Conductor Casing - Available in sizes between 18" to 36", conductor casing is the first interface between surface and subsurface. It serves many purposes, such as prevent well collapse, protection against shallow gas pockets, fluid circulation and general support for drilling a well. Conductor could be installed either by drilling or using a hammer to hammer the conductor to the soil.
Surface Casing - Although varying in sizes depending on application, the common size of surface casing is 13⅜”. Surface casing is used mainly for environmental and safety reasons, such as isolating freshwater zones, blowout protection, supporting a wellhead and blow out prevention (BOP) equipment. It is also required to case off unconsolidated formations and serves as a support for next casing strings. Surface casing is always subject to extremely high safety standards and regulations.
Intermediate Casing (not always required) - Available in sizes between 13 3/8” and 16”, Intermediate casing is placed between surface and the production casing / liner. In general, intermediate casing is run in deeper wells to provide isolation of abnormally pressured formations, potential lost circulation area and unstable shale sections. These risk mitigation factors, also allow drilling the well to a planned depth with required mud weights.
Production Casing - Normally coming in sizes between 4" and 9 5/8”, production casing is required to provide a structural integrity and pressure control of the hydrocarbon bearing sections, during production. Perfect cementing job is critical when setting the production casing.
Production Liner - is suspended inside of the production casing (or any other previous section) using a liner hanger system. Major benefit using the liner is cost saving, as it is not run to the full depth of the well. Liners could be pre-perforated so save time and money and mainly used in slim holes or sidetracking inside the reservoir section.Contact us Skype:Kaden Shi