Both offshore oil and gas platforms and floating production storage and offloading (FPSOs).Oil and gas extraction units away from land. During its production, its production equipment may leak flammable and explosive gases or vapors. When these gases or vaporizeWhen the concentration of steam in the air reaches a certain value, an explosion and fire accident may occur at any time, which threatens people to participate in the safety of equipment. At the same time, inDuring oil and gas production, a large amount of sludge is extracted from the seabed, which contains high concentrations of hydrogen sulfide gas, which is potentially harmful to the lives of operatorsIn the threat.
Both offshore oil and gas platforms and FPSOs have the same operating environment characteristics:
※ Small work space and high risk: Compared to oil refineries and LNG storage and transportation on land, offshore oil and gas platforms and FPSOs have the operating spacelimited, while leaked flammable gas and hydrogen sulfide gas are both highly concentrated gases. Once a leak occurs, it is often easy to lead to explosion and poisoning of personnel.environmental pollution is much more dangerous than on land.
※ Large temperature changes, high humidity: The temperature difference between day and night at sea is large, in the Arctic waters, the temperature can be as low as minus tens of degrees, and in the equatorial waters,The sea temperature can be as high as 60~70°C. At the same time, the humidity at sea is much higher than in the interior. In this working environment, ordinary equipment will soon beCorrosion or damage.
※Logistical supply and maintenance difficulties: Offshore platforms and FPSOs are often far from land, and their work, living and storage space are very limited. oneIn the event of an accident or equipment damage, its limited storage can hardly meet the needs of replacement and maintenance.
Arguably the application environment on offshore platforms and FPSOs is the most demanding challenge for field instrumentation.
*Flammable gases: mainly methane, propane and other gases. The leakage of combustible gases occurred on offshore platforms and in various rings of FPSO productionNodes can occur, and the possibility and danger of leakage are the greatest
※Hydrogen sulfide gas: Hydrogen sulfide gas is brought up with the sludge on the seabed, so its leakage exists in drilling rigs, wellheads, sludge tanks and other equipment.
※ hydrogen: All electrical equipment for offshore platforms and FPSO are powered by 2 channels: one for working and one for UPS. Therefore,
On offshore oil and gas platforms and FPSOs, there are dedicated battery rooms for storing the large quantities of lead-acid batteries required by UPS. And in lead-rate batteriesThe electrolyte undergoes a chemical reaction to produce hydrogen, resulting in hydrogen leakage.
The number and location of combustible gas detectors are determined by the characteristics of offshore platforms and FPSO facilities. Therefore, it is necessary to monitor the first combustible gas detectorThe large-scale three-dimensional space is often not a few monitoring points to ensure its working effect, and its layout is based on the principle of flammable gas probeThe detector is arranged in all equipment and places where flammable gas leaks and potential flammable gas accumulates; At the same time, the regional assessment determines the required detectorOverride type to determine the layout of the gas detector. The specific arrangement should consider the following points:
1. It is necessary to understand the characteristics and potential dangers of offshore oil and gas production processes, and fully consider the possible construction of personnel, equipment, environment, etcThe focus is on finding out what possible leakage points are in the production equipment that needs to be monitored:
a) Place the detector at the sealing and sealing gland of high-pressure equipment, compressors, vacuum pumps, reactors, and storage tanks that are prone to leakageAmong the possible pathways of potential flammable gas release, and a certain distance is achieved by moving the detector closer to the potential flammable gas release sourceimprove the sensitivity of the detector;
b) When determining the specific location of the detector at the air intake duct opening, it should be noted that some detectors will be sensitive to position and airflow.
2. According to the dominant wind direction of the place, the possible circulation phenomenon and upward trend of the air flow, and the habit of the natural flow of air in the computer roomchannels, etc., and judge the leakage direction of flammable gas when a large amount of leakage occurs, the detector should usually be installed in the downwind direction.
3. According to whether the density of the leaking gas is greater than that of the air, and combined with the air flow trend to comprehensively complete the detector arrangement. Yes for releaseIn the place where the gas or gaseous mixture is with air, the detector should be arranged close to the operating surface; For flammable gas when releasedWhere the body or gaseous mixture is lighter than air, the detector head should be placed above the device or area being protected. At the same time, inWhere possible, the detector should be positioned above structural steel, pipelines, and equipment that would alter the way air flows.
4. Study whether the leakage state of the leak point is micro-leakage or jet-like. If it is a slight leak, the position of the point should be closer to the leakage point; Such asIf it is a jet leak, it should be slightly further away from the leak point.
5. For indoor installations with required area coverage, they should be based on the heating and ventilation system and the potential release of flammable gas characteristics relative to theThe floor and the operating surface are arranged with detectors, and the maximum spacing of detectors is 13~15m.
6. For areas with a large outdoor area, the key leakage points can be arranged separately and uniformly arranged. Probe in flammable gasThe detector group should be used to vote on the premises where the action of the instrument can cause shutdown. When evenly arranged, the distance between the monitoring points should be10~20m, and the installation density can be appropriately increased or decreased according to the safety requirements of the production process.
7. For the parts of the indoor ventilation that are not smooth, the place where the gutter is prone to the accumulation of flammable gas, and the underground cable trench leading to the control room on site, there isDetectors should usually be fixed in places where flammable gas tends to accumulate on a regular basis or in abnormal production situations, such as sewage ditches that seal the coverFix in those dead spots where there may be gas leakage.
The structure diagram of a typical gas detection system on offshore platforms and FPSOs is as follows:
As shown in the figure above, safety requirements on offshore platforms and FPSOs are higher than in other industries. Therefore, the controller should adopt SIL3 evenFGS control system with SIL4 safety class. The entire system is also designed in accordance with SIL3 safety ratings. All the detectors on the scene were exhaustedSelect high-safety equipment, directly transmit the 4-20mA signal to the FGS controller, and the FGS system will collect and calculate the detection value.When an alarm occurs, use alarms, linkage, etc. to eliminate danger.
The gas detector and gas alarm control system used on offshore oil and gas platforms and FPSOs have the following features:
◆ Fast response speed and high safety level of equipment and system.
◆The equipment has stable work, long service life and low maintenance.
◆The on-site gas detector is made of 316 stainless steel, which has strong resistance to temperature and humidity and corrosion resistance.
Honeywellgas detector for offshore oil and gas platforms and FPSOs
◆For combustible gas detectors, two detection principles are selected:
※Detection principle of point infrared absorption compensation.
※ Open-circuit infrared detection principle.
Optima Plus Combustible Gas Detector:
The Optima Plus combustible gas detector uses dual light source, dual beam IR compensated detectionprinciple, with fast response speed, high accuracy, low maintenance and long service life (typical service life of 15 years)and other advantages. OptimaPlus is made of full 316 stainless steel for good corrosion resistance. Optima PlusIt also has SIL2 safety level certification, as well as BV, ABS and other multinational classification societies certification, which is a highSafety-rated gauges. Optima Plus is widely used in a large number of offshore oil and gas platforms and FPSOs.
Apex Toxic Gas Detector:
Apex toxic gas detector is constructed with full 316 stainless steel for good corrosion resistance. Apex CollectionWith the structure of a universal transmitter + smart sensor, the patented HeartbeatTMtechnology, to makeMaintenance on site is minimized. At the same time, Apex has 27 smart sensors that can be used for detection18 different types of gases (each also has a different Measuring range). Apex is also widely cited inOffshore oil and gas platforms and FPSOs, mainly used for the detection of hydrogen sulfide and hydrogen.
XCD Flammable/Toxic Gas Detector:
As Honeywell's next-generation universal gas detector platform, XCD has a variety of detection andIntelligent sensors can be used to detect all kinds of flammable gases and toxic and harmful gases. XCD equipmentThere are two materials of aluminum alloy and 316 stainless steel shell, unique three-color backlit LCD display function,Standard relay signal output, patented SurecellTMtechnology, which makes XCD applicable