Oil & Gas
Safe, non-polluting gas and vapor management: vacuum and compressor systems can handle saturated inlet gas streams, explosive gas mixtures, dirty abrasive gas mixtures and unpredictable streams that change with process variables.
In the oil & gas industry, vapor recovery is the process of recovering stock tank hydrocarbon vapors either in upstream production or downstream refining where the vapors are normally vented to atmosphere. Vapor recovery can be achieved by pulling vacuum and thus, compressing vapors from stock tanks. By using liquid ring pumps, Hexane vapors can be recovered, liquefied and then reused. Using a rotary vane compressor in this application or process includes separating the condensable gases via a separator and compressing the reclaimed gas into a sales line for distribution sales.
Flare Gas Recovery
Flare gas recovery can be described as the sewage system of a refinery or gas recovery at a production site. It is normally considered waste gas due to the composition of the gas. Since these are undesirable HC gases, these gases are generally sent to flare to be burned off.
Often times, there is usable, good-quality gas with some residual BTU's value being burned off. This gas, once separated, can be recovered and compressed from low-pressure compressors to large pipeline compressors. These normally reciprocating compressors ultimately compress the recovered gas to a gas plant for processing and may be used for cogeneration.
The process of "waste to energy" is applied here, as it is economical to recover the majority of the flared off gas and utilize it as a source of energy and revenue. Minimizing the flaring of gas is both an environmental and lost revenue issue and opportunity.
Field Gas Boosting
Field gas boosting is the process of boosting low-pressure gas from the wellhead to a high-pressure pipeline. The wellhead gas pressure, below atmospheric pressure or at a relatively low positive pressure, will require a vacuum pump or a low-pressure compressor to extract the gas and to boost it to 15 to 30 PSI above atmospheric pressure. A rotary-vane, or a liquid ring vacuum pump or compressor is used as the first stage. Any of these then deliver the gas to the second stage high-pressure compressor. The high-pressure compressor, usually a rotary-screw or reciprocating compressor, delivers the gas to a gas processing plant via a pipeline.
Fuel Gas Boosting
This application involves the utilization of a booster compressor to provide natural gas to a natural gas engine that may be utilized in the gas recovery or compression process.
Enhanced Oil Recovery
Enhanced oil recovery is an upstream process, which includes pulling a vacuum on an oil well to relieve pressure on the well. This allows the oil to flow more freely, increasing oil production. This application may also include associated gas, which is merely the inclusion or recovery of gas at the annulus of the well, with the oil being recovered and the separation of the oil/gas via a separator at the point of recovery, normally at the surface of the well.
This upstream process involves the vacuuming or compression of several wells, where the gas is gathered into a single manifold or a header bar. The process, usually completed with vacuum pumps and or low-pressure compressors, compresses the gas into high-pressure pipeline compressors, normally reciprocating compressors, to be taken to a gas plant for processing.
Coal-Bed Methane Gas Recovery
This application is found in coalmines where two forms of gas may be produced. One gas is from microorganisms feeding off the coal, and the other gas is from gas deposits in the mines. By drilling into the coalmines, and locating sufficient gas deposits, the gas can be recovered through vacuum, depending on suction and discharge pressures at the well head. The gas, once recovered by the low-pressure vacuum, is then compressed by high-pressure compressors to a pipeline for processing or used for cogeneration, etc.
Normally the methane gas recovered is very clean but significant quantities of liquids may be entrained in the gas. This gas is recovered for a number of uses, including cogeneration and gas plant processing for redistribution of sale.
Landfill Gas Recovery (Bio-Gas)
This application includes the recovering of gas resulting from the decomposition of waste materials, which are generally located in landfills. Agricultural waste is also subject to decomposition, and gas may also be recovered from the decomposition of this waste.
The process in a landfill is very basic in nature. In short, a hole is drilled in various points in a landfill site and perforated pipe is inserted into the drilled hole. A vacuum pump or, if above atmosphere pressure, a compressor is used to compress the gas and to deliver it to a natural gas engine used to drive a generator. In turn, this gas is used to generate electricity. The gas may also be used to feed boilers or furnaces. It may even be cleaned up, and the dirty gases removed to sell for industrial plants, etc.
Digester Gas Recovery (Bio-Gas)
Human or industrial waste material is treated by depositing it into a sludge or holding tank for decomposition. By using a compressor to compress the gas into a sparging unit piped into the tank, the gas serves to provide heat and to agitate the slurry, keeping it in suspension, and also activating the bugs to eat the decomposed material or sludge. A compressor is also used to recover this gas and to compress it to a natural gas engine, which is used to drive a generator to produce electricity for cogeneration or to feed boilers, furnaces, etc.
Tank Cars Unloading
This application involves the unloading of tank cars containing liquid such as butane, propane, etc. A rotary vane compressor is connected via a four-way valve with the sphere, rail tank car, and unloading KO drum. Initially the compressor takes the vapors from the sphere and pressurizes the tank cars, forcing the liquid from the tank car to the storage sphere. Once the unloading of liquid is complete from rail cars to the sphere, the vapor recovery begins by opening of the four-way valve towards the tank car and removing residual vapors and vaporize any remained liquid from the rail tank car until slight negative pressure of -1 psig is achieved. The rail tank cars are then blanketed with inert gas and returned for reloading with butane or propane.