Artificial lift

Artificial Lift

Artificial Lift Overview
Introduction What is Artificial Lift? When is Artificial Lift required? How is Artificial lift Performed?

Introduction
Performance of a Well governed by: Capacity of a Reservoir to pass fluids to the wellbore against downhole conditions (Inflow Performance) The ability of the produced fluids to flow trough the well up the tubing to surface(Outflow performance)
“That a may be capable of flowing naturally does not mean that artificial lift should not be considered. Many wells are capable of producing more higher rates whe placed on AL”

What is Artificial Lift
A well will flow as long as the bottom flowing pressure remains greater than the sum of both the hydrostatic pressure of the fluid in the tubing and the required pressure in thesurface production facilities Alternative techniques can be used to help lifting fluids to surface. These techniques are termed Artificial Lift

When is Artificial Lift required?
Add energy to the effluent to accelerate or to enable production . May be required at different stages over the life of a well Required at the beginning of production when: The well may not flow at all on naturalflow The well may not flow efficiently enough on natural flow The well needs to mechanically get started before flowing on natural flow

When is Artificial Lift required?
AL most commonly required later in the life of a well as: Reserves deplete Reservoir pressure decreases Well productivity drops

How is Artificial lift Performed
To add energy to the produced fluids in the well whiledecreasing the downhole backpressure against the the reservoir Two main processes to achieve this: Mechanically lifting by pumping Lightening the column of fluid by injecting gas into it, or gas lift

How is Artificial lift Performed? Pumping techniques
The objective is to transfer mechanical to the fluid in the production string by squeezing, pushing or pulling it to surface Pumping technologiesavailable today include: Sucker Rod Pump or Bean Pump Progressive Cavity Pump Electric Submersible Pump Hydraulic Reciprocating Pump Hydraulic Jet Pump

How is Artificial lift Performed? - Pumping techniques
Beam Pump Electric Submersible Pump (ESP)

How is Artificial lift Performed? - Pumping techniques
Hydraulic pump Progressing Cavity Pump (PCP)

How is Artificial lift Performed? GasLift Methods
Gas lift methods aims at lessening the fluid density in the lower part of the production string to provide the fluid with higher potential energy. Continuous Gas lift Intermittent Gas Lift

How is Artificial lift Performed? –Gas Lift Methods

Naturally Flowing

Gas Lift

Beam Pump
Principle of Operation Components Pump Selection Advantages & Drawbacks

Beam Pump -Principle of Operation
Sucker Rod pump Oldest and most common artificial lift method Simple in design and widely used over the world Very economical in low production wells in shallow to middle depth oil fields Uses a vertical positive displacement pump consisting of a barrel with a check valve at its bottom (standing valve) and a plunger fitted with another check valve (traveling valve). The downholeplunger is mechanically connected to a surface walking bean by sucker rods. The pump is rocked up and down by the movement of the walking bean driven by an electric or reciprocating motor.

Beam Pump - Components
Downhole pump: Two categories Insert Pump Tubing Pumps Sucker rods Tubing Anchor Gas Separator Pumping Unit

Beam Pump – Pump Selection
Pump performance evaluated based on thevolume of fluid displaced instead of the pressure increase generated by the pump. Downhole volumetric flowrate generated by a bean pump is given by:

Q = S*N *A

Where S is the stroke length (in) N is the number of strokes / minute A is the plunger cross sectional area (in2)

Beam Pump - Advantages & Drawbacks
Advantages Most wide spread AL system, relatively simple and cheap, best known by...