Plunger lift systems improve and prolong the productivity of natural gas wells by removing the liquid layer that periodically blocks the flowing gas. An explosion-proof pressure transmitter like the E-10 plays an integral role in keeping wells productive and operating safely.
Natural gas is used in countless homes and in the manufacturing of chemicals. While renewable energy and hydrogen are slowly replacing natural gas (methane) as fuel and feedstock, this abundant and economical hydrocarbon is still a vital part of global economies.
Plunger Lift Systems and Wellhead Pressure Monitoring
Solar-powered plunger lift system
When a natural gas well is no longer as productive as it once was, due to a liquid layer (or slug) preventing the gas from flowing freely, a plunger lift system installed at the wellhead of a vertical well can clear the blockage. This system is simple and effective:
- An electronic controller continually monitors the flow of gas. When the flow slows down, the controller closes the wellhead’s valve. This action causes the plunger to fall through the slug layer.
- Pressure builds within the closed well. When the pressure reaches a preset level, the valve reopens. This sudden change in pressure pushes up the plunger to clear away the liquid slug, and the gas begins to flow freely again.
Mounted at the wellhead, pressure gauges and pressure sensors are essential for monitoring the gas pressure of the bore hole, casing tube, various points of the plunger lift system, and other critical points. Since natural gas and fumes are potentially explosive, the electronic instruments used at the wellhead must be intrinsically safe or explosive-proof. WIKA’s E-10 pressure transmitter with flameproof enclosure is ideal for wellhead applications.
Explosion-Proof Pressure Transmitters for Wellhead Applications
Approved as explosion-proof and flameproof by FM and CSA, model E-10 is a highly accurate and reliable pressure transmitters for wellheads and other oil and gas applications – upstream, midstream, and downstream – thanks to the following features:
- Measures gauge pressure, absolute pressure, and vacuum
- Gauge pressure ranges from 0 … 5 psi to 0 … 15,000 psi
- Very high resistance to vibration and pressure spikes (high overpressure limits)
- IP 67 (NEMA 4x) for superior protection against moisture
- Designed to withstand sulfide stress cracking and other effects of corrosive gases (reference materials meet NACE MR 0175)
- High accuracy of ≤ 0.5% thanks to active temperature compensation, even with strong fluctuations in the ambient temperature
- Analogue signals from 4 … 20 mA to a low-power version of DC 1 … 5 V
- FM and CSA approved as explosion-proof for classes I, II, III div. 1 hazardous areas; ATEX and IECEx approved as flameproof for II 2G Ex db IIC T6…T1 Gb
In explosion-proof installations, the cabling must be run through a rigid conduit.
The Difference Between Cable and Flying Lead Wiring Options
The E-10 explosion- proof pressure transmitter comes in two versions: cable (left) and flying lead.
All Class I Division I explosion-proof installations require cabling to be run through a rigid conduit with conduit seals. These installations must have a conduit seal within 18″ of the cable termination point in the transmitter.
- For the cable version, users have to add this initial conduit seal themselves.
- For the flying lead version, the conduit seal is built into the electrical connection, so users do not need to install one.
The conduit seal installation process is not trivial, as it takes expertise, specialized materials, and labor. Furthermore, the seal material can be toxic. So, even though the cable version of the E-10 costs less initially, most users save money and time by getting the flying lead version.
WIKA, Smart in Sensing for Wellhead Pressure Monitoring
In addition to wellhead pressure monitoring and control, the E-10 pressure transmitter is found in other upstream oil and gas production applications, such as pipeline monitoring, produced water measurement, and fracking trucks. For more information about safe and accurate wellhead pressure monitoring and control, contact the product specialists at WIKA USA.
Product mentioned in this article:
• E-10 pressure transmitter with flameproof enclosure