TERMINOLOGY
As with most industries, Oil Development and Production uses a host of specialized terms. A short alphabetical list of commonly used language in our industry is included here with definitions.
Commercial Well: A well capable of producing oil or gas in quantities sufficient to cover all expenses of operation.
Completion Process: The final steps in the effort to produce from the well. The initial step is to run and cement casing. The casing is then perforated opposite the producing zone. Well completions vary according to the kind of well, depth, and the formation from which it is to produce. The zone is then swabbed. Thereafter, the well is shut-in for a period of days to allow pressure build up to attempt to gain a stabilized pressure. Control and flow valves are then installed atthe wellhead.
Conventional (or Diamond) Coring: A process where a special bit is attached to the drill pipe and run to the bottom of the hole. As the bit tool is rotated, it cuts a cylindrical core, which is received in a tube above the core-cutting bit. The tool is then removed, and a sample of the formation rock is retrieved for examination and testing to determinethe qualities of the formation.
Developmental Well: A well drilled within the productive area of an oil or gas reservoir based on interpretation of available data.
Drill Stem Test: A method of determining the nature of the fluid in a formation and the formation pressure. When the depth to be tested has been reached in a well being drilled, a special tool is lowered into the hole and special devices are used to isolate the formation to be tested from the remainder of the well bore. The drilling mud is removed from this vicinity and the contents of the formation are allowed to flow into the tool, while an instrument measures the pressure. The tool is then removed from the hole and the contents examined.
Electric Well Log: An electrical survey conducted in the open well bore to determine and record certain electrical characteristics of the formations for the purpose of identifying them and making determinations regarding the nature of the formation and identifying fluids contained in the formation, and their depth.
Initial Potential: The initial potential production of an oil or gas well after testing operations and recovery. It should approximate closely the maximum ability of a well to produce on completion without subsequent reservoir damage.
Sidewall Coring: A process where a tool is lowered into the newly drilled hole and cookiecutter shaped cylinders are fired into the rock face to extract sample of the reservoir rock. Each sample is about the size and shape of a thumb. As with conventional coring, the samples are sent to a laboratory for analysis.
Swabbing: The process of fitting a device into the inside of the tubing to lift fluid from the inside of the tubing.
Total Depth (T.D.): The total depth to which a well is drilled.
Workover: A workover is an infield mechanical procedure whereby a light duty service rig is used to seal off a depleted oil zone and then open up another zone above the depleted zone to allow oil to be produced from the new zone. In salt dome fields, multiple pay zones for one well are common.