Well completion incorporates the steps taken to transform a drilled well into a producing one. These steps include casing, cementing, perforating and installing a production tree.
The first step in completing a well is to case the hole. After a well has been drilled, should the drilling fluids be removed, the well would eventually close in upon itself. Casing ensures that this will not happen while also protecting the wellstream from outside objects such as sand or water.
The next step in well completion involves cementing the well. This includes pumping cement slurry into the well to displace the existing drilling fluids and fill in the space between the casing and the actual sides of the drilled well. Consisting of a special mixture of additives and cement, the slurry is left to harden, sealing the well from non-hydrocarbons that might try to enter the wellstream, as well as permanently positioning the casing into place.
3. Open-Hole Completions
At the reservoir level, there are two types of completion methods used on wells: open-hole or cased-hole completions. An open-hole completion refers to a well that is drilled to the top of the hydrocarbon reservoir. The well is then cased at this level, and left open at the bottom. Also known as top sets and barefoot completions, open-hole completions are used to reduce the cost of casing where the reservoir is solid and well-known.
Cased-hole completions require casing to be run into the reservoir. In order to achieve production, the casing and cement are perforated to allow the hydrocarbons to enter the wellstream.This process involves running a perforation gun and a reservoir locating device into the wellbore, many times via a wire line, slickline or coiled tubing. Once the reservoir level has been reached, the gun then shoots holes in the sides of the well to allow the hydrocarbons to enter the wellstream. The perforations can either be accomplished by firing bullets into the sides of the casing or by discharging jets, or shaped charges, into the casing.
Canadrill has extensive experience in multi-fracing Cardium & Montney wells in Western Canada.
6. Production Tree
The last step in completing a well, a wellhead is installed at the surface of the well. Many times called a production tree or Christmas tree, the wellhead device includes casingheads and a tubing head combined to provide surface control of the subsurface conditions of the well.