Preparing a well for production is a complex process. Press the Play button to see each step in the process.
Step 1 - A pipe, called the casing, is lowered down the drilled hole. Sections of casing fit together just like the drill pipe. Cement is then pumped through the bottom of the casing so that it fills the area between the casing and side of the well. The casing prevents oil, gas and deep brines (underground salt water) from entering and contaminating aquifers (underground fresh water).
Step 2 - Because the casing and the liner must remain in a well for a long time and their repair or replacement would be costly, another string of pipe is placed in the well through which oil or gas is usually produced. This string of pipe is called "tubing". This is like a double-hulled tanker in that it provides an extra layer of protection for groundwater supplies. Tubing is pulled out of the hole on occasion and inspected to see if it needs to be repaired. (Casing is cemented in and can be repaired, but not as easily as the tubing).
Step 3 - Operators do not want anything but oil and natural gas to enter the well. To allow underground fluids to enter the pipe and flow to the surface, the tubing and casing must be perforated. Explosive charges are lowered to the precise depth of the oil reservoir. Detonating the charges forces holes in the casing. Fluids can then flow into the casing and up the tubing toward the surface.
Step 4 - A "Christmas Tree" is a device that is placed on the well at the surface. It regulates the flow from the well into the pipelines that take the oil and natural gas to facilities for processing and sale. It consists of a series of valves that are opened and closed to regulate flow for optimum field production or to shut down a producing well if a problem is detected. Some Christmas Trees have computer systems that allow them to be monitored, opened and closed remotely.»next