ALRDC Technical Library

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Gas Chamber Pump: “Perfection of High Volume Intermittent Chamber Technology”
by: Gossell, Steve — Added 3/2/2009 12:00:00 AMGeneral - Intermittent Gas Lift

Intermittent gas lift is utilized when reservoir pressure depletes below that of efficient continuous gas lift. Chamber lift is a common practice to enhance the starting slug size and increase the produced liquid rate by 2-5 times over conventional intermittent lift methods. A disadvantage of chamber lift is the large volume of gas required to lift the slug to the surface which causes system upsets on both lift gas system pressure and separation facilities; thus chamber lift historically is not applicable to offshore platforms.

Recently a refinement and simplification of a proven technology has made high volume chamber lift applicable to both onshore and offshore environments. Continuous gas lift is applied above the chamber to lift the produced fluids to the surface, so the gas required to purge the chamber is minimal. Rapid cycling of the chamber permits much higher volumes than historically associated with intermittent gas lift chambers.

Intermittent Gas-Lift Applications
by: Martinez, John — Added 6/1/2008 12:00:00 AMGeneral - Intermittent Gas Lift

Intermittent gas lift is a good application in low reservoir pressure wells that benefit from batch or slug production. The reservoir pressure or productivity has declined and the attainable flowing bottom hole pressure cannot effectively lift the continuous flow column of fluid.

The batch production technique allows the gas slug to lift a liquid slug, yet the column is mostly gas after the slug surfaces, which causes bottom hole pressure to be low and permits the reservoir to feed another small slug into the wellbore.

Data from testing will give the characteristics of the intermittent gas lift batch process. Application guidelines will be given for appropriate usage of intermittent lift.

Self-Tuning Algorithm for Intermittent Gas Lift
by: Gustavo Vinicius Lourenço Moisés; Jaildo de Jesús; Joseil Rodrigues da Silva; Nadilson Santos Muniz — Added 3/2/2009 12:00:00 AMGeneral - Intermittent Gas Lift

This work describes a self-tuning algorithm that was developed to identify equipment failures and behavior changes of Intermittent Gas Lift wells, improving the asset production cycle efficiency.

The shape of tubing and casing pressures cycle curves are the key elements of the algorithm that identify the most common failures related to Intermittent Lift Gas and infer well change behaviors such as water cut variations and production losses due to valves leakages or blockages, tubing leakage to the annular and short gas injection period. Without further system adjustments, this algorithm adapts automatically to the well’s parameters and informs its status by sending error messages to the SCADA system.

In addition, production indicators based on well status are used to measure the efficiency of maintenance and operator staff in order to maximize production and improve the asset work flow.

Shell Experience with Plunger Assisted Intermittent Gas-Lift (PAIL)
by: Moncur, Charlie — Added 6/1/2008 12:00:00 AMGeneral - Intermittent Gas Lift

Intermittent gaslift has not found much favour as an artificial lift technique in Shell Operating Companies. Shell has trialed and tested intermittent gaslift installations since 1962 in a number of its operating units. Success with intermittent lift has been limited due to the poor capabilities of the surface control units, hardware and the additional operational workload, which these systems generated. Intermittent gaslift was seen as an art rather than a science and placed in the “too difficult box”.

A specific intermittent lift technique PAIL (Plunger Assist Intermittent Lift) was developed and used in a Shell operating company over the last 2 decades. A total of 10 wells have been produced on PAIL with varying degrees of success. Despite the poor performance a number of wells have remained in production, for some 14 years, with PAIL systems. These wells have produced significant cumulative volumes of oil.