Maximize Production, Minimize Gas Locking with XCEL VSD

Stark Kremeier

Maximize Production, Minimize Gas Locking with XCEL VSD

 One of the most common ESP issues involves the need to quickly resolve gas locking. While some formations are more challenging on this issue than others, gas locking can happen anywhere, at any time. InstallingExtract Companies’ XCEL Variable Speed Drive (VSD), along with Permanent MagnetMotors (PMMs) instead of an outdated switchboard with an induction motor, gives a producer the tools necessary for solving gas locks quickly, efficiently and automatically.


The Issue

Gas locking in an ESP can occur in several ways.Sometimes there is just a small gas bubble that quickly dissipates on its own.Here, the XCEL’s algorithm is trained to ignore this small burp and continue as normal. Sometimes a larger pocket of gas enters the system, raising the intake pressure and thereby pushing all the fluid above the ESP’s intake.

Using the lightning-fast information processing abilities of machine learning (ML) and artificial intelligence (AI), the XCEL VSD relies on pre-set algorithms to detect — and solve — the most common gas locking issues. It does this in either of two ways: with a single-step solution or a multi-step solution.


The Single-StepSolution to Gas Locking

 A gas pocket, which blocks liquid from entering the intake, will either spike the ESP’s intake pressure or drop the pump’s current load(the latter depends on the pump’s speed). An algorithm in the XCEL can detect the gas lock and act. The most common option involves a single step.

Once the XCEL VSD detects a drop in the ESP’s current draw, signifying a gas lock, the preset algorithm can slow the pump to a predetermined level of 40 hz, for example, to cool the motor. After a preset interval, the XCEL will quickly return the ESP to its original speed. This creates a bounce in the tubing, causing the fluid to drop out of the pump, flushing the gas out of the pump and breaking the gas lock without further intervention in most cases. It also quickly restores the flow of oil back to normal.

Alternatively, with a 60 hz switchboard, the only options are to stop the pump, which means a loss of production during that downtime, or to hold more back pressure on the tubing.


The Multi-StepSolution

 In this case, after the XCEL detects the gas lock situation, it toggles the ESP through three different speeds for a set amount of time before returning it to its preset frequency. The purpose is the same — to bounce the tubing and flush the gas out of the pump to break the gas lock.


PID Integration

The XCEL VSD offers other options beyond preset frequencies. The XCEL can work in tandem with a Proportional IntegralDerivative (PID) loop to maintain a certain intake pressure. When a gas lock occurs in that situation, the algorithm can take control from the PID loop, execute its frequency steps to clear the gas lock, then return control to the PID.

ExtractCompanies’ XCEL VSD has options for detecting and quickly solving gas locking, along with its ability to adjust pump speeds to match a well’s decline curve, when matched with a PermanentMagnet Motor (PMM) ESP —click HERE to learn more. These features combine to increase production, reduce well-servicing expenses and lower energy costs.

Because of this, producers are installing PMMs and XCEL VSDs in increasing numbers. To learn more about how you can improve your company’s bottom line, contact us.

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