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Pressure Test

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


Pressure test 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​

Pressure test is a burst load case. The internal pressure profile is based on an applied test pressure at the wellhead, the hydrostatic pressure from mud, and the possibility to set a plug. If a plug is installed, the test pressure is only seen above the plug. The pressure below the plug is the hydrostatic pressure from the mud column. //: # (end - summary)


Illustrating Pressure Profile Graph​

Printable Version​

Oliasoft Technical Documentation - 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 plug, TVDplug_{plug}, if present.
  3. The temperature profile of the wellbore, TT.
  4. The mud weight/density, ρmud\rho_{mud}.
  5. The test pressure, PtestP_{test} //: # (end - inputs)

Calculation​

With plug \qquad The internal pressure profile is given by the hydrostatic pressure from mud plus test pressure from hanger to plug, and hydrostatic pressure from mud from plug to shoe, i.e.

Pi={Ptest+gρmudTVD,TVD  ϵ  [TVDhanger,  TVDplug],gρmudTVD,TVD  ϵ  [TVDplug,  TVDshoe],(1)P_{i} = \begin{cases} P_{test} + g \rho _{mud} TVD, \qquad &TVD \; \epsilon \; [TVD_{hanger}, \; TVD_{plug}], \\ g\rho_{mud}TVD, \qquad &TVD \; \epsilon \; [TVD_{plug}, \; TVD_{shoe}],\end{cases} \qquad \qquad \qquad \qquad \quad (1)


Without plug \qquad The internal pressure profile is given by the hydrostatic pressure from mud plus test pressure from hanger to shoe, i.e.

Pi=Ptest+gρmudTVD,TVD  ϵ  [TVDhanger,  TVDshoe].                                         (2)P_{i} = P_{test} + g\rho_{mud}TVD, \qquad \qquad \qquad \qquad TVD \; \epsilon \; [TVD_{hanger}, \; TVD_{shoe}]. \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ (2)