GAPL & PAGL
About
Many people use these terms interchangeably to refer to combinations of gas-lift and plunger-lift. While we know of no formal SPE definition, we use GAPL to refer to gas-assisted plunger-lift, and PAGL to refer to plunger-assisted gas-lift. With this perspective, PAGL and GAPL can come at two distinctly different times in the life cycle of the well.
​
While the proper application of PAGL and GAPL can both bring improvements to production over one form of lift alone, they are also distinct forms of lift that can be planned for in the life-cycle of the well. By designing the well to anticipate the changes and minimize the workover costs, production and economic efficiency can be optimized.
GAPL
Plunger-lift assisted by continuous or intermittent gas injection:​
​
The gas injection assists and extends the economic life of the plunger-lift system by supplementing the reservoir drive. The amount of time that a plunger-lift system can operate towards the end of the life cycle, before switching to another form of lift, can be extended.
PAGL
Continuous gas-lift, assisted by a continuous-run plunger:​
​
The plunger assists and extends the economic life of the gas-lift system by improving the efficiency and economics at lower rates. The amount of time that a gas lift system can operate towards the end of the life cycle, before switching to another form of lift, can be extended.
As the economic efficiency of a gas lift system declines, often an investment is required to switch to an entirely different form of artificial lift. In many cases, combining a plunger with gas lift can boost production and extend the economic life span of a gas lift system.
What can GAPL do for you?
If you are looking to extend the production and life-cycle of your plunger-lift system, then Gas Assisted Plunger Lift may be a valuable option. At lower reservoir pressures and rates – GAPL is the application of intermittent gas lift to assist a plunger lift system. GAPL can be applied when the formation drive is below the requirement to operate a plunger system independently, or when improved plunger performance can be created by utilizing gas compression. Key points like when should a horizontal well be shut in after the plunger arrives is critical to the production results and overall success. Planning ahead and using a Life Cycle of the Well strategy can make significant savings and simple transitions between gas lift, PAGL, GAPL, and plunger lift successful throughout the life of the well.
What can PAGL do for you?
The plunger not only helps to sweep liquid fallback to the surface and reduce BHP, but it effectively improves the ability of the gas to move the liquid so that injection rates can be reduced, and the effect of slippage can be minimized. Even in a gas-lifted well that is fully optimized, the addition of a plunger can reduce injection rates by 25 to 40% and improve liquid rates by 10 to 30%. This changes the economic viability of a gas lift system at lower rates and can delay the capital expense of moving to another form of artificial lift. Plungers also bring the proven benefit of helping to clean up scale and paraffin issues. The plunger can be set as deep as 60° for optimum BHP management.
Injection Rates
& OPEX
Production
We use nodal analysis to predict when a plunger may improve well performance, but some of the key signs are:
​
-
Liquid rates below 450 BPD
-
Production is becoming unstable and starting to surge or head
-
On multi-well pad sites where injection rate capacity is needed by other wells
-
Scale or paraffin buildup is impacting production​
​
The increasing adoption of gas-lift has created many opportunities for PAGL where traditionally this form of lift has not been properly evaluated. Once a well is deemed a candidate for PAGL, proper design of the system is key, as is the placement of bottom-hole spring assembly, and selection of the proper plunger can make all the difference in meeting performance expectations. In too many fields, improper attention to these details has lead to a system where the plunger cannot effectively get off the bottom, leading to the PAGL approach being mistakenly abandoned.
For more information please contact us below or reach out to your Account Manager. To find your Account Manager, check out our Service Map.