With performance monitoring all the data available on this control panel is available through an Internet Web site. (Photo courtesy of Compression Consulting LLC)
The economic benefits for efficient compressor operations have never been greater than they are today. High commodity prices for natural gas increases revenues for the gas producer, but the higher price for natural gas also makes the cost of equipment downtime more significant.

With the increasing cost of deploying a technician to the site due to labor cost and vehicle operating expenses, minimizing the technician’s trips to the site becomes an objective of the compressor operator. Most compressor rental companies have dropped “first response” as an offering for their customers because of this escalating cost, which easily exceeds US $100 per hour. First response means that when the compressor goes down the lessee has to go to location first, determine the down fault and attempt to restart the compressor. Only if the fault is mechanical in nature or the operator can not get the compressor started will the rental company mechanic be called out.

The mandate today to compressor rental companies by producers and gatherers is to maintain as close to 100% equipment utilization as possible. Today, 100% utilization is defined as continuous runtime at peak equipment performance.

The compressor rental company may not share the same priorities as the producer. The compressor rental companies do want to provide good equipment and consistent run time to their customers, but their customers have exponentially more to lose if the compressor is not performing to its design capabilities. In the current compressor rental market, that has seen compressor rental rates increase by as much as 50% in the last 3 years. It is a sellers market for compression and compression services.

Alarm economics
The cost of an alarm device and the related monthly fee for third-party services for a compressor-down notification is minimal compared to the potential for lost revenue associated with not selling gas. At the current market price for natural gas a compressor application moving 1 MMcf/d of gas costs the field operator more than $2,000 in lost revenue for each 1% of compressor downtime (7.5 hours) per month. Averaging the delay in a unit down 12 hours per event, the lost revenue for that single event is over $3,400.

Payback for an alarm system will be met with the very first response to an alarm. Most compressor rental companies provide an on line time guarantee of 95% to 98%. Downtime for determining any credit begins when the compressor company is notified that the compressor is down. A rental compressor designed for 1 MMcf/d using 300 hp may rent for $7,000 per month with maintenance. A dismal run time of only 90% will may result in a credit of $350 to the producer by the rental company while the producer loses $6,000 in revenue.

Performance monitoring
With the data review tools available through a network- or Internet-based monitoring solution, performance data can be converted into usable, productive information.
Remote monitoring of compressor and production equipment performance data has been proven to reduce downtime and operating expense by providing the technicians with warnings as to pending failures which often result in a catastrophic loss. Compression equipment components usually provide evidence of a pending equipment failure via changes in the performance data. If this evidence is recognized by anyone in the organization of the producer or the rental company, the failure may be minimized or completely averted.

Economics
As with the economic justification of compressor status monitoring (off/on alarm) the economic justification for expanded performance monitoring can be made. The push-back from the purchaser is not likely to be the cost of the Internet monitoring service or the communications but the initial installation cost of the sensors and other electronic components on existing field units. Installation of performance monitoring equipment can cost as little as $2,000 but can go as high as $10,000 to retrofit an older compressor package.

For example, look at an application with a gas engine-driven compressor at 3,500 hp compressing 20 MMcf/d of natural gas into a sales line. In this example, an engine main bearing failure will cause the exception alert. This pending failure can be detected by an increase in the bearing temperature and increasing engine vibration. Having received an exception alarm notification, the operator can do a correlation analysis between various data points before concluding that a pending failure is imminent and call the field to have the unit shut down. Failure to respond proactively could result in a damaged or broken engine crankshaft with repairs costing $100,000 and the downtime costing almost $1 million per week in lost revenue for the producer. In this example the benefits to the compressor rental company and the producer will easily justify the expense of the system.

Producer perspective
It is in the producer’s economic interest to have remote monitoring on the equipment, even to the extent that the producer is responsible for the cost of installation and monthly service charges. For the rental company it may be difficult to justify spending money on monitoring if it only sees it as a benefit to the customers and not its own financial performance. It is up to the producer/gatherer to make sure that the optimum performance of the compressor is being delivered by the compressor rental company.

Rental company perspective
Though the rental company does not have the economic incentive of the producer, the potential cost savings in labor and direct expenditures can be significant. Using remote monitoring effectively can provide management by exception for the rental company the same as it does the producer or gas gatherer. Remote monitoring can provide oversight to rental companies as to how their customers are operating the equipment. These compressor companies have a tremendous investment in their equipment.

The handicap of the equipment owner in investigating the cause of a major and expensive failure is knowing how the equipment was being operated prior to a failure. Pumpers have been known to adjust the safety shut-down settings on compressors to minimize their first response call-out responsibilities. A safety shut-down such as low suction pressure that has been tampered with can be reset after the unit is down to provide the pumper with plausible denial when the compressor craters due to excessive rod load on the compressor frame. If the company leasing the compressor was using remote monitoring, it could confirm that the equipment was being operated outside of its approved design range. When an expensive failure occurs, the rental company will have the evidence to go back to the customer for reimbursement of the repair cost due to the customer’s questionable operations practices. The condition and maintenance of the equipment is not the priority of the producer-gatherer’s field personnel. Their directive to maximize gas sales through compressor run time may result in improper operation of the equipment. If the compressor goes down due to mechanical issues, then it becomes the problem of the compressor rental company.

Summary
The ideal situation will be the rental company and the producer agreeing to the installation and utilization of performance monitoring and sharing the cost associated with its implementation.

Comments