全球钻井和完井液市场报告(2016-2020年)
In the past century, fossil fuels were the chief source of energy worldwide. Among fossil fuels, crude oil has controlled almost all the aspects of the energy business. Crude oil is defined as a mixture of compounds composed primarily of carbon and hydrogen in varying proportions. It also has inorganic compounds such as nitrogen and sulfur and metals like vanadium and mercury. Crude oil is found in specific rock formations, called reservoirs, in the earth's crust. The depth at which petroleum reservoirs are found can vary from oil seeps that flow up to the surface to almost 15,000-meter underground. To reach these reservoirs of crude oil, the surface needs to be drilled until the pre-defined depth is reached.