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Perforation Gun Pressure

In this section we describe the load case "Perforation Gun Pressure" available in Oliasoft WellDesign™.​


Perforation Gun Pressure is a burst load case, where the unknown is the internal pressure profile of the tubing. //: # (end - introduction)

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


Summary​

Perforation Gun Pressure is a burst load case for production. The internal pressure is determined by the trigger pressure applied during perforation, causing a sudden spike in pressure. This pressure increase is combined with the hydrostatic pressure generated by the fluid within the casing. The overall pressure, from the hanger to the casing shoe, is the sum of the trigger pressure and the hydrostatic column pressure created by the mud, extending from the wellhead (RKB) down to the casing shoe. //: # (end - summary)


Illustrating Pressure Profile Graph​


Inputs​

The following inputs define the Perforation Gun Pressure load case

  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 and inclination.
  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 temperature profile of the wellbore, TT.
  4. The mud weight/density, ρinternalfluid\rho_{internal fluid}.
  5. The Perforation Trigger pressure, PtriggerP_{trigger} //: # (end - inputs)

Calculation​

The internal pressure profile is given by the hydrostatic pressure from the internal fluid plus trigger pressure from hanger the the casing shoe.


Pi=Ptrigger+gρintenralfluidTVD,TVD  ϵ  [TVDhanger,  TVDshoe].                                         (1)P_{i} = P_{trigger} + g\rho_{intenral fluid}TVD, \qquad \qquad \qquad \qquad TVD \; \epsilon \; [TVD_{hanger}, \; TVD_{shoe}]. \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (1)