Changes

The slotted liner completion is similar to an open hole completion and has all the major advantages and disadvantages discussed for open hole completions. The only difference is that a slotted liner is hung in the open hole interval to minimize [[/Drilling_problems#Hole_instability|sloughing]] of the formation into the well bore ([[:Image:Charles-l-vavra-john-g-kaldi-robert-m-sneider_capillary-pressure_1.jpg|Figure 1b]]). A screen and liner completion is similar to the slotted liner completion in that a screen and liner is set in the open hole section of the wellbore. The difference is that gravel is sometimes placed behind the screen ([[:File:Well-completions_fig2.png|Figure 2a]]). The advantages and disadvantages are the same as for open hole completions. The screen and liner completion is used primarily in [[unconsolidated]] formations to prevent the movement of formation materials into the wellbore, restricting the flow of reservoir fluids.

The slotted liner completion is similar to an open hole completion and has all the major advantages and disadvantages discussed for open hole completions. The only difference is that a slotted liner is hung in the open hole interval to minimize [[/Drilling_problems#Hole_instability|sloughing]] of the formation into the well bore ([[:Image:Charles-l-vavra-john-g-kaldi-robert-m-sneider_capillary-pressure_1.jpg|Figure 1b]]). A screen and liner completion is similar to the slotted liner completion in that a screen and liner is set in the open hole section of the wellbore. The difference is that gravel is sometimes placed behind the screen ([[:File:Well-completions_fig2.png|Figure 2a]]). The advantages and disadvantages are the same as for open hole completions. The screen and liner completion is used primarily in [[unconsolidated]] formations to prevent the movement of formation materials into the wellbore, restricting the flow of reservoir fluids.

The cemented liner completion is used when [[intermediate casing]] is set in a well prior to reaching total depth ([[:File:Well-completions_fig2.png|Figure 2b]]). Many times intermediate casing is used to isolate zones behind pipe such as low pressured intervals that tend to cause [[Drilling_problems#Lost_circulation|lost circulation]] problems or to isolate zones such as sloughing shales or salt layers. Intermediate casing is also set in transition zones between normally pressured intervals and geopressured intervals. After the casing is set, the weight or chemistry of the drilling fluid can be changed to continue drilling the well. The cemented liner completion is advantageous because the particular intervals behind the liner can be selectively perforated. This selection will allow one to control both the production and injection of fluids in those intervals. he main disadvantage of a cemented liner is the difficulty encountered in obtaining a good primary cement job across the liner. If a good cement job is obtained, then a cemented liner completion is very similar to a perforated casing completion.

The cemented liner completion is used when [[intermediate casing]] is set in a well prior to reaching total depth ([[:File:Well-completions_fig2.png|Figure 2b]]). Many times intermediate casing is used to isolate zones behind pipe such as low pressured intervals that tend to cause [[Drilling_problems#Lost_circulation|lost circulation]] problems or to isolate zones such as sloughing shales or salt layers. Intermediate casing is also set in transition zones between normally pressured intervals and [http://www.glossary.oilfield.slb.com/en/Terms/g/geopressure.aspx geopressured] intervals. After the casing is set, the weight or chemistry of the drilling fluid can be changed to continue drilling the well. The cemented liner completion is advantageous because the particular intervals behind the liner can be selectively perforated. This selection will allow one to control both the production and injection of fluids in those intervals. he main disadvantage of a cemented liner is the difficulty encountered in obtaining a good primary cement job across the liner. If a good cement job is obtained, then a cemented liner completion is very similar to a perforated casing completion.

==Perforated casing completions==

==Perforated casing completions==