GAS LIFT VALVE MECHANICS © CAMCO 1998 GAS LIFT VALVE MECHANICS 3 basic types of gas lift valve, each available in 1” & 1-1/2” sizes: Dummy valves Orifice valves • Square edged • Venturi (nova) Unloading valves • Injection pressure (casing) operated valves • production pressure (fluid) operated valves • Throttling/proportional response valves © CAMCO 1998 UNLOADING VALVES © CAMCO 1998 Diaphragm/ Atmospheric Bellows Spring Stem Upstream/ Casing Stem Tip Upstream Downstream Port Downstream/Tubing Pressure Regulator Spring Operated Gas Lift Valve © CAMCO 1998 VALVE OPENING & CLOSING PRESSURES F=PXA Pd WHEN THE VALVE IS CLOSED TO OPEN IT….. 1 Pd x Ab= Pc (Ab - Ap) + Pt Ap Pd Pc 2 1 Pc WHEN THE VALVE IS OPEN TO CLOSE IT….. 2 Pd = Pc (Ab) Pt UN BALANCED VALVE © CAMCO 1998 VALVE OPENING & CLOSING PRESSURES CLOSING FORCE (IPO VALVE) Fc = PbAb OPENING FORCES (IPO VALVE) Fo1 = Pc (Ab- Ap) Fo2 = Pt Ap TOTAL OPENING FORCE Fo = Pc (Ab - Ap) + Pt Ap JUST BEFORE THE VALVE OPENS THE FORCES ARE EQUAL Pc (Ab - Ap) + Pt Ap = Pb Ab SOLVING FOR Pc WHERE: Pb - Pt (Ap/Ab) Pc = -------------------------1 - (Ap/Ab) Pb = Pressure in bellows Pt = Tubing pressure Pc = Casing pressure Ab = Area of bellows Ap = Area of port © CAMCO 1998 VALVE OPENING & CLOSING PRESSURES Pc = Pb - Pt (Ap/Ab) ---------------------1 - (Ap/Ab) Pc = Pb - Pt (R) ---------------------1-R Pb = Pc (1 - R) + Pt (R) Where R = Ratio Ap/Ab © CAMCO 1998 PRODUCED FLUID 0 500 1000 1500 2000 2500 3000 3500 INJECTION GAS 2000 DEPTH FTTVD 4000 6000 8000 10000 12000 14000 DRAWDOWN TUBING PRESSURE CASING PRESSURE FBHP SIBHP © CAMCO 1998 GAS LIFT VALVES CLOSE IN SEQUENCE 0 500 1000 1500 2000 2500 3000 3500 2000 DEPTH FTTVD 4000 6000 8000 10000 12000 14000 DRAWDOWN TUBING PRESSURE CASING PRESSURE FBHP SIBHP © CAMCO 1998 CASING P. TO OPEN PRODUCED FLUID INJECTION GAS CASING P TO CLOSE DOME P. AT SURFACE 1200 PSI ? PSI TUBING P. @ DEPTH VALVE # 1 1260 PSI ? PSI VALVE # 2 1300 PSI ? PSI VALVE # 3 1340 PSI ? PSI 560 PSI 740 PSI 890 PSI Pd = Pc (1-R) + Pt (R) NOTE : ALL VALVES 3/16” R-20 R = 0.038 1-R = 0.962 © CAMCO 1998 Dome Pb Dome Chevron Packing Stack Chevron Packing Stack Bellows Bellows Pb Stem Tip (Ball) Pc Square Edged Seat Pc Stem Tip (Ball) Square Edged Seat Pt Chevron Packing Stack Pt Check Valve Nitrogen Charged Bellows Type Injection Pressure (Casing) Operated Gas Lift Valve Chevron Packing Stack Check Valve Nitrogen Charged Bellows Type Production Pressure (Fluid) Operated Gas Lift Valve © CAMCO 1998 Dome Pb Atmospheric Bellows Spring Chevron Packing Stack Bellows Chevron Packing Stack Pc Spring Adjustment Nut & Lock Nuts Large T.C. Ball Tapered T.C. Seat Chevron Packing Stack Pc Pt Check Valve Nitrogen Charged Bellows Type Proportional Response Gas Lift Valve Stem Tip (Ball) Square Edged Seat Chevron Packing Stack Pt Check Valve Spring Operated Injection Pressure (Casing) Operated Gas Lift Valve © CAMCO 1998 © CAMCO 1998 © CAMCO 1998 GAS LIFT VALVE FEATURES • • • • • • • Bellows protection Max dome charge Check valve Stem travel Metallurgy Elastomers Max fluid rate © CAMCO 1998 UNLOADING GAS LIFT VALVE • Normally required during unloading phase only • Open only when annulus and tubing pressures are high enough to overcome valve set pressure • Valve closes after transfer to next station • May be spring or nitrogen charged © CAMCO 1998 ORIFICE VALVES THERE ARE 2 TYPES OF ORIFICE VALVE: • SQUARED EDGED ORIFICE • VENTURI (NOVA) • Valve designed for accurate gas passage prediction. • One-way check valve for tubing integrity. © CAMCO 1998 NOVA VALVE © CAMCO 1998 OPERATING GAS LIFT VALVE • Typically an ‘orifice’ type Gas lift valve • always open - allows gas across Passage whenever correct differential exists • Gas injection controlled by size and differential across replaceable choke • Back-check prevents reverse flow of well fluids from the production conduit © CAMCO 1998 GAS LIFT MANDRELS, LATCHES & KICKOVER TOOLS © CAMCO 1998 GAS LIFT MANDRELS SIDE POCKET MANDRELS CONVENTIONAL MANDREL © CAMCO 1998 5 1/2” MMRG-4, 1 1/2” POCKET ROUND MANDREL DESIGN Orienting Sleeve CAMCO Tool Discriminator ‘G’ Latch Lug Polished Seal Bore ENGINEERING DATA PART NUMBER SIZE MAX O.D. MIN I.D. DRIFT I.D. THREAD TEST PRESSURE INTERNAL TEST PRESSURE EXTERNAL LATCH TYPE KICKOVER TOOL RUNNING TOOL PULLING TOOL MATERIAL TENSILE STRENGTH (EOEC) 05712-000-00001 5 1/2” 7.982” 4.756” 4.653” 17 LB/FT MANN BDS B x P 7740 PSI 6280 PSI RK, RK-1, RKP, RK-SP OM-1, OM-1M, OM-1S RK-1 15079 1 5/8” JDS 15155 410 S.S., 13 CR 22 HRC MAX 490,000 LBS ï›™CAMCO 1996 © CAMCO 1998 © CAMCO 1998 © CAMCO 1998 © CAMCO 1998 © CAMCO 1998 RK / BK LATCH THERE ARE OTHER LATCHES • 1-1/2” RK • 1-1/2” RA • 1-1/2” RM • T2 LATCHES • 1” BK © CAMCO 1998 KICKOVER TOOL THE KICKOVER TOOL IS RUN ON WIRELINE AND USED TO PULL AND SET GAS LIFT VALVES. THE ABILITY TO WIRELINE CHANGE-OUT GAS LIFT VALVES GIVES GREAT FLEXIBILITY IN THE GAS LIFT DESIGN © CAMCO 1998 DAY 2 “LET’S DO GAS DESIGN” FLOW GAS LIFT WELL PRODUCED FLUID LIFT CONSTANT • Recap PRESSURE (PSI) 1000 2000 NG WI 0 0 O FL INJECTION GAS G BIN TU • Finish off outstanding work 1000 SU ES PR 2000 • Gas Lift Well Kick-off CASING PRESSURE WHEN WELL IS BEING GAS LIFTED T IEN AD GR RE • Gas Passage DEPTH (FT TVD) • Gas laws applied to 3000 gas lift design 4000 OPERATING GAS LIFT VALVE • Flowing gradient exercises 5000 • Gas lift design methods 6000 •Mandrel spacing SIBHP • Gas lift design - examples 7000 •Gas requirements FBHP •Port size selection •Pressure valve calculations © CAMCO 1998 RECAP - DAY 1 CONSTANT FLOW GAS LIFT WELL FLUID “ARM OURSELVES WITHPRODUCED THE KNOWLEDGE TO DO GAS LIFT DESIGN” PRESSURE (PSI) 1000 2000 NG WI 0 0 O FL INJECTION GAS G BIN TU • Course introduction 1000 CASING PRESSURE WHEN • Introduction to artificial lift WELL IS BEING GAS LIFTED 2000 • Types of gas lift 3000 • Applications of continuous flow gas lift OPERATING GAS LIFT VALVE • Advantages & disadvantages of gas lift 4000 • Basic introduction to gas lift principles 5000 • Continuous flow unloading sequence 6000 • Inflow and outflow performance 7000 • Gas lift valve mechanics • Gas lift mandrels, latches, kickover tools FBHP • Unloading sequence - computer model SIBHP T IEN AD GR RE DEPTH (FT TVD) SU ES PR © CAMCO 1998 © CAMCO 1998 © CAMCO 1998 GAS LIFT VALVE CHANGEOUTS! • • • • • • • • Methodical Equalise pressure Valve catcher Latches Running / pulling tools Pressure tests Experience Risk © CAMCO 1998 EQUIPMENT SUMMARY • Side pocket mandrels • IPO unloading valves • Fluid pressure operated valves • Proportional response valves • Orifice valves • Shear open valves • Latch system • Dump kill valves • Circulating valves • Pilot valves • Check systems • Waterflood regulators • Chemical injection systems • Time cycle controllers © CAMCO 1998 SURFACE ACTUATED/CONTROLLED GAS LIFT VALVE • Hydraulic controlled valve • Electric controlled valve © CAMCO 1998