A petroleum engineer is employed by a petroleum company to design, test, and implement methods to extract gasoline and oil from the earth and sea floor. Petroleum engineers are involved in locating the dig site, building the machines that perform the extraction, and overseeing the removal and processing of the petroleum itself. Engineers work closely with geologists and other petroleum company team members to safely execute oil and gasoline extraction and refinement.

The development of tools, machines, and equipment used to extract oil and gasoline is part of a petroleum engineer's job description. Operating software used to control and run the machines is also frequently written with contributions by a petroleum engineer. On site, machines used to remove oil and gasoline are often operated by engineers themselves. Experienced engineers may oversee individuals and teams employed on a job site, and manage a job site's overall production.

Petroleum engineers develop methods to safely and efficiently extract as much oil and as gas possible while working to keep costs low. This typically includes a financial analysis to make sure the operation is profitable to incur the expenses of removing the crude materials, relative to the money earned from selling the refined gasoline and oil. A petroleum engineer uses methods of data organization and analysis to accomplish this task, and may present research and report findings to company management to aid with the decision making process.

Field work and extensive travel are both usually necessary for a petroleum engineer, as much of the job may need to be completed on-site at remote oil and gas repositories that are located in many different regions and countries. Job requirements will vary depending on the company and individual position, and some work may be completed in an office or laboratory environment. Petroleum engineers also work in academia, teaching university classes and conducting research on new methods to locate and remove petroleum.

Education requirements to become a petroleum engineer include obtaining an undergraduate engineering degree from a college or university. Some positions and companies may require additional education in the form of a masters degree or doctorate in petroleum engineering. It is important for petroleum engineers to have a strong background in geology, physics, mathematics, and computer programming. Career progression for a petroleum engineer typically involves starting out working for a company building equipment and conducting field research, and then moving up to the location, operation, planning, and management of a oil and gasoline job site.