The Mechanical Shaft Lock Proves Extract Is A Leader In Safety.

Hunter Cates

Extract’s Mechanical Shaft Lock for Permanent Magnet Motors improves safety, increases efficiency, and positions us as a leader in safety and innovation.

Producers switching from induction motors to permanent magnet motors (PMMs) are saving thousands in operating costs, while being more environmentally friendly by using less power.

Given the unique requirements of the PMM, operators are becoming more safety conscious as well.

Every electric motor can also function as a generator if its shaft is turned by external forces, such as the downhole pressure on an ESP. While the voltage generated in induction motors is insignificant, PMMs can generate significantly larger amounts and in rare cases, even lethal amounts of voltage.

Producers want to take advantage of PMMs ability to dramatically improve their operations’ performance — but no boost in efficiency is worth safety risks.

Clearly a solution was needed. While there have been various safety measures and procedures in place to decrease the danger, none has completely eliminated the possibility of rotation, and with it, the PMMs’ greatest threat.

That is, until now.

The Mechanical Shaft Lock (MSL) for PMMs is a game-changing innovation that increases safety and efficiency, protecting worker’s wellbeing and operator’s investments.

The capabilities of MSL have been demonstrated in a study published by Extract team members Ken Saveth, Charles Booth and Mauricio Oviedo titled: “A Failsafe Method of Preventing Voltage Generation During Installation and Pulling of ESPs with Permanent Magnet Motors.”

Saveth, Booth, and Oviedo are presenting the team’s findings at the SPE Electric Submersible Pump Symposium and the SPE Annual Technical Conference and Exhibition in the fall of 2023.

These presentations will show the world what we at Extract already know — the MSL improves safety and positions us as the undisputed leader in safe PMM operations.

How the Mechanical Shaft Lock works.

“There is always a risk for unplanned rotation with an electric motor,” said Charles Booth, Extract’s Director of Field Service and Operations. “We had to be able to come up with a way to protect people, besides just relying on their PPE.”

“You can’t see or predict when that well kick is going to happen,” explained Ken Saveth, Extract’s Director of Reliability. “So, this system is in place right from the beginning, allowing you to design out the possibility of injury or worse.”

“Electricity is a hazard you can’t see,” said Booth. “So, we engineered the hazard out, with the PPE as a redundant last line of defense, not a first line of defense.”

With existing safety systems like shunting, the potential for unplanned rotation (and large, unexpected surges in electricity) still exist. Asking operators to simply rely on their PPE in the event of an unplanned rotation is unreasonable and unsafe. Instead, the MSL prevents unplanned rotation from happening in the first place.

The mechanical shaft lock mechanism uses shear pins that physically lock the shaft to prevent it from rotating. Only the mechanical motor horsepower has enough force to shear the pins loose; downhole pressure is not enough. Once the motor is powered, the force generated automatically unlocks the shaft to allow for the normal operation of the ESP. Utilizing a PMM mechanical lock mechanism stops the shaft from rotating, while installing or pulling a PMM-ESP string provides a failsafe method for preventing potentially fatal conditions.

“Shunting will still allow rotation if the fluid force is strong enough, which is like driving your car with your foot hovering over the brake,” said Booth. “The MSL actually locksthat shaft in place. With the tubing block and shunting, rotation could still happen. With the MSL, it’s impossible. No shaft rotation, no voltage generation.”

The Mechanical Shaft Lock proves Extract is a leader in safety.

Booth has been in the business for 25 years. Saveth, for 40. Yet despite each man working decades for various companies around the world, neither has ever experienced a collaborative, people-first culture quite like Extract. They believe that same culture is the reason why Extract was able to develop the MSL in the first place.

“You actually have a voice here. It’s a very open environment, where everybody’s opinions are heard, and people are encouraged to speak up,” said Booth. “That 100% makes the work better, and it’s why we were able to focus on the MSL.”

“This work hasn’t happened elsewhere,” said Booth. “We took that next step. We are actually able to develop and deploy things like this quickly because of the support we have. Everybody can say they’re innovative at technology, but we have taken that extra step to be innovative at safety as well. Usually people care about efficiency and runtime. We focused on safety in a way I don’t think any other company is doing.”

Booth noted that Extract will not be removing any of the PMM’s current safety devices, but instead will be adding the MSL to them. In fact, every one of Extract’s PMM customers is required to have at least two-out-of-three safety devices (tubing block, shunt, MSL), in addition to PPE.

Booth and Saveth are proud to share their data with the public, and even more proud to offer the MSL to customers.

“There may be skepticism at the start,” said Saveth. “But looking at the data, that skepticism will go away. We want customers to say: ‘Oh my gosh, I really do have something available to me that I can run PMM safely.’”

“This is something the industry wants because of the power savings you get with PMM,” said Booth. “We want to make a cleaner environment, but we want to make a safer environment too. The tech is there from the green side, but there’s always been that concern on the safety side. Thanks to MSL, you can be environmentally conscious and still do it safely.”

Extract’s presentation on the Mechanical Shaft Lock for Permanent Magnet Motors will be held:

• SPE ESP Presentation: October 2-6, 2023, at The Woodlands Waterway Marriott Hotel & Convention Center in The Woodlands, Texas

• SPE ATCE Presentation: October 16-18, 2023, at the Henry B. Gonzalez Convention Center in San Antonio, Texas

To learn more about bringing Extract’s PMM to your operation, contact us.

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