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Production EngineeringWell Performance

Entrance Hole Size from Casing Yield Strength Formula

d=(σyrσy)0.5drd=\left(\frac{\sigma_{yr}}{\sigma_y}\right)^{0.5}d_r

Entrance Hole Size from Casing Yield Strength calculates entrance hole diameter in casing of interest for well performance workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (sigma_yr, sigma_y, d_r) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.

Assumptions

  • Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
  • The declared units match the field-unit constants used in the formula.
  • The cited formula applies to the selected petroleum engineering workflow.

Limitations

  • The calculation does not replace a full engineering model or operating procedure.
  • Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

  • Mixing unit systems without converting the inputs.
  • Using default example values as field recommendations.
  • Applying the formula outside the source assumptions.

Default example

Using the default inputs, d equals 0.358177 in.

sigma_yrksi

80

sigma_yksi

110

d_rin

0.42

Inputs

sigma_yr

ksi

Yield Strength of Reference Casing

sigma_y

ksi

Yield Strength of Casing of Interest

d_r

in

Entrance Hole Diameter in Reference Casing

Outputs

d

in

Entrance Hole Diameter in Casing of Interest

d_r

in

Entrance Hole Diameter in Reference Casing

sigma_y

ksi

Yield Strength of Casing of Interest

Source and review

reviewed

Bell, W.T., Sukup, R.A. and Tariq, S.M. 1995. Perforating, Henry L. Doherty Memorial Fund of AIME, Society of Petroleum Engineers, Page 50.

Source

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