Natural gas is present in the fine pores of certain rocks. The depth at which natural gas is found varies from 1,000 meters to several kilometers. Gas is extracted from underground using specially drilled wells, called production wells or exploitation wells. In fact, there are many types of wells, and they are used not only for extraction, but also to study the geological structure of the subsoil, prospect for new deposits, support mining, etc. The oil and gas extraction industry can be classified into four major processes.• Exploration,• Well development,• Production,• Site abandonment. Exploration involves the search for rock formations associated with oil or natural gas deposits, and involves geophysical prospecting and/or exploratory drilling. Well development takes place after exploration has located an economically recoverable field and involves constructing one or more wells from inception (called spudding) until abandonment if no hydrocarbon is found or until upon completion of the well if hydrocarbons are found in sufficient quantities. Production is the process of extracting hydrocarbons and separating them. the mixing of liquid hydrocarbons, gases, water and solids, removing non-saleable constituents and selling the liquid hydrocarbons and gas. Production sites often process crude oil from multiple wells. Oil is almost always processed in a refinery; Natural gas can be treated to remove impurities either in the field or at a natural gas processing plant. Finally, site abandonment involves plugging the well(s) and remediating the site when a recently drilled well does not have the potential to produce economic quantities of oil. or gas, or when a producing well is no longer economically viable.Traditio...... middle of paper...... technological advances mean that a well today can produce two times more than a single well in 1985. • Drilling waste decreased to 148 million barrels due to increased well productivity and fewer wells. • The drilling footprint of well platforms has decreased by up to 70 percent thanks to advanced drilling technology, extremely useful for drilling in sensitive areas. areas.• By using modular drilling rigs and slim boreholes, the size and weight of drilling rigs can be reduced by up to 75 percent compared to traditional drilling rigs, thereby reducing their impact on the surface. • Technology, and therefore drilling footprints, had remained at 1985 levels, current drilling footprints would occupy an additional 17,000 acres of land. • New exploration techniques and vibration sources mean less reliance on explosives, reducing the impact of exploration on the environment..