Drilling one well can take almost a month by the time the location is built, everything moved in and set up, hole drilled and cased.
Next the drilling rig is moved off and a work over rig is moved in. It can take a week or more depending on what is needed. If they need to frack then times depend on the frac crew.
After the work over rig is moved off the roustabout crews come in and setup the pumping unit, trench and lay lines to the treater and storage tanks, lines need to be trenches and laid to the nearest pipeline, or they can do without that and truck the oil from the storage tanks.
All that can be as long as two or three months sometimes longer. Now consider that even a small field can have twenty or thirty wells.large fields can have four, five hundred or more wells.
Part of the problem with just not punching hole after hole is do we have the refining capacity? Enviromental requlations. Pipeline capacities.
If we have to build other refineries or enlarge existing ones that can take years. If you have to have a loading facility that can also take years. Building a pipeline above ground is actually more costly then below ground because of requlations.
Hope this answers your questions.