Intermittent Gas Lift

Continuous Flow Gas Lift

Continuous Flow Gas Lift

Intermittent Gas Lift

If you’re looking for a method of artificial lift to optimize production all the way from kickoff to depletion of your well, then Flowco Gas Lift is the answer.

Types of Gas Lift

Continuous Flow Gas Lift

The majority of gas lift wells are continuous flow gas lift. This type of gas lift is the most common because it resembles the natural flow of a well. Using a continuous injection of compressed gas into the well reduces reservoir pressure and increases production.

Intermittent Gas Lift

When low reservoir pressure and low production rates are present in a wellbore, intermittent gas lift can be a better option. In this process, high-pressure gas is injected in intermittent cycles to displace liquid slugs to the surface. This type of gas lift is only used for tubing flow. Due to high injection rates from the compressor in intermittent gas lift, the energy in the formation gas does little to assist in lifting most wells.

Casing (Annular) Flow

Typically, this application is sought in highly productive wells, where tubing flow can limit maximum production rates. With casing (annular) flow, the gas is injected down the tubing string and fluids are produced out of the tubing/casing annulus. Higher gas lift injection rates must be available to prove efficient in this application and surface facilities must be set up to handle higher fluid volumes.

Four Hands on Deck

With casing (annular) flow, the gas is injected down the tubing string and fluids are produced out of the tubing/casing annuli. Higher gas lift injection rates must be available to prove efficient in this application and surface facilities must be set up to handle higher fluid volumes.

Gas Lift Mandrels

Gas Lift Mandrels
Left: Conventional Gas Lift Mandrel
Right: Wireline Retrievable Side Pocket Mandrel

 

Beyond conventional, continuous flow applications:

Packer Bypass System (PBS)

The Packer Bypass System (PBS) is a nice combination of the conventional gas lift system with a packer, and the open-ended, packerless system. With tubing and gas lift valves above the packer and a bypass assembly, injected gas can travel through the packer. This allows the gas lift system to reach the end of the tubing tail below the packer, in the curve of the wellbore. This is the ideal point of lift for the lowest flowing bottom-hole pressure and lowest flowing gradient. With injection gas above and below the packer through the unloading of the well, it is easy to treat the tubing and casing string with chemicals, if needed. When the well is shut-in, the packer prevents fluid from re-entering the annulus above the packer, and exposing the upper gas lift valves to fluid and wellbore “trash.” Upon resuming gas injection and unloading the well again, this prevents issues such as a hung open gas lift valve or erosion of gas lift equipment, when kicking the well back off.

IAV Bluein

Micro-Annulus Crossover System

WireGLvalve300

Wireline Gas Lift Valve

A horizontal micro-annulus system utilizes a crossover flow adapter and a distinct mini wellbore below the packer. This method allows for a deeper point of gas injection, as compared to a conventional gas lift system, usually in a toe-up horizontal lateral. It also does not cause extra back pressure on the formation. This method is better than a conventional gas lift at lowering flowing bottom-hole pressure. An example application might include 2-3/8” tubing above the packer with a crossover flow adapter and 2-7/8” tail pipe below the packer with a 1” or 1-1/4” internal injection string inside the tail pipe. Gas is contained in the small string and lift is annular in the controlled micro-annular area for optimum gas utilization and density reduction.

A vertical micro-annulus system is a good option for wells with low reservoir pressure where it is imperative to isolate gas lift pressure from the perforations. This method provides the ability to manage large casing wellbores with lower amounts of injection gas volumes and pressures. Injection pressure is kept strictly in the injection string and isolated from the perforated interval. The compressed gas moves down the casing annulus and travels through the crossover flow adapter into the 1” or 1-1/4” internal injection string. When the gas travels through the gas lift valve, it exits into the produced fluid, reducing the density and delivering the production to the surface.

MicroAnnulus Crossover System

Increased Annular Velocity System (IAV)

ConvCheckVal300

Conventional Check Valve

The horizontal IAV system provides tubing and gas lift valves that are above a packer, along with a properly sized injection string with internally mounted gas lift valves below the packer. It is imperative to use the proper size tubing and injection string to keep unloading velocities above critical rate and successfully keep liquid off the reservoir. To guarantee the preservation of adequate flow velocity throughout the entire length of the well, acceptable compression must be accessible at the surface for the proper amount of injection gas.

The vertical IAV system creates the ability to reduce the cross-sectional area of flow from larger casing wellbores, along with reduced density of the hydrostatic fluid on the perforations and the formation. The compressed gas moves down the tubing/casing annulus above the packer, through the crossover adapter assembled to the packer and into a dead string of tubing that also serves as an area for compressed gas to travel down and stay separate from the flow area. The gas then leaves the gas lift valves that are placed at various points in the dead string tail pipe and combines with produced fluid and gas in the annulus. Injection gas pressure is isolated from the perforated interval and kept in the injection string. Fluid and gas flow up through the crossover flow adapter, back into tubing flow above the packer and then to the surface through the production tubing. This application is a great choice if low reservoir pressure is present and it is imperative to isolate the gas lift pressure from long perforated intervals. Beneath packer gas lift requires no alterations to the wellhead and installation is simple.

IAV Diagram

The vertical IAV system creates the ability to reduce the cross-sectional area of flow from larger casing well bores, along with reduced density of the hydrostatic fluid on the perforations and the formation.