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P&A PressureTest

In this section we describe the load case "P&A PressureTest" available in Oliasoft WellDesign™.​


P&A PressureTest 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​

The P&A (Plug and Abandonment) pressure test is a burst load case. The internal pressure distribution is determined based on the "Pressure Above estimated Leak-Off Test (LOT) at the casing shoe," with the LOT value set to match the fracture pressure. The pressure profile from the casing shoe to the hanger and is calculated by subtracting the hydrostatic pressure from the mud. //: # (end - summary)


Illustrating Pressure Profile Graph​

Printable Version​

Oliasoft Technical Documentation - P&A Pressure Test


Inputs​

The following inputs define the Pressure Test 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, ρmud\rho_{mud}.
  5. The test pressure above estimated LOT, PAboveLOTP_{Above LOT}
  6. Pfrac@shoeP_{frac@shoe} //: # (end - inputs)

Calculation​

The internal pressure profile is given by "The Pressure Above estimated LOT at shoe", and the hydrostatic mud column from casing shoe to hanger. "

Pi=Pfrac@shoe+PAboveLOT−gρmudTVD,TVD  ϵ  [TVDshoe,  TVDhanger].                                         (2)P_{i} = P_{frac@shoe} + P_{Above LOT} - g\rho_{mud}TVD, \qquad \qquad \qquad \qquad TVD \; \epsilon \; [TVD_{shoe}, \; TVD_{hanger}]. \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (2)