Circulating is the pumping of drilling fluid from the suction pit, through the drill pipe and back to the surface through the annulus. Although mud is circulated, the terms “circulated” or “circulating” applies to this operation while drilling is temporarily suspended, to obtain samples from bottom or keep hole in condition while awaiting other operations.
Cementing is the operation by which a cement slurry is forced down through the casing and out at the lower end in such a way that it fills the space between the casing and the sides of the well bore to a predetermined height above the bottom of the well. This is for the purpose of securing the casing in place and excluding water and other fluids from the well bore. All cements are in a liquid phase and able to be pumped by pumps.
Fracturing is a means of opening the fissures in the Barnett Shale formation by the use of hydraulic pumps and fracturing fluid. Fresh water stored in frac pits is pumped in stages into the Barnett Shale formation. Once fractures in the rock have been created, sand (like beach sand) is mixed with the fresh water and pumped into these fractures to help prevent the fracture from closing back once the hydraulic force is reduced. By packing or filling of these fractures with sand, this will allow the formation to produce into the new drilled well bore (hole) and bring gas to surface.
A term applied to the valves and fittings assembled at the top of a well to control the flow of the gas. These valves and fittings are all pressure tested to a minimum of 5,000 psi before and after installing.
A tank battery is a group of tanks that are connected to receive produced water from a well. A tank is normally a single- or double-steel or fiberglass vessel that can hold 200-400 barrels. The tank battery also includes some production equipment, such as gas separators which allow the produced water to be separated from the gas. The produced water is removed from the tanks by truck, and taken to disposal facilities outside of the City.
A device attached immediately above the casing to control the pressure and prevent the escape of fluids from the annular space between the drill pipe and casing or shut off the hole, if no drill pipe is in the hole, should a blowout occur. These devices are pressure tested between 3,500 – 5,000 psi when installed and every two weeks afterwards.