5. Fault drilling
You’ve undoubtedly heard of the San Andreas Fault in California. A fault line like that is the edge of two enormous rock blocks (or “plates”) in the Earth’s crust that rub against each other (or “slip”) during an earthquake. San Andreas is massive. It’s roughly 800 miles long and forms the tectonic boundary between the Pacific Plate and the North American Plate. Most fault lines aren’t that huge. When drilling oil wells, we frequently run into smaller fault planes. It can be difficult and risky to drill a vertical well through a steeply inclined fault plane. Many times, the drillbit or downhole motor assembly will “walk” or “move” along the fault plane. This will take the wellbore away from the target formation. So the wellbore may be directionally drilled perpendicular or parallel to the fault for better production.
6. Salt-dome exploration
A salt dome forms when salt is concentrated by evaporation and slowly drifts upward. Over time, it is surrounded by sediments (rocks).
93
Made with FlippingBook - Online Brochure Maker