You may not need to pursue a post-secondary education in order to become a well digger, but in certain circumstances, you should be prepared to undergo plenty of on-the-job training to learn the skills and techniques necessary to drill wells safely and effectively. It is likely that you will need to graduate from high school or earn an equivalent qualification, though this is not always the case. You can, for example, become a well digger by undergoing job training or an apprenticeship instead, but you will likely need to demonstrate basic math and communications skills.
Most regions of the world have certain licenses or certifications that you must obtain in order to become a well digger, and it is best to research the various qualifications that are necessary before you pursue a path that will allow you to enter this job field. Fees are generally associated with licensing, and you will probably need to prepare for these exams on your own or take a prep class in order to pass. You can get hired by a drilling company in an entry-level capacity and learn basic skills on the job in preparation for your licensing as well, though you will not be able to become a well digger right away.
On oil rigs, well diggers are usually highly trained. It may be necessary to earn a college degree in order to become a well digger in this capacity; many diggers have backgrounds in geology or related fields, though it is still possible to become a digger without a degree. Post-secondary training will probably be necessary, however, and you will likely undergo a lengthy apprenticeship. During your apprenticeship, you will work under the guidance and supervision of a more experienced well digger or a supervisor so you can learn the skills necessary to dig wells effectively. This apprenticeship can vary in duration, but you should expect to spend anywhere from one to four years as an apprentice.
Once you complete the apprenticeship, you will probably need to pass some licensing exams before you can work independently. You will become a well digger once you are properly licensed and the apprenticeship is complete; as a digger, you will probably work on a team with several other well diggers, and you should be prepared to spend a good portion of your work day on your feet performing various physical tasks.