Casing Design

Casing Design 

The latest version of the program is the most flexible and user friendly program on the market, Developed for Microsoft Excel

 API rated burst strength is de-rated for temperatures from 10 to 600 F° (-12 to 316 C°) Drilling Condition – Gas/oil kick while drilling below the shoe with partial or total mud evacuation (user selects evac percent), with shut in pressurized column of gas/oil to surface and old mud weight gradient behind casing. The old MW that was behind the casing when it was cemented is used for annulus hydrostatic burst calculations and the present MW is used for internal hydrostatic calculations. The user inputs the gas/oil gradient that most closely fits their design for internal pressure gradient.

Production Condition – 100% mud evacuation with full column of shut in pressured gas/oil to surface and salt water gradient behind casing

Drilling burst loads are calculated assuming a shut in gas/oil kick with Leakoff EMW pressure at the shoe and a casing evacuation percent chosen by the user (typically 10 – 40 %).

Production burst loads are calculated assuming a full shut in column of pressured gas/oil (i.e. 100% mud evacuation), with Leakoff EMW pressure at the shoe and a column of salt water behind the casing. .

Collapse Design API rated collapse strength is de-rated for temperatures from 10 to 600 F° (-12 to 316 C°). . The temperature de-rated collapse can also be further de-rated for axial tension if desired.

Drilling collapse loads are calculated assuming the casing has been partially or fully evacuated of mud (resulting from lost circulation, or a blowout), while drilling below the shoe, with a non-pressured column of gas/oil to the surface (i.e. atmospheric pressure at the surface) and a full column of old MW behind the casing. The user inputs the gas/oil gradient that most closely fits their design for internal pressure gradient.
. Production collapse loads are calculated assuming 100% mud evacuation with an un-pressured column of gas/oil to the surface. The old MW that was behind the casing when it was cemented is used for annulus hydrostatic collapse calculations. The user inputs the gas/oil gradient that most closely fits their design for internal pressure gradient.

Cementing Collapse loads are calculated with applicable hydrostatic columns of mud and cement slurries outside the casing and displacement fluid column inside the casing. The small hydrostatic difference of the cement in the shoe joints is ignored and displacement fluid is assumed to the shoe TVD. Cementing collapse is typically a concern with big OD conductors and surface casings.

Tensile Design API rated tensile strengths (body and joint), are de-rated for temps 10 to 600 F (-12 to 316 C). . Drilling and Production Casings are calculated with the same assumptions.

Tensile analysis considers the total hanging weight of the casing as it is being run in the hole. The user selects Vertical or Directional tensile analysis to calculate tensile loads assuming buoyant weight of steel in a mud filled hole. . Buoyancy factor = (65.4-MW)/65.4

Vertical tensile load assumes casing hanging in a vertical hole with drag forces ignored.

Directional tensile load assumes the true vertical (TVD) length, of the casing at any specified depth (i.e. axial tensile load), with drag forces ignored. . Directional program calculates TVD’s from user input survey data.

Casing Design includes a combination of csg and Liner installation

Linked to Well Trajectory and Azimuth Closure

The program covers both Vertical, Directional designs for On Shore, Shallow Water Offshore, Deep Water Off Shore . Feet or Meters, temperature de-rating factors, cementing safety factors Burst, Collapse, Tension Safety Factors can be API  or user defined.

4138 different joints of casing to choose from plus custom editable casing database this allows the input of  unlimited custom casing sizes to be added to the database.

Program details (steaming video)

How to import a saved survey

Summary

  • De-Rated Burst and Collapse due to temperature affect vs.  Burst and Collapse loads (psi) at the top and bottom of up to 4 different rated casing sections, or combination cemented in place casing plus up to 3 liners
  • For example:
  • in place casing plus Liner1 with three different sections (spec)
  • In place casing plus Liner 1 two different sections (spec) plus Line2
  • In place casing Liner1, Liner 2, Liner3
  • In place casing Liner1, Liner2 plus two different sections (spec)
  • Completely adaptable to any combination of casing and liners
  • De-Rated Tensile Strength vs. Tensile Loads (lbs.) at the top and bottom of up to 4 different rated casing sections
  • Yield Strength De-Rating Factors vs. Temperature in °F & °C
  • Vertical Section View chart
  • Plan View chart
  • Dog Leg Severity (100’ or 30 Mtrs) chart
  • Export and Email reports

The program covers  On Shore, Shallow Water Offshore and Deep Water Offshore calculations

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