INTRODUCTION TO OIL AND GAS PRODUCTION ENGINEERING

Artificial Lift Methods

ARTIFICIAL LIFT

• In the beginning of the oil industry it was recognized that the pressure of fluids inside the porous media provided the necessary energy to “lift” the fluids to the surface
• Techniques that use an external source of horsepower to help the reservoir in overcoming the pressures losses in the production system after the perforations receive the generic name of Artificial Lift

Artificial lift is the area of petroleum engineering that studies methods used to promote an increase in the production rate of flowing wells or to put wells back into production by using an external horsepower source to help the reservoir pressure to overcome the pressure drops in the system downstream of the perforations

ARTIFICIAL LIFT METHODS

There are several artificial lift methods

• Beam Pumping
• Continuous Gas Lift
• Electrical Submersible Pump
• Progressive Cavity Pump
• Hydraulic Jet Pump
• Intermittent Gas Lift
• Hydraulic Pump
• Plunger Lift
• Auto Gas Lift
• Other Traditional Methods
• Boosting Methods

The definition of Artificial Lift Methods requires the existence of a “external horsepower source”. Two comments must be made regarding plunger lift and auto gas lift

Plunger Lift can be operated in 2 modes

• Injecting supplemental gas. In this case it fits exactly the definition of Artificial Lift Method
• Without gas injection. In this case, there is no “external horsepower source” and plunger lift is considered an enhanced natural flow

Auto Gas Lift

• In auto gas lift the injected lift gas comes from a different production zone. There is no surface horspeower source. The “external horsepower source” is the lift gas zone. This can be considered as a natural flow of two zones being produced simultaneously

ARTIFICIAL LIFT – USES

In Oil Wells

• Boost production
• Put wells back into production
• Stabilize production

In Gas Wells or CBM Wells

• To remove condensate or water from wells

BEAM PUMP

• Familiar to engineers and operators
• Simple design
• Low capital investment for low production at shallow to medium depths
• High investment for high flowrates in deep wells
• Allow very low fluid levels (low bottom hole flowing pressure)
• Adaptable to scale and corrosion problems
• Limitation with casing size
• Adaptable to automation
• Not suitable for crooked holes

CONTINUOUS GAS LIFT

• Low investment for deep wells
• Most efficient for high GLR
• Low operating costs for sand production
• Flexible
• Adaptable to crooked holes
• Capable of producing very high flowrates
• Requires a source of high pressure gas
• Can not achieve very low bottom-hole flowing pressures
• Casing and lines must withstand gas pressure

ELECTRIC SUBMERSIBLE PUMP (ESP)

• Can produce very high flowrates from shallow to medium depths
• Low investment costs for shallow depths
• Adaptable to automation
• Casing size is not critical for high flowrates
• Electrical cable design is the weakest link
• Needs a VSD to be flexible
• Requires a stable source of electricity
• Big problems with scale
• Requires workover to remove unit

PROGRESSING CAVITY PUMP

HYDRAULIC JET  PUMP

INTERMITTENT GAS LIFT