How does Natural-gas processing works

Posted by alvina on July 28th, 2019

Natural-gas processing is a complicated manufacturing process that is designed to purify raw natural gas. This is done by means of sorting out the dirtiness, different non-methane hydrocarbons as well as fluids so as to produce what is called dry natural gas pipeline quality . The process starts at the well head where the raw natural gas composition hauled out from the generating wells usually depend on the type, the depth, the site of the underground deposit as well as the geology of that particular area. Natural gas and oil are normally found together in a similar pool. The natural gas that is produced from oil wells is commonly categorized as associated-dissolved. This means that the natural gas is combined with or it is liquefied in crude oil. The production of natural gas without any connection with crude oil is categorized as non-associated.

The natural gas used by consumers in its final state varies greatly than the natural gas underground. The last product encompasses nearly clean methane, although raw natural gas has a mixture of dirtiness. These impurities consist of hydrogen sulfide, carbon dioxide, water vapor, nitrogen, oil, hydrates in addition to heavier hydrocarbons that mostly consist of ethane, butane, propane and pentanes. Whereas several processing is done at the site of the well, the total processing occurs at a processing plant. Eradication of all or majority of the impurities is necessary before going into the pipeline. Even though the processing has a number of steps that should be followed, there are four major processes: oil condensate plus water removal, carbon dioxide along with hydrogen sulfide removal, dehydration and finally the NGL removal.

The initial step in natural gas processing is done by first removing oil, water as well as condensates and this step is usually done at the site of the well. Initially, the workers use heaters and scrubbers to avoid the gas temperature from falling too low and also to take out the large particles of impurities correspondingly. Next, by using the conventional separator, the oil is separated from the gas. This separator is made up of a closed boiler and its work is to separate the solids and the liquids through the force of gravity. In a situation where gravity fails to separate the liquids, the separators make use of pressure in order to cool the gas. It then goes through a high-pressure liquid, at a lower temperature so as to knockout any residual oil any remaining water

After the oil, water along with condensates has been taken out, hydrogen sulfide and carbon dioxide should be also be removed if they are there. This step is called sweetening the gas, as a result of sulfur’s smell and this step is very significant since hydrogen sulfide is very dangerous, very corrosive and even deadly. Once carbon dioxide and hydrogen sulfide has been taken out, the natural gas should be dehydrated. Dehydration is essential in removing the intemperance water that form corrosion, hydrates, freezing problem and fails to meet with the requirements of the pipeline. Water is taken out in form of water vapor and this can be done by adsorption or absorption.