Building the Wells

After geologists and reservoir engineers determine where the wells
should be, crews level the site, construct a lease road, erect the
drilling rig, and place support facilities on the pad. for efficiency,
and to minimize disturbance at the surface, BhP Billiton Petroleum
typically drills and completes several wells from a single pad,
directing each wellbore to a different part of the target zone. When the wells are to be hydraulically fractured, an array of large trucks,
pumps, storage units, and control systems will be brought in for
several days. once all the wells are completed, the perimeter of the site is restored as close as possible to its original condition, leaving only a minimal surface footprint.

Surface drilling and casing
Drillers start a new well by drilling a hole to a depth of
approximately 80-100 feet, and installing a large-diameter pipe called a conductor casing, which is then cemented in place.

Protecting the water table
once the conductor casing is set, drilling continues to a depth that
state regulatory agencies determine is well below the level of any fresh ground water. the heavy pipe called surface casing is then
installed and cemented in place by pumping cement down the pipe. the cement circulates to the bottom of the surface casing and rises
back to the surface on the outside of the casing, forming another layer of protection and strength.

Horizontal drilling
Shale wells are usually completed with a horizontal section. As the
wellbore continues downward and it approaches the target shale, drilling engineers guide the drill bit, curving the borehole until its
path is horizontal or nearly so. the finished hole may run horizontally for a mile or more through the hydrocarbon-rich layers of rock.

Production Casing
the drilling phase is finished after drillers install and cement an
additional set of piping from the bottom of the well all the way back to the surface, forming yet another barrier between the rock and the inside of the well.