Introduction
Basic Principles of Oil Production
Reservoir Pressure and Flowing Pressure
Reservoir Energy (Source of Energy)
Reservoir Drive Mechanism
Strong Waterdrive
Partial Waterdrive
Depletion
Factors That Affect Oil Production
Amount Of Gas
Water Associated With Oil
Reservoir Properties
Producing Pipe Size
Size and Length of Flowline
Natural Flow and Artificial Lift
Artificial Lift
Types of Artificial Lift Systems
Pumping
Gas Lift
Choosing Artificial Lift system
Gas Lift System
Types of Gas Lift
Continuous Flow
Intermittent Flow
Low Reservoir Pressure
Low Producing Rate
Advantages of Gas Lift System
Low Cost
Design to Lift Different Rate
Injection and Producing Rate Controlled at Surface
Sand Production Doesn’t Affect G.L. Equipment
Not Affected by Wellbore Deviation
Operating Costs are Relatively Low
Gas Compressor Easily Inspected and Maintained
Limitation Of Gas Lift System
Gas Availability
Source of High Pressure Gas
Treat or Dry the Gas Before use
Gas Lift Concept
Density Reduction
Reducing Flowing Bottom Hole Pressure
Improving The Gas To Liquid Ratio
Increasing The Mixture Velocity
Changing Flow Regime
(Vapor-Liquid Distribution)
Reducing Liquid Holdup
Reducing Wellhead Pressure
Reservoir Draw Down
Liquid Production Rate
Reservoir Pressure
Flowing Bottom Hole Pressure
Productivity Index
Inflow Performance Relation Ship
Optimization
Unloading
Unloading Procedure
Valves in Opening Condition
Valves in Closing Condition
Factors Can Prevent Deep Injection
Steady State Production
Steady State Pressure Gradient
Gas Lift Fluid Pressure Gradient
Formation Fluid Pressure Gradient
Injection Gas Pressure Gradient
Inflow Performance
Reservoir Deliverability
Saturated and Under saturated
Reservoir
Bubble Point Pressure
Darcy IPR Curve
Applied when the well is flowing above Bubble Point Pressure
Equation for Productivity Index
Factors That Affect Productivity
Permeability
Viscosity
Oil Volume Factor
Net Height
Skin
Vogel IPR Curve
Applied when the well is flowing at pressure below B. Pt
Equation for Productivity Index
Maximum Rate Qm (Absolute)
Pr = Pb
Fitkovitch IPR Curve
Applies for:
Gravel Packed Well
Partial Perforation of a High KH Reservoir
Excessive Formation Damage
Fitkovitch IPR Curve, Continue
Equation
Multiple Rate Well Tests
Use Log-Log Plot
Obtain n (1/slope)
Inflow Performance Prediction
Effect of Reservoir Drive
Mechanism
Above Bubble Point
Below Bubble Point
Outflow Performance
Flow Line plus Vertical Pressure Loss
Losses in Flow Line
Losses in Vertical (Deviated) String
Obtain Measured Flowing Pressure
Factors That Affect Outflow
Performance
Fluid Characteristics
Well Configuration
Wellhead Back Pressure
Pipe Roughness
Fluid Velocity
Outflow Correlation
Duns and Ros
(Large diameter tubing, high GLR, low & mist flow
rates)
Orkiszewski
(Slug flow, moderate liquid volume fractions)
Griffith and Wallis
(High liquid volume , low GLR)
Outflow Correlation, Continue
Beggs and Brill
(Small diameter from 1 to 1.5 in)
Hagedorn and Brown
Provides the best prediction for wellbore
simulation
H&B, Duns and Ros best for offshore deviated wells
Reservoir Match
Obtain IPR (Inflow)
Obtain Outflow (Correlation)
Test Point
Match P.I.
Intersection Point
Outflow Performance
Gilbert’s Curves
Stability of Flow
Different Depth of Gas Injection
Pressure Gradient
Kick-off Pressure
Well Completion
Outflow Performance Prediction
Deliverability vs Injection-depth
Deliverability vs IGLR
Water Cut % effect
Well Completion
Well Head Pressure
Gas Lift Equipment
Gas Lift Valves
Bellows
Stem
Seat (Port)
Check Valve
V-Packing
Types of Gas Lift Valves
Tubing Flow
Annular Flow
Continuous Flow
Intermittent Lift
Checks, Latches & Mandrels
Checks (Check Valve)
To prevent back flow from tubing and fill-in the
casing annulus
Latches
Screw to the top of the valve provides the neck for
wireline tool engagement
Mandrels (Side Pocket)
Valves Mechanism
Closing Force
Opening Force
Test Rack Opening Pressure
Gas Passage
Installation and Removal
Wireline Procedure
Running and Pulling
Gas Lift Design
Continuous Flow Design
Pressure Gradient
Injection Gas Gradient
Water Gradient
Spacing
Temperature
Valve Selection (Type & Port Size)
Wiskey Valves
Gas Lift Design
Continuous Flow Design, Continue
High & Low Rate Wells
Injection Gas Requirement
Corrected Temperature Profile
Flowing Survey
Orifice & Dummy Valves
Continuous Flow G.L. Redesign
Gas Injection Pressure
Temperature Survey
Gas Volume
Production Decline
Design of Intermittent Lift Installation
Fallback Method
Spacing Factor Gradient (Unloading Gradient)
Function of Production Rate and Tubing Size
Gas Pressure Gradient
Valve Closing Pressure Gradient
Temperature Correction
Decrease Set Pressure of Bottom Valve 25-30 psi
(Flagging the bottom valve)
Design of Intermittent Lift Installation
Percent Load Method
Gas Pressure Gradient
Percent Load Line (60% of Gas Pressure)
Pbt (Nitrogen Charged Valve)
Psp (Spring Loaded Valve)
Pvo (Valve Opening Pressure in Tester)
Decrease Set Pressure of Bottom Valve 25-30 psi
(Flagging the bottom valve)
Design of Intermittent Lift Installation
Fluid Operating Valve
Actual Flowing Pressure Gradient
Use of Dummy Valves
Pressure and Production Decline
Dual Gas Lift Installation
Both tubing strings take gas from the same gas
source
System allow extra gas to go in one side than
other. Results in one or both zones producing at
less than optimum
Use injection pressure-operated in one side and
production pressure operated in the other
Two Pen Chart Pressure Recordings
Reflect Both Surface and Subsurface
Conditions
Record Valves Open, Gas Entry Stops
Unloading Procedure
Evaluate Intermittent System
Calculate Gas Volume
Gas Lift System Evaluation
Pressure & Temperature
Flowing Gradient
Procedure
Objective
Gas Lift Survey Procedure
Stop at Surface (Get WHP, WHT)
Get Gas Lift and Formation Gradient
Stop above and below Mandrels
Stop at Mid Point of Perforation
Gas Lift Survey Objective
Get Point of Gas Injection
Determine Possibility of Deeper POI
Get Valves Leak (Gas passes at more than one point)
Mandrels Plugging Condition
Gas Injection Optimization
Gas Lift Design Evaluation
Select the Type of G.L. System
Unloading The Well
Use Unloading Chart
Check and Adjust Chokes and Valves at Surface
Control Lift Gas into the Well
Increase Lift Gas Until gas Passes into the
Valves
Monitor (From Chart) Wellhead and Gas Pressure
Responce
Recommended Practices Prior To Unloading
Clean the well of mud prior to running G.L.
Valves to avoid damage
Reverse circulation should not be used (Injection
gas pressure operated valves)
Clean injection gas line before connected to the
well
Check separator capacity, stock tank liquid
valves and connections at wellhead
Tubing and Casing Pressure Records
Increased flowing production pressure indicates
increase in separator back pressure and volume
of injection gas
Decreased production pressure indicates drop in
supply gas pressure or volume
Detected the changing in operating valves
Indicated hole in tubing or bad G.L. Valves
Indicated excessive gas usage
Trouble Shooting
Basic Information should be obtained
Two Pen Chart
Production Rate (Water, Oil & Gas)
Injection Gas per Day, IGLR
Number of Cycles per Day
Injection Gas Pressure
Variations of Casing and Tubing Pressure
Point of Gas Injection
Static and Flowing B.H. Pressure
Pressure and Temperature Gradient
Trouble Shooting
Analysis of problems gas lift wells
New Wells
Old Wells
Trouble Shooting
Common Malfunctions of G.L. System
Malfunction
Cause
Cure
Gas Pressure Loss
Separator To Compressor
Gas Rate
Upstream & Down Stream Pressure
Pipe Length
Pipe Inside Diameter
Gas Pressure Loss
Compressor To Well
Operating at Higher Pressure
Gas Friction Loss is Low
Gas Pressure Loss
Wellbore Losses
Density of the Gas (Specific Gravity)
Obtain Gas Gradient
Surface Injection-Gas Pressure
Production Optimization
Optimum Injection Gas
Maximum Production Rate
Production Optimization, Continue
Using Surface Gas Choke
Subsurface Information (D.D. Calculation)
Inflow & Outflow Relation Ship
Optimization Curve
Injection Gas vs Oil Rate
Incremental IGOR vs Oil Rate
