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Frac@Shoe/GG Above

In this section we describe the load case "Frac@Shoe/GG Above", available in Oliasoft WellDesign™.​


Frac@Shoe/GG Above is a burst load case, where the unknown is the internal pressure profile of the tubing.

NOTE!
In this documentation we denote any tubular as casing or tubing. All calculations however encompass any tubular, such as tubings, casings, liners, tie-backs etc.


Summary​

This load case reflects that the formation fractures just below the casing shoe and where the entire casing is filled with gas. The pressure at casing shoe equals fracture pressure and the pressure from casing shoe to hanger is given by subtracting the hydrostatic gas column.

Overriding Wellhead pressure will shift the pressure graph. If you increase the pressure from the inital wellhead pressure in the load case, you will also exceed the fracture pressure at the shoe.

Illustrating Pressure Profile Graph​


Inputs​

  1. The true vertical depth (TVD) along the wellbore as a function of measured depth. Alternatively, the wellbore described by a set of survey stations, with complete information about measured depth, inclination, and azimuth.
  2. The true vertical depth (TVD) of
    1. The hanger of the tubing, TVDhanger_{hanger}
    2. The shoe of the tubing, TVDshoe_{shoe}
  3. The fracture pressure profile at shoe.
  4. The Gas Gravity/Gas Density​
  5. A fracture margin of error, added to the fracture pressure.