ARTIFICIAL LIFT IN DEPLETED RESERVOIRS

Transcription

1 ARTIFICIAL LIFT IN DEPLETED RESERVOIRS Why Ar'ficial Li. Comparison of Ar'ficial Li. Methods - Typical Ranges Ar'ficial Li.ing the Mississippian Wells Ar'ficial Li.ing Horizontal Wells Plunger Li. vs Rod Pumping The Rod Pumping Method Advantages The Rod Pumping Efficiency Rod Pumping Horizontal Wells The Plunger Li. Method Advantages Methods Plunger Li. in Horizontal Wells

2 Why Ar4ficial Li: 2. When the pressure of the reservoir fluids within the pore spaces is less than or change with 'me to the hydrosta'c head of the total produced fluids to the surface.

3 ROD PUMP AS A SUSTAINABLE ARTIFICIAL LIFT METHOD IN DEPLETED RESERVOIRS Analyzing beam pump performance data to determine viability of rod pump u4liza4on Determining op4mum rod pump design to maximize oil recovery Comparing plunger li: vs. rod pump performance to iden4fy the most effec4ve op4on U4lizing rod pumps for depleted wells to recover previously unaqainable hydrocarbons.

4 The profitability of ar'ficial li. opera'ons is a direct func'on of the energy requirements of the system. For maximum profits, the efficiency of the system must be maximized, this can only be achieved by finding the maximum mode for the required liquid produc'on rate. With the aim of improving the field- wide profitability of the opera'ons, an op'miza'on of each well s parameters should be made

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6 Plunger li: Rod Pump Capillary String ESP PCP Hydr Recipr Hydr Jet Gas Li: Opera4ng Depth, : TVD 8, ,000 8,000-12,000 1,000-10,000 1,000-5,000 7,500-10,000 5,000-10,000 5,000-10,000 Opera4ng Volume BFPD Opera4ng Temp, F , , , , , Corrosion Handling Excellent Good- Excellent Gas handling Excellent Fair- Good Excellent Poor- Fair Excellent Good Excellent GOOD Excellent Good- Excellent Moderate- Good Fair Good Excellent Solids handling Poor- Fair Fair- Good Fair- Moderate Poor- Fair Excellent Foor Godd Excellent Crude API >8 >8 >8 >10 <30 heavy oil >8 >8 >15 Well Servicing Catcher- Wireline Pulling rig Capillary Unit Pulling Rig Pulling rig Hydraulic- Wireline Hydraulic- Wireline Wireline- Pulling Rig Hole Devia4on Good in 0-20 deg deviated wells landed pump Good in 10 deg - deep deviated wells and dev wells Dogleg >15 deg/1000' Prime Mover Well s Energy Gas - Electric Well s Energy Electric Gas- Electric 0-20 deg landed pump Mul4cylinder- Electric 0-20 hole angle 0-50 deg Multucylinder- Electric Compressor Capital & power Low Medium Low High Low High High HIgh Offshore N/A Limited Good Excellent Good GOOD Excellent Excellent Efficiency N/A 45% - 60% N/A 35%- 60% 50%- 75% 45% - 55% 10%- 30% 10%- 30%

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8 ARTIFICIAL LIFTING HORIZONTAL WELLS Plunger lift Rod Pump Capillary String ESP PCP Chamber Lift Hydr Jet Gas Lift Operating Volume BFPD 5 to 50 bfpd Limit around 1,000 bfpd Large volumes Varies, of fluids usually low >20,000 bfpd Low Tubular and depth limited Varies with gas used Deviation Applicability To about 20 deg Vertical Section with tbg anchor Requires straight section Can work fully horizontal Can work fully horizontal Best in vertical Can work fully horizontal zontal Can be operated at any deviation Efficiency limited to 70 deg Gas Tolerance Good Requires separation Susceptible to Excellent gas locking Requires separation Excellent GOOD Limited Good Lift Efficiency N/A Not usually deviated Excellent (if gas shielded) Good but rate limited Unknown Moderate Poor in horizontal Solids handling Poor Poor Poor Excellent Good Moderate to Poor Excellent Comments Low rate liquid removal Deviation limited by rod wear. Required constant flow & straight landing point Requires straight landing point & protected bearings Slugging flow Requires flow path for power fluids High gas rates required to lift

9 Typical Ar'ficial Li.ing of Marginal Mississippian Wells TYPICAL PRODUCTION Oil: 2-15 BOPD Water: BWPD Gas: 5 30 MCFD ARTIFICIAL LIFT METHOD Beam Pumping The most widely used Plunger Li. In less than 1% of wells

10 ROD PUMPING Highly efficient. Posi've displacement and strong drawdown produce the well to deple'on. Flexible. Adjust produc'on thru stroke length and speed. Op4miza4on. Controls available. Upgraded materials. Reduce corrosion. High Salvage Value. Surface and downhole materials. Limita4ons. Poten'al tubing and rod wear High GOR Volume decreases as depth increases Environmental and aesthe'c concerns Poten'al for high failure rates

11 PLUNGER LIFT Flexibility. Tubing or casing designs. Outside Energy. Not required. Low Cost. Capital, power and maintenance. Maintenance. Not requiring a pulling rig. Paraffin deposi4on. Keep tubing cleaned. Increase produc'on in wells with paraffin problems. Deviated wells. Good. Efficiency. Can produce wells nearly to deple'on. High GLR wells ,000 SCF/BL/ Dewatering gas wells enhances produc'on. Limita4ons: Low volume poten'al.

12 PLUNGER LIFT- ADVANTAGES Requires no outside energy. Low cost ar'ficial li. method. Dewatering gas wells, and enhance produc'on in high GLR wells. Easy maintenance, not requiring a pulling rig. Keep wells cleaned of paraffin. Good in deviated wells. Can produce wells nearly to deple'on. Unload wells that con'nue to load up. Increase produc'on in wells with paraffin problems. Enhances produc'on in high GLR wells. In 500 1,000 SCF/BL/ Low volume poten'al.

13 BEAM PUMPING Downhole pumps. Double standing valves and double traveling valves. U'lized to extend the life of the pump in the presence of solids. Back up valve when top valve fails Great chance of gas locking. In new horizontal wells 30% u'liza'on Double standing valve and single traveling valves. U'lized in mild solids and gas produc'on. More secure. 30% u'liza'on Single standing valve and single traveling valve. U'lized for severe gas situa'ons Prevent gas locking. U'lized in new or recompleted wells. 40% u'liza'on

14 ROD PUMPING DOWNHOLE PUMPS USED The life of the pump depends on the the grade of the material, stroke length, and SPM to pump the well down. Most common type of downhole pumps in the Mississippi Lime is the RWBC and RHBC. Bore size is typically from 1 ¼ to 1 ½" in most ver'cal wells. Most wells produce less than 100 BPFD. Sea'ng nipple is set usually below the bojom perfora'on depending on the rate. In frac wells with sand the SN is set 100. on top of perfs to give sand 'me to sejle in the rat hole. Most Mississippi Lime waters are corrosive. Selec'ng the right grade of materials to build the pump is the outmost importance. Pumps built with bronze chrome or bronze nicarb barrels and SS parts last way longer. Common prac'ce to run a mud anchor below the SN and gas anchor on pump to act as gas separator. In horizontal wells with insert pump, it is best to run an Odessa and sand shield separator that acts as gas separator. A top sliding sleeve will help the efficiency of the pump.

15 ROD PUMPING EFFICIENCY Total efficiency of the system in terms of energy losses (horse power u'liza'on). E = Eli..Esurf Esurf = Energy u'liza'on and energy losses in the pumping unit, the gearbox, the V- belt valve, and electric motor. Eli. = Energy u'liza'on and energy losses in the downhole system: the pump and rods. Pump displacement efficiency: capacity of the dowhole pump to displace the required fluid to surface. Eƞ = Qr/Qi where, Qr = Produc'on at surface. Qi = Induced or designed li.ing volume = Stroke per Minute x Stroke Length x Pump Factor PF = Func'on on pump size. Pump displacement efficiency Eƞ = Qr/Qi = Qr/(SPM. SL.PF)

16 THE ROD PUMPING DISPLACEMENT EFFICIENCY Qr = Qi x Ev = Ev (SLxSPMxPF) Eƞ = Qr/Qi = Qr/(SLxSPMxPF) Eƞ > 100% Eƞ = 100% Qr Eƞ <100% Qi = li.ing design = SLxSPMxPF

17 THE ROD PUMPING DISPLACEMENT EFFICIENCY Qr = Qi x Eƞ = Eƞ (SLxSPMxPF) Eƞ = Qr/Qi = Qr/(SLxSPMxPF) Eƞ = 100% Qr Qi = li.ing design = SLxSPMxPF

18 THE ROD PUMPING DISPLACEMENT EFFICIENCY Qr = Qi x Ev = Ev (SLxSPMxPF) Ev = Qr/Qi = Qr/(SLxSPMxPF) Ev = 100% Qr Qi = li.ing design = SLxSPMxPF

19 Beam Pumping Horizontal Wells Beam pumping is suscep'ble to gas locking, dragging and erosion. In the deviated sec'on the rods slide against the tubing and may erode it unless rod guides are used. In addi'on, the system faces the effect of back pressure. About 1,000. to 1,500. of liquid le. in the hole may hold as much as 450 psi to 500 psi back pressure.

20 Gas Li.ing Horizontal Wells Ø Gas li. faces challenges of in horizontal wells. Ø The biggest challenge is gesng the gas li. equipment in place. Ø Wireline tools work to a devia'on between 65 and 75 deg inclina'on. Ø Pusng gas li. equipment in the horizontal part or highly deviated sec'on requires coiled tubing or special tools.

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