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Injection Down Casing

In this document we describe the load case "Injection down casing"#


Injection down casing is a burst load case, where the unknown is the internal pressure profile of the casing / 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 is a load case that models an applied surface pressure to a static fluid column.


Printable Version#


Oliasoft Technical Documentation - Injection Down Casing


Inputs#


The following inputs define the injection down casing 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, inclination, and azimuth.
  2. The true vertical depth / TVD of
    1. The hanger of the casing/tubing, TVDhangerTVD_{hanger}
    2. The shoe of the tubing, TVDshoeTVD_{shoe}
  3. The applied injection pressure, pinjp_{inj}
  4. The density of the injection fluid, ฯinj\rho_{inj}

Calculation#


The internal pressure profile of the tubing is simply calculated as

pi=pinj+ฯinjโ€‰gโ€‰h,TVDhangerโ‰คhโ‰คTVDshoep_i = p_\text{inj} + \rho_\text{inj}\, g\, h, \qquad\quad \text{TVD}_{\text{hanger}} \leq h \leq \text{TVD}_{\text{shoe}}