Wireless Alarming Keeps Revenue Flowing Through the Pipeline

In the late 1980s, a geological formation known as the Antrim Shale centered on Northern Michigan was found to contain natural gas deposits. Currently, the Antrim “play” is the most active gas field in Michigan with around 7,400 wells.

Currently, the Antrim “play” is the most active gas field in Michigan with around 7,400 wells. Although a long way from oil and gas giants such as Texas, in 2002 Michigan produced 215.5 billion cubic feet of natural gas. This ranks Michigan as the twelfth largest natural gas producing state in the nation and tops among the Midwestern states.

Go with the flow: Gas and oil production involves millions of dollars tied up in pumps, pipelines and associated infrastructure. With a huge investment in plant and equipment, coupled with high operating costs, profitability is highly dependent on keeping the fossil fuel—whether it be oil or gas—steadily flowing out of the ground. Most oil and gas fields are comprised of hundreds of remote unmanned wells spread over large geographical areas. Experience has proven that even a modest investment in wireless alarming can quickly pay for itself by ensuring that the gas (and hence, the cash) keeps flowing. Based in the City of Gaylord, Gaylord Communications & Electronics is located smack dab in the middle of the Antrim Shale. With many petrochemical companies operating gas fields in the local area, it’s not surprising that the two-way company was quick to use its expertise to serve the needs of the largest player in the local economy. “Most of the gas fields are located within 75 miles of Gaylord,” explains company president Wayne Miller. “They haven’t done much oil drilling in the last ten years, because natural gas has taken over.”

Drilling for dollars: The gas deposits are discovered at much shallower depths than the oil deposits. A typical oil well goes down a mile, whereas a gas well may only reach a thousand to fifteen hundred feet. High-pressure transmission pipelines are used to transport the gas to natural gas distribution utilities, which then deliver the gas to customers. Strategically placed compressor stations pump product into the lines. The gas product is obtained from up to 40 wells situated around the compressor station. The engines driving the compressors are generally gas burning, using a small percentage of the gas passing through the station to compress gas coming into the station to a higher outlet pressure. The value of the gas flowing through the pipeline is measured in thousands of dollars per hour. Consequently, if a compressor stops running due to a mechanical break down or other reason, the cost of lost production to the gas company mounts rapidly.

Sentry duty: In response to the gas companies’ needs, Gaylord Communications came up with a compressor alarming system using the cost-effective Zetron Model 1516 SentriVoice. The SentriVoice is a wireless voice alarm reporter that monitors contact inputs and, upon sensing an alarm condition, transmits voice messages over a radio or public address system. If desired, users can then respond to alarms by radio to control lights, pumps, and other control equipment via the Model 1516’s integrated output relays. This simple but effective solution works so well that Gaylord Communications has installed SentriVoice alarming systems for a half-dozen local gas companies. “We have approximately two hundred out in the field,” says Miller. “We use Model 1516s along with two-way radios and solar panels, because most of the gas compressors are in places where there is no electricity or telephone service.”

Frozen no more: After a well is drilled, a significant amount of brine (salty water) comes up with the gas. Before it can be used, the gas must be separated from the brine water and dried, after which the brine is pumped back into the ground. All that water is a real problem during the Michigan winter, when average temperatures both day and night may remain below freezing. “This morning it was ten degrees below zero,” Miller continues. “If a compressor goes down and stays down for any length of time it will freeze up. It may then take the gas company workers a day or two to thaw the facility out and get it back on line. In the meantime they could lose hundreds, even thousands of dollars per hour in sales. If a compressor goes down, an oil pressure switch on the oil line activates the SentriVoice, which sends out a voice alarm such as ‘The Boughner Compressor is down. Send personnel…” During working hours, maintenance personnel in the field receive the voice messages on their mobile radios. However, should a compressor fail after-hours, a local answering service fills in. The answering service takes over in the evening and monitors the SentriVoice until gas crews are back on the job the following morning. If the answering service receives an alarm call, it’s their responsibility to look up the personnel responsible and dispatch them to the site.

SentriMax provides quality control: For us air-breathing humans, having lots of oxygen is a good thing. But when there’s too much oxygen in a natural gas pipeline, that’s a bad thing. Currently, Wayne Miller’s company is in the middle of upgrading a gas customer’s SentriVoice alarming system to also monitor for excessive oxygen (O2) levels. This customer’s alarming system is slightly different than the others in that it uses a Model 1516 SentriVoice at each gas compressor site to send a DTMF string via radio to a Model 1550 SentriMax located at the main office. The SentriMax then uses its dialup feature to report a problem in the form of a voice message. Answering service personnel then look up the appropriate on-call personnel and dispatch them to the site. “This particular gas company is now spending $2,400 plus installation per compressor site to add an oxygen sensor/computer. The computer provides a contact closure to the SentriVoice when the oxygen level exceeds 5 PPM [parts per million],” Miller says. “We have thirty sites at which I am just now starting to add O2 sensors and reprogram the Model 1550 to accept another input. We will use two discrete DTMF strings: one to alarm if the compressor system is down, another to alarm if the oxygen level is too high.” Miller explains that the public utility purchasing gas from the supplier regularly monitors gas levels for excessive levels of 02. If the gas does not meet a quality standard, it could result in a loss of revenue to the gas producer. For this reason, the gas production company expects to quickly recoup its investment in alarming by ensuring the steady flow of a high quality product.

Simple and cost-effective: Wayne Miller says that this is a simple application that barely scratches the surface of the capabilities of the SentriVoice and SentriMax. But as Miller points out, when you have a solution that’s reliable and works, there’s no reason to spend more money on something more complicated. Article provided by Zetron.