After the casing string has been designed to withstand the anticipated collapse and burst loads, it should be checked against the loads that will be experienced during the installation, and against the loads experienced during cementation and pressure testing. Such loads are calculated on the basis that the string is fixed (suspended) at surface but … Installation loads

The buckling theory showed that for buckling to occur, the reduced axial force, Fa*, must be negative. However, it is not necessarily the case that buckling will occur if the reduced axial force is less than zero. The capacity of the pipe to resist buckling will depend upon its dimensions, material properties, the well profile … Resistance to buckling

This article describes the methods to quantify the different casing loads are presented. Internal and external pressure profiles are generally independent and therefore separate design loads will be generated. The comparison of the internal and external pressure loads results in either a collapse load line or in a burst load line. Collapse load The collapse … Pressure (Collapse and Burst) loads on casing

Introduction to Casing Design Loads (Collapse, Burst and tension Load) 1  Collapse Load The design load case for collapse is based on a partial evacuation of the casing string. For partial evacuation during the drilling phase, the internal pressure profile is based on mud losses to pore pressure. Full evacuation after a blow-out is evaluated … Casing Design Loads

1 Evacuation during drilling Collapse loads occurring during drilling are usually the result of borehole evacuation due to natural or induced losses. There are however other cases to be considered. 1.1. Internal pressure profile In a losses situation, the mud column will drop until the pore pressure at section TD is just balanced by the … Collapse loads

The load determination for a stove pipe, foundation pile or marine conductor is a complex issue. This determination is usually followed by specialised stress analysis resulting in the involvement of a Structural Engineering department. The load determination and related stress analysis for a conductor casing is less complex, but still requires a good knowledge of … Stove pipe, foundation pile, marine conductor and conductor string

1 Evacuation during drilling Collapse loads occurring during drilling are usually the result of borehole evacuation due to natural or induced losses. There are however other cases to be considered. 1.1. Internal pressure profile In a losses situation, the mud column will drop until the pore pressure at section TD is just balanced by the … Collapse loads

The load determination for a stove pipe, foundation pile or marine conductor is a complex issue. This determination is usually followed by specialised stress analysis resulting in the involvement of a Structural Engineering department. The load determination and related stress analysis for a conductor casing is less complex, but still requires a good knowledge of … Stove pipe, foundation pile, marine conductor and conductor string

It should be noted that the strengths require down rating to account for the effects of wear, corrosion and fatigue and for the effect of temperature on yield strength. The appearance of commercial casing analysis software has made triaxial stress analysis possible. The allowable value of the Von Mises equivalent stress is usually the yield … Load bearing capacity

By examining the reduced axial force, Fa*, in a casing string, the operating conditions under which the uncemented portion of the casing will buckle are defined. This leads directly to methods of preventing buckling. The axial force is influenced by changes in pressures and temperature that can occur once the string has been constrained by … Fundamental equation for reduced axial force