This data suggests that 1 mile is common for oil wells: https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.

This data suggests that 1 mile is common for oil wells: https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm Obviously, that’s not a meter wide hole, but it’s clearly possible.