cge 654_lect 4_artificial lift.pdf

Artificial Lift

Faculty of Chemical Engineering

CGE 654

Well

Completion


Lesson Outcomes:At the end of this chapter, students should be able to:

Understand artificial lift requirements Artificial lift techniques Describe the operational principle, components, advantages and disadvantages of the main artificial lift methods/techniques Selection of artificial lift


Artificial Lift

• Overview of producing oil from well

Oil or gas reservoir is discovered and assessed, production engineers begin the task of maximizing the amount of oil or gas.

Early in its production life, the reservoir pressure maybe sufficient to sustain natural flow.

The reservoir pressure will gradually declines as it gets older - insufficient for the oil to flow naturally

Some method of lifting the liquids, such as mechanical pumps, must be used to bring the oil to the surface.


Artificial Lift

• Introduction

Artificial lift is a process used on oil wells to increase pressure within the

reservoir and encourage oil to the surface.

Mean to increase the flow of liquids, such as crude oil or water, from a

production well.

When there is insufficient pressure in the reservoir to lift the produced

fluids to the surface, artificial lift is employed to recover more production.

But, often used in naturally flowing wells to increase the flow rate above

what would flow naturally.


Artificial Lift

Relative frequency of different types of artificial-lift methods installed in the USA in 1992 (data from J.Clegg, S.Buchan and N.Heln, JPT, December 1993, p1128)

Production from artificial lift wells for a major international oil company


So…Artificial Lift…

Any system that adds energy to the fluid column in a wellbore with the objective of initiating and

improving production from the well.(http://www.coscoesp.com)


Artificial Lift

• Purposes:

To maintain a reduced bottom hole pressure (Pwf) to enable the

desired reservoir fluids to be produced at an acceptable rate

To provide the fluid with the necessary energy to reach the surface

and continue flowing to the surface.

If the appropriate drawdown can be maintained the future

management of the reservoir and completion can be conducted

efficiently.


Artificial Lift

• Methods of artificial lift:

Pumping systems Beam Pumping / Sucker Rod Pumps (Rod Lift)

Progressive Cavity Pumps

Subsurface Hydraulic Pumps

Electric Submersible Pumps

Gas lifts - The technique of increasing the flowing life of a well by the

injection of gas into the tubing.

Continuous gas lift

Intermittent gas lift


Artificial Lift


Artificial Lift

• Artificial lift selection criteriaWell and reservoir characteristic

Field location

Operational problem

Economics

Implementation of artificial lift selection techniques


Artificial Lift

Artificial lift selection criteria1. Well and reservoir characteristicProduction casing sizeMaximize size of production tubing and required (gross) production ratesAnnular and tubing safety systemsProducing formation depth and deviationNature of the produced fluids


Artificial Lift

Artificial lift selection criteria2. Field locationOffshore platform design determines the maximum physical size(limitation) and weight of artificial lift equipment that can be installedClimate extremeOn-shore environment

Urban location – require minimum of visual and acoustic impactRemote location – min availability of support infrastructure

Distance from the wellhead to the processing facilities Power source – natural gas, mains electricity, diesel generator


Artificial Lift

Artificial lift selection criteria3. Operational problemSome form of artificial lift (e.g. gas lift ) more tolerance to solids production (sand) than the other (e.g. centrifugal pump)Formation of massive organic and inorganic deposit (e.g. paraffins, asphalthenes, inorganic scales and hydrates) – prevent by treatment with suitable inhibitors & require additional equipment @ complicated downhole completion required


Artificial Lift

Artificial lift selection criteria4. EconomicsMaintenance costs will vary between operating location depending on the state of the local, service company infrastructureThe number of wells in the field with that particular form of artificial lift will influence the operating cost.


Artificial Lift

Artificial lift selection criteria5. Implementation of artificial lift selection techniquesConcern due matching facility constraints, artificial lift capabilities and the well productivityCertain environmental and geographical considerations that may be overridingSome artificial lift are able to reduce the sand face producing pressure to a very low valueWax and formation solid present greater difficulties to some forms of artificial lift designer


Artificial Lift


Presentation:

• Monday (22 May 2013)• 10-15 minutes • Contents:- Principle of operation- Components- Diagrams- Applications- Advantages & disadvantages- Video- Etc