The oil and gas sector requires high amounts of investments, technology, and qualified human resources. Proper management of the oil and gas sector will require deep knowledge of the sector, including oil and gas formation, upstream activities (exploration and production), downstream activities (processing, transport, and distribution), and dynamics of the oil and gas sector.
The search for oil and gas begins with a geological and geophysical survey, including seismic and gravitational survey to search for oil traps. Wild cat drilling is then carried out in order to find oil reserves in these traps. If this drilling is successful, it will provide data on the amount of hydrocarbon, rock formations, and the amount of oil and gas available. These data are then used to make a rough estimate of oil and gas so that production may begin immediately.
Oil and gas production is carried out by drilling production wells in developed fields. In a certain amount of time (ex: 25 years of contract), a production well may only produce a certain amount of oil and gas, limited by their reserves. Several production wells are required in order to achieve production target during the contract period.
There are two types of costs associated with this process; well and non-well cost, which includes production equipments, supporting infrastructures, oil and gas transport, and maintenance costs for field development.
Oil and gas production process is divided into three different process, primary recovery, secondary recovery, and tertiary recovery. Primary recovery is a production process which exploits the natural gas pressure available by using pumps or gas lift.
Secondary recovery is done by water or gas flooding process, meanwhile tertiary recovery is carried out by adding polymer towards the injected water / gas to decrease the viscosity of oil, in-situ combustion, or microbial injection. Second and tertiary recovery is also known as Enhanced Oil Recovery.
Oil and gas wells will require maintenance or stimulation in order to maintain production levels. This activity is known as work over - aimed at shifting production to other layers, scaling – clearing the well of deposits, acidizing, and fracturing – opening of cracks in order to increase fluid flow.
source : http://www.esdm.go.id/index-en/54-articles/3103-activities-of-upstream-oil-and-gas-sector.html
