOTH SIDES , THIS COULD CREATE BEARING FAILURE OR WALKING BEAM TWISTING .
•
BRIDLE MISALIGNMENT WITH HORSE HEAD , WIRE CAN FALL AT ONE SIDE AND FURTHER DAMAGE CAN HAPPEN .
3 – CRANK PIN ( WREST PIN ) BEARING FAILURE OR STUCK & CRANK HOLE DAMAGE : THIS IS CONSIDERED THE WORST PROBLEM COULD HAPPEN FOR THE PUMPING UNIT THAT COULD LEAD TO EQUIPMENT COMPLETE LOSS , EXCESSIVE REPAIR COST AND LONG DOWN TIME .
FAILURE CAUSE : •
UNIT MISALIGNMENT .
•
POOR INSPECTION AND LACK OF LUBRICATION .
•
WRONG INSTALLATION .
•
UNIT OVERLOADING .
•
PIN NUT LOOSENING .
TROUBLESHOOTING : •
KEEP THE UNIT IN GOOD ALIGNMENT .
•
FOLLOW PROCEDURE WHILE INSTALLATION ( CLEAN HOLE WITHOUT CREASE , TIGHT THE NUT , PUT THE STOPPER LOCK ) .
•
INSPECT FOR NOISE , LOCK STOPPER , GREASE PERIODICALLY ( EVERY 6 MONTH ) .
•
AVOID UNIT OVERLOADING .
Broken Crank Pin Caused by Continuously Pounding Fluid
COMPLETE UNIT FAILURE DUE TO SEVERE MISALIGNMENT OR LOOSEN BOLTS
Resulting g Unit Catastrophic p Failure from Broken Crank Pin
4 - Wireline/Bridle Wi li /B idl Failures F il : Wear and/or Fatigue both External and Internal - from Abrasive Wear (External) and From Individual Wires Moving Relative to One Another (Internal) . FAILURE CAUSE :
• • •
Unit overloading . unit misalignment . C Corrosion i problems bl .
CORRECTIVE ACTION :
• • •
keep the unit within its normal load and good alignment . change in case of damage . Grease it in case of humid environment .
5 – UNIT UNBALANCE : OVER-BALANCE : C/W CREATES COUNTER BALANCE EFFECT EXCEEDS THE WELL LOADS ( DOWN-STROKE AMP. HIGHER THAN UP-STROKE ONE ) . FOR REBALANCE ,,, MOVE C/W INSIDE . UNDER-BALANCE : C/W CREATES COUNTER BALANCE EFFECT LESS THAN THE WELL LOADS ( UP-STROKE AMP. HIGHER THAN DOWN-STROKE ONE ) . FOR REBALANCE ,,, MOVE C/W INSIDE . BOTH OVER-BALANCE AND UNDER-BALANCE CONDITIONS CAUSE : •
MORE POWER CONSUMPTION .
•
SHORTEN PRIME MOVER RUN LIFE .
•
CAUSES GEAR BOX OVERLOADING .
D Down-Stroke St k
Up Stroke Up-Stroke
Load = Weight Rods + Weight of Fluid Load = Weight of Rods
CBE = Weight of Rods + 1/2 Weight of Fluid
Counterbalanced System A
A
100 lbs.
50 lbs.
150 lbs. Up-Stroke p
Counterbalanced System A
A
100 lbs.
50 lbs.
50 lbs. Down-Stroke
6 – POLISHED ROD FAILURE : POLISHED ROD FAILURE JUST BELOW THE CARRIER BAR REPRESENTS +/- 90 % OF FAILURES .
FAILURE CAUSE :
• • • • •
Tighten Rod clamp with over-torque ( creates excessive stresses ) . Unit misalignment g against g well head. Mishandling . Corrosion problems . Improper polished rod type selection .
CORRECTIVE CO C ACTION C O :
• • • • •
Never apply over-torque for Rod clamp ( use two clamps for deep wells and high loads ) . Better unit alignment . Never use pipe wrenches to tight or dismantle polished rod . Replace it in case of Corrosion . Use proper polished rod type .
7 – STUFFING BOX LEAK : Incase of stuffing box leaking , oil spilled out of the well creating pollution and environmental impacts and may lead to unsafe operations .
CAUSES :
• • • • • •
Poor greasing . Excessive tightening. polished rod or well head misalignment . corroded polished rod . F Free water t production d ti . High well head pressure .
CORRECTIVE ACTION :
• • • • •
keep proper and periodical greasing . never over-tight stuffing ff box . Replace corroded polished rod . keep well head and polished rod in good alignment . always keep high well head pressure and water production wells in close monitoring .
DOWNHOLE O O PROBLEMS O S
1 – FLUID POUNDING : PROBLEM NATURE : INCOMPLETE PUMP FILLAGE CREATES A HAMMERING EFFECT FOR S.R. & D.H.P. IN THE DOWN STROKE ( SEE ATTACHED SKETCH ) :
REASONS : • •
INSUFFICIENT PUMP INTAKE PRESSURE . PUMP INTAKE RESTRICTION .
FLUID POUNDING CAUSES SEVERE PROBLEMS LIKE : •
PUMPING UNIT BASE VIBRATION ( LOOSENS THE BOLTS ) .
•
GEAR BOX TEETH DAMAGE .
•
S.R. PREMATURE FATIGUE FAILURE .
•
ROD UNSCREW FROM BOTTOM .
•
D.H.P. FAILURE ( T.V. , VALVE ROD BREAK ) .
•
ROD BUCKLING AND EXCESSIVE TBG. WEAR .
FLUID POUNDING NATURE :
FLUID POUNDING TROUBLESHOOTING :
•
RE-OPTIMIZE THE PUMPING PARAMETERS ( S.L. , SPM & P.S. ) .
•
USE PUMP OFF CONTROLLER TO MATCH PUMPING RATE WITH THE ACTUAL WELL PRODUCTIVITY .
•
USE CHARGER VALVE ( SAND CHECK ) TO MINIMIZE THE EFFECT OF POUNDING .
•
CHECK PUMP INTAKE FOR RESTRICTION ( THIS COULD BE CONSIDERED IN CASE OF POUNDING AT HIGHER DYNAMIC LEVEL) .
•
INCREASE PUMP SUBMERGENCE IF POSSIBLE .
2 – GAS POUNDING AND GAS LOCK : PROBLEM NATURE : GAS SEPARATED AND ACCUMULATED INSIDE THE PUMP REDUCING THE VOLUMETRIC EFFICIENCY , IF IS NOT MINIMIZED IT WILL CREATE COMPLETE GAS LOCK . REASONS ARE : • •
HIGH GOR OR FOAMY FLUIDS . POOR GAS VENTING WHILE PRODUCTION .
GAS POUNDING CAUSES SEVERAL PROBLEMS LIKE : • •
REDUCING PUMP VOLUMETRIC EFF. COMPLETE PUMP OFF IN CASE OF GAS LOCK .
GAS POUNDING TROUBLESHOOTING : •
IMPROVE GAS VENTING THROUGH ANNULUS .
•
MINIMIZE PUMP SPACING TO IMPROVE THE PUMP COMPRESSION RATIO .
•
MAXIMIZE S.L. S L AND P P.S. S AND MINIMIZE SPM ( LONGER , LARGER , DEEPER AND SLOWER CONDITION ) .
•
INSTALL PUMP BELOW PERFORATIONS TO ALLOW FOR GRAVITY SEPARATION ( IN CASE OF SUFFICIENT RAT HOLE AND NO SAND PRODUCTION ) ,, THIS IS THE MOST EFFICIENT SOLUTION SO UTION .
•
INSTALL GAS ANCHOR ( SEPARATOR ) , SEE THE FOLLOWING SKETCH .
•
USE VSP ( VARIABLE SLIPPAGE PUMP ) .
Pump intake below perforation
GAS SEPARATOR
Variable slippage pump VSP
3 – SUCKER ROD FAILURE ( ROD PARTING ) .
A – TENSILE FAILURE : •
IT APPEARS AS A BOTTLE NECK SHAPE DUE TO ROD ELONGATION WHEN USING IMPROPER ROD TYPE OR CREATES EXCESSIVE TENSION TO FREE STUCK PUMP , ( ACTUAL APPLIED LOADS EXCEEDS THE ALLOWABLE LOADS ) .
TROUBLESHOOTING : •
BETTER ROD TYPE SELECTION DURING THE INITIAL DESIGN .
•
NEVER EXCEED THE ALLOWABLE ROD LOAD RATING DURING TRIALS TO FREE STUCK PUMP .
B – CORROSION FAILURE : •
THE ROD IS PARTED DUE TO AREA REDUCTION AS A RESULT OF CORROSION ( CHEMICAL REACTION BETWEEN STEEL AND CO2 , H2S OR ACID .
TROUBLESHOOTING : •
USE CORROSION RESISTANT ROD TYPE .
•
USE CORROSION INHIBITOR .
C – FATIGUE ( MECHANICAL ) FAILURE : It originates from a local increase in stress as small, progressive stress cracks that advance, upon each applied load, with the action of fluctuating or cyclic stresses to rupture, or final shear tear. SUCH TYPE IS CONSIDERED THE MOST COMMON TYPE WORLD WIDE .
REASONS : •
IMPROPER MAKE-UP
•
IMPROPER CARE AND HANDLING FOR SUCKER ROD .
•
SEVERE FLUID POUNDING .
•
EXCEED ROD ENDURANCE LIMIT .
•
MANUFACTURER DEFECTS .
•
USING OLD RODS WITHOUT INSPECTION .
•
PUMP TAGGING DOWN .
TROUBLESHOOTING : •
FOLLOW API CARE AND HANDLING PROCEDURE .
•
FOLLOW API MAKE MAKE-UP UP PROCEDURE ( USE TORQUE GAUGE ) .
•
RE-OPTIMIZE THE WELL PUMPING PARAMETERS TO MINIMIZE FLUID POUNDING .
•
NEVER EXCEED THE ENDURANCE LIMIT .
•
NEVER USE UN-INSPECTED RODS .
D - ROD COUPLING UNSCREW & COUPLING / PIN FAILURE :
IN SOME CASES , THE FAILURE OCCURRED AS COUPLING UNSCREW OR FAILURE
REASONS : •
OVER MAKE-UP TORQUE .
•
UNDER MAKE-UP TORQUE .
•
OLD DIRTY WORN THREAD COUPLINGS .
•
SEVERE FLUID POUNDING .
•
EXCESSIVE COUPLING WEAR .
TROUBLESHOOTING : •
ALWAYS MAKE-UP RODS WITH TORQUE GAUGE .
•
NEVER USE OLD DIRTY COUPLINGS .
•
RE-OPTIMIZE WELL PARAMETERS .
POOR HANDLING DURING OPERATIONS
E - ROD BUCKLING TENDENCY : BUCKLING TENDENCY HAPPENS DUE TO COMPRESSION LOADS IN THE DOWN S O STROKE ( THE ROD O SHOULD S O BE KEPT UNDER TENSION S O IN ALL CONDITIONS CO O S).
PROBLEMS RELATED TO BUCKLING : •
EXCESSIVE ROD AND TUBING WEAR .
•
SUCKER ROD FAILURE OR UNSCREW .
•
VALVE ROD AND VALVE ROD GUIDE DAMAGE .
REASONS : •
SEVERE FLUID POUNDING .
•
EXCESSIVE ROD SPEED ( EXCEEDS FREE FALL SPEED ) .
•
HEAVY VISCOUS OIL .
•
IMPROPER ROD STRING DESIGN .
•
PUMP TAGGING .
TROUBLESHOOTING : •
ELIMINATE POUNDING AND OPTIMIZE SPEED SPECIALLY IN HEAVY VISCOUS WELLS
•
USE SINKER & STABILIZER BARS TO CENTRALIZE RODS AND KEEP IN TENSION .
•
NEVER KEEP PUMP STRONGLY TAGGING DOWN .
4 - DOWN HOLE PUMP FAILURE : THE PUMP STOPS PRODUCTION DUE TO MECHANICAL DAMAGE , CORROSION DAMAGE OR PLUGGING .
REASONS : •
CORROSION ( IMPROPER MATERIAL SELECTION ) .
•
EXCESSIVE SAND ABRASION ( FOR PLUNGER , BARREL AND T.V. & S.V. ) .
•
SEVERE FLUID POUNDING .
•
SCALES , ASHPALTINE & PARAFFIN PLUGGING .
•
POOR REDRESSING IN WORKSHOP .
•
PUMP TAGGING DOWN .
TROUBLESHOOTING : •
PROPER MATERIAL AND SIZING SELECTION .
•
USE SAND FILTERS OR TUBULAR ( PUMPA-PUMP ) FOR HEAVY SAND PRODUCTION .
•
FOLLOW-UP API PROCEDURE FOR PUMP REPAIR .
•
USE CORROSION INHIBITOR ( IN CASE OF CORROSIVE FLUID ) .
•
APPLY REGULAR CHEMICAL TREATMENT .
•
NEVER KEEP THE PUMP SEVERELY TAGGING DOWN .
Downhole Equipment Failure WOW!!! How much force is necessary to do this damage? g Solids trapped b between the h barrel b l & the plunger also increase loads on th upstroke! the t k !
Downhole Equipment Failure
• Split traveling valve cage from f fl id fluid pound.
Downhole Equipment Failure
• Fractured nickelcarbide bid standing t di valve seat from fluid pound.
Downhole Equipment Failure Pump tagging • stress t fatigue f ti • Wear
5 – TUBING WEARS AND CRACKS : PROBLEM NATURE : •
LONGITUDINAL TBG. WEARS AND CRACKS APPEAR AS A RESULT OF MUTUAL FRICTION BETWEEN S.R. S R COUPLINGS AND TBG TBG.
•
COMMONLY EXISTS IN THE BOTTOM SECTION OF TBG. STRING ( +/- 90 % ) .
•
IT IS CONSIDERED AS ONE OF THE COMMON PROBLEMS OF S.R. SYSTEM WORLD-WIDE .
PROBLEM IMPACT : •
INCREASES WORKOVER FREQUENCY .
•
INCREASES OPERATING COST .
•
INCREASES MATERIALS CONSUMPTION
•
INCREASES PRODUCTION LOSSES .
Non--anchored Tubing Non No buckling Neutral point
Buckling
Downstroke
Upstroke
Breathing
“F”
TBG CRACKS REASONS : TBG. •
ROD BUCKLING ( HIGH SPEED , INSUFFECIENT SINKER BAR , FLUID POUNDING , PUMP TAGGING DOWN ) .
•
TUBING BUCKLING ( UNANCHORED TUBING OR APPLY INSUFFICIENT TENSION ) .
•
USE SUCKER ROD SYSTEM IN CROOKED HOLES .
•
FREE WATER PRODUCTION ( REPRESENTS THE MAIN CRITICAL REASON SINCE IT INCREASES MUTUAL FRICTION BETWEEN RODS AND TUBING ) .
•
PRESENCE OF CORROSIVE FLUIDS ( ENHANCES THE EROSION CORROSION EFFECT ) .
HOW TO MINIMIZE TUBING WEARS AND CRACKS : •
ELIMINATE ALL REASONS OF ROD BUCKLING .
•
APPLY PROPER TENSION FOR TBG. STRING ( YOU MAY USE KTH HANGER ) .
•
USE ROD GUIDES OR WHEEL GUIDES TO CENTRALIZE RODS INSIDE TUBING .
•
ELIMINATE WATER SOURCE ( APPLY WSO JOBS IF POSSIBLE ) .
•
USE ANTI-FRICTION COUPLINGS AND BLAST JOINTS IN THE HOT SPOTS .
•
APPLY CORROSION INHIBITION PROGRAMS .
•
MINIMIZE PUMPING SPEED .
VI – PUMPING UNIT INSPECTION AND MAINTENANCE PROCEDURES
1 - PUMPING UNIT INSPECTION
WIRE LINE ASSEMBLY • • • • • •
Look for corrosion Check for broken wires Check for kinks Measure size of wire rope Check condition of carrier bar L k att alignment Look li t with ith wellll h head d
FOUNDATION • CHECK LEVEL IN BOTH DIRECTIONS . • LOOK FOR WASHOUT AROUND THE EDGES . • LOOK FOR MOVEMENT AS THE UNIT RUNS . • CHECK TIE DOWN BOLTS FOR TIGHTNESS . • CHECK CONDITION OF CONCRETE SURFACE . • LOOK FOR CRACKS .
STRUCTURE AND FASTENERS • Listen for unusual noises such as creaks, pops, squeals, etc. • Check Ch k ffor cracks k • Look for bent or twisted parts • Look L k ffor signs i off prior i repairs i • Look for excessive corrosion • Check Ch k ffor lloose jjoints i – rust stains i • Check for broken or missing bolts • Check condition of ladder
STRUCTURAL BEARING ASSEMBLIES • Vi Visually ll iinspectt h housings, i caps and d retainers t i ffor cracks k and/or signs of movement (rust stains) • Look for metal shavings, shavings pieces of bearings bearings, seals seals, snap rings, etc. on the ground beneath the bearing assemblies • Listen for popping, popping creaking or groaning noises • Collect sample of old grease from the relief fitting and look for metal particles in grease as well as other contamination
STRUCTURAL BEARING ASSEMBLIES - CONTINUED • Check crank p pin to crank jjoint for signs g of p poor fit • Check for signs of endplay in crank pin bearings • Check for signs of misalignment of walking beam and equalizer/pitman assembly.
Surface Equipment Failures
CRANK ARMS AND COUNTER WEIGHTS • Visually inspect the slow speed shaft’s fit in the bore of the crank especially if clamp on crank • Look for cracks in crank around slow speed bore and around counter weights . • Look for cracks between crank pin holes . • Visually inspect counter weights for cracks . • Check weight bolts .
GEAR REDUCER • Check for cracks in the gear case, bearing carriers, etc. • Inspect the slow speed shaft and seals . • Visually inspect gear oil, look for signs of contamination . • Inspect the slow speed gear . • Inspect the intermediate assy. • Inspect high speed gear .
GEAR REDUCER - CONTINUED • Look for signs of loose bearings (in the bearing carriers) . • Inspect the brake assembly and adjust brake if required . • Check condition of belts . • Check the gear reducer sheave . • Check prime mover sheave .
Gear Reducer
Proper Wiper Operation
Adequate q Lubrication Adequate dequate Lubrication is necessary for long reducer life.
Corrective Pitting-Normal in New Reducers
Sh Sheaves and dB Belts lt • Horsepower Losses Result from Worn Out Sheaves or if Belt Tension is Inadequate – Replace Sheaves if Worn or Damaged and Replace Belts if Cracked or Frayed . • Sheave Alignment is Critical to Belt and Sheave Life . • Belts Found on the Ground Can Signify the y of a Serious Down-hole Problem or Possibility Sheave Misalignment Either of Which Should be Investigated and Corrected Before Putting Unit Back On-Line
2 - Pumping Unit Maintenance schedules h d l The following is the minimum recommended procedures for a good PM Program:
Pumping Unit Maintenance Daily y 1.
LOOK - Really look at the unit on a daily basis to observe any changes in the unit’s alignment, pitman to crank spacing, wire-line tracking, and any thing else that has changed in the past 24 hours which may indicate a problem beginning to manifest itself. itself These changes should be reported and/or corrected as soon as possible or at least checked out by a qualified service representative for confirmation of further action to be taken.
2.
LISTEN – Really listen for any noises such as gearbox or structural bearing rumbling, popping, clicking, squalling, squeaking or any other noises that may indicate the beginning of a bigger problem. problem Any changes in the sound of a pumping should be reported and further investigated to prevent a more in depth problem or possible catastrophic failure.
3.
APPLY – the brake slowly but firmly to assure it is in good working condition. Should the brake need adjustment or is not working properly, it should be reported and/or corrected immediately.
Pumping Unit Maintenance Monthly 1. Continue with the LOOK, LISTEN, and APPLY. 2. Check the oil level in the gear reducer to ensure it is at the proper operational level . 3 Review all bolts condition visually . 3.
Pumping Unit Maintenance E Every Si Six M Months th 1.
Continue with the LOOK, LISTEN, and APPLY.
2.
Check the significant bolting for proper bolt tightness. Additionally, this should also be done two weeks after any unit is set and put into operation.
3.
Take a sample of the reducer oil. after the unit has been shut down for a time sufficient enough to allow for oil to drain . I - Take a typical sample, preferably in a glass . II - Check the sample for possible contamination by sludge, dirt, water, metal or any other foreign material and compare the collected sample with i h new oil il condition di i . III - Report any problems or leakage.
4.
Grease the structural bearing g assemblies and report any detected problems such as metal flakes in relieved grease.
5. Issue a complete pumping unit inspection sheet to the designated Company representative for his determination of further work required.
NB : N.B. • Preventative maintenance, by definition, is decisive counteraction to keep any piece of equipment from premature failure. p
• The PM inspection and tasks should be documented and the reports should be kept in the well file.
VII – SUCKER S C ROD O CARE C & HANDLING G PROCEDURES OC S ( According to API RP 11 BR )
R d care & h Rod handling dli procedure d cycle 1. Storage practices . 2. Loading & unloading practices . 3. Running & pulling practices .
Storage procedure 1.
Store separately according to grade , size & condition .
2 2.
Use wooden racks with proper spacing ( avoid buckling ) .
3.
Put wooden spacer between each layer .
4.
Clean , grease and use coupling & thread protectors ( for condition II rods ) .
5.
For packaged rods , use supports under crosswise binder .
6.
Protect rods with suitable coating or paint ( in case of corrosive environment or weather humidity ) . Al Always P Prevent t rods d from f metal t l to t metal t l contact t t.
7 7.
Correct
wrong
packaged
unpackaged
Loading & unloading practices 1.
Never use fork to lift the unpackaged rods ( to avoid rod scratching and pending due to excessive flexing ) .
2.
Load and unload unpackaged rods by hand ( single to prevent bowing ) .
3.
Transfer rods to well location on flat dick trailer .
4.
Never use pickups to load rods even if few rods ( to avoid rod scratching and pending due to excessive flexing ) .
5.
It is preferable to use rod boxes with same dimensions of storage racks .
6. 7 7.
Protect rods with suitable coating or paint ( in case of corrosive environment ) . Never place rods on ground at well site ( rig walk is recommended )).
8.
Never put handling tools on top of rods nor run over by trucks
Correct
wrong
Running & pulling practices 1.
Never lay down rods to ground in double ( tailed into the derrick in suitable hangers ) , rods can be lain down in single .
2.
Use proper handling tools and inspect them for damage periodically .
3.
Never use pipe wrenches for make-up .
4 4.
Make M k sure th thatt pin i th thread d and d coupling li are clean l and d in i good d condition diti while make-up .
5.
Never exceeds the recommended torque as per API in order to avoid coupling or pin thread failure ( recommended using power tong ) .
6. 7.
Keep rods straight and centered while make-up also start every connection by hand to avoid cross threading. Inspect rods for damage , wear before re re-running running .
8.
Never exceed 90 % of the allowable rod tension in case of stuck pump .
Correct
wrong
Correct
wrong
wrong
Excessive tension
Correct
Incorrect
Wind
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