Gas lift 

AHMAD HAFIZAN B MUHD MUHAYYIDIN GHAZI BIN MOHD ALIF

MOHD SHAHRUL NIZAM BIN IBRAHIM

AFENDI BIN ABU TALIB

MUHAMMAD FADZIL B. ABD. RANI

Intro Component Operational principles Optimization Advantages and disadvantages conclusion

overview

Introduction

Gas Lift Valves

Component

Operational principles

Continuous•Continuously injecting gas into the tubing or casing at a predetermined depth to decrease the pressure opposite the producing formation.

Intermittent Flow

•Injection of high pressure gas into the tubing at adequate volume and pressure to lift the fluid head accumulated above the valve with maximum velocity.

How does gas lift work?

Gas is injected into the casing.

Fluid is u-tubed through all open valves.

No formation fluids being retrieved because all fluids are from the tubing and casing

The fluid has been unloaded to top valve #5 .

The fluid is bubbling above this point in the tubing and fluid density decreases.

Pressure is decreased at top valve, as well as all lower valves.

Unloading carry on through lower valves.

Fluid level is now below valve #4.

Injection transfers to valve #4 and pressure is lowered.

Casing pressure declines and valve #5 closes.

Unloading continues through lower valves.

All gas is being injected through valve #4 .

Lower valves remain open.

A decline in casing pressure causes upper valves to close in series.

All gas is being injected through valve #3 .

Lower valves remain open.

A decline in casing pressure causes upper valves to close in series.

Valve #2 open; this is the Point of Injection

Casing pressure is affected by operating valve set pressure

Upper valves are closed

Valve #1 remains submerged unless operating situations change in the reservoir

Main objective to identify optimal gas injection allocation

such that maximizing oil production

Optimization

High degree of flexibility and design rates

Wireline retrievable

Excellent handling of sandy conditions

Allows for full bore tubing drift

Minimal surface wellhead requirements

Advantages

Surface control of production rates

Multi-well production from single compressor

Multiple or slimhole completion applications

Minimal moving parts

Advantages

Source of gas must be available to ensure continuous process of gas lift.

The gas needed to be treated first because some of it are corrosive. This increases the cost of gas lift.

The initial gas lift system installation usually comes with expensive cost compared to other single well pumping system and also requires longer lead time and greater preparation..

Disadvantages

This lift system is not suitable for very low pressured reservoirs because it cannot achieve as great a pressure drawdown as some conventional pumping system.

The conversion process of original old well to gas lift system’s well needed high level of casing integrity compared to normal pumping system.

Disadvantages

Sour gas

Wet gas subject to freezing

Paraffin

Low viscosity crudes

Limitation factor

Gas lift made the production of oil more efficient and economic.

The gas lift BEST for producing when producing wells can’t flow on their own, increasing the production of a flowing well, producing deviated and horizontal wells, and overcoming sand and scale problems

To make the gas lift more economical and more efficient, the optimization of the gas lift needed to be done

Conclusion