Oil applications, in general, work on the discovered large reservoirs, highlighting such structures in the soil and turning them into benefits over time. While doing all these, exploration, machine-supply, drilling, well completion and production units are activated, respectively, and the stages from seismic exploration to production are completed. Oil exploration often relies on geophysical technologies to detect underground and determine the extent of possible structures. Oil and gas exploration is a very expensive activity and has a high risk of failure. If it is found in small quantities, it is useless to produce. For example, only about one-eighth of the oil and gas exploration wells in the North Sea can reach commercially profitable oil and gas quantities. Drilling of the first well is usually started a few years after the granting of the exploration license.
The exploration evaluation phase includes drilling more wells to reduce the degree of uncertainty about the size and quality of the potential field. If an exploratory well confirms good hydrocarbon capacity, additional seismic data can be collected and one or more detection wells can be drilled. With the data obtained by these methods, it is possible to estimate the oil and gas amounts and the ease/difficulties of production in that region.
The last stage is the Production stage. It includes, in varying proportions, oil and gas production. Factors that create value at this stage are production well planning, maintaining production speed and maximizing production life by injecting gas or water into specially designed injector wells to maintain well pressure.