The oil industry is crucial for our way of life. Time is money, making downtime the enemy. Bonitron offers many solutions for the oil industry that aid in maximizing uptime and reliability for any drive-driven process.
Drawworks and Top Drive/Rotary Table drilling rigs drill holes into the earth in order to extract petroleum. Most of these rigs utilize variable frequency drives (VFDs) to control the raising and lowering of the travelling block (done via drawworks), as well as the spinning of the drill bit (done via top drive or rotary table).
Time is money in the oil industry. The faster the drawworks lowers the drill string back into the borehole after adding an extension, the better. The drill string is dropped and then stopped rapidly before hitting the bottom. This rapid deceleration requires drive overvoltage protection, commonly in the form of a Braking Transistor and Resistor.
A Top Drive or Rotary Table spins the drill string. Drill strings can be thousands of feet in length, so it is common for one end of the string to be spinning faster or slower than the other end (just as if you were to spin on end of a shoe string). Overvoltage protection on the top drive or rotary table is necessary in these cases to control torque on the drill string.
Resistive Load Banks
Pumpjacks are used to mechanically pump liquid from the oil well when the bottom hole pressure isn't strong enough to push liquid to the surface.
Pumpjacks are powered by a prime mover, which in many cases is powered by an electric drive/motor combination. The prime mover drives pulleys that move a pair of counterweighted cranks. The cranks are counterweighted to aid in lifting the string. Regenerative energy is created when the string is lowered (pulls itself) back into the hole. Rigs counterweighted properly may require as little as 5% duty cycle ratings, whereas those not counterweighted well may require up to 30%+.
Bonitron offers Braking Transistors, Resistors, and Line Regeneration units to absorb the excess regenerative energy created on the pumpjack downstrokes. With pumpjacks being counterweighted, it's common for motors to be only 20 - 150HP. Many applications allow the regenerative energy to be placed back on the available AC line, which can be done with our M3345 Line Regeneration units. On remote pumpjacks where no AC line power is available and generators are used, the Transistor is required to protect the generator from energy feeding back into the generator.
Resistive Load Banks
Progressive Cavity Pumps (also known as eccentric screw pumps, cavity pumps or PCPs) act similar to a screw that brings oil to the surface. It is critical for PCP applications to have constant, uninterrupted power. If the drive rotating the screw loses power and trips on an undervoltage condition, the process may experience several hours of downtime and lost production. If the process is pumping oil with high viscosity levels (thick like molasses) than downtime can be even longer, as it is customary to wait for the oil to drain back to the bottom before restarting to help prevent equipment damage. The next page elaborates with a case study and the benefits of matching a Bonitron Undervoltage Solutions with your PCP application.
Variable Frequency Drives (VFDs) are commonly used to drive Electrical Submersible Pumps (ESP), Beam Pumps, and Progressive Cavity Pumps (PCP), which extract oil from the ground.
VFDs on Electrical Submersible, Beam, and Progressive Cavity Pumps are susceptible to voltage sags and reclosure operations (tripped circuit breakers). A short sag or interruption in voltage (less than a 1/10th of a second) is enough to cause an undervoltage trip on a VFD, resulting in minutes or hours of downtime and costly production losses. A typical oil field can see 50 or more voltage sags per year, with 25+% able to trip the drive. Remote applications using reclosure (automatically resetting circuit breakers) to clear temporary faults from lightning, animal, or tree contact, will see more full interruptions in power. During these reclosure operations, the drives will trip — typically resulting in complete field outages.
Bonitron Undervoltage Solutions, including DC Bus RideThru, protect by regulating the pump's drive's DC bus voltage during sags and outages so that the pump will operate without interruption. Case studies show an increase of pump availability from 95.5% to 99.2%, resulting a six-week payback (@ $50 barrel).
A major oil extractor developed an oil field in Venezuela, which included the expansion and reconditioning of their existing 24 kV distribution system to ensure reliable service for the new and existing wells. All of the ESPs and PCPs, and some of the Beam Pumps, are driven by VFDs. Disruption to the PCP drives from voltage sags or reclosure operations resulted in 8 – 16 hours of lost production each occurrence. About 255km of overhead lines results in high exposure to lightning events resulting in subsequent sags and interruptions that cause well-site drives to trip, severely impacting production goals.
A strategy was developed to combine Bonitron RideThru with a reclosure system so that most disturbances would have no effect on production. Bonitron Ultracapacitor RideThru System's energy storage capacity was coordinated with the reclosure settings to allow for single or multiple reclosure operations. The Drive RideThru provided 0.75 seconds (45 cycles) of interruption capability on 60hp PCP drives. (Bonitron offers systems protecting up to 1MW for up to 15 minutes
Resistive Load Banks