Casing Design for High Pressure/High Temperature Wells

Abstract

A satisfactorily and economically viable Surface and Intermediate Casing are designed for a high pressure, high temperature (HPHT) well (Nini-55) in the Niger Delta Basin. Based on the estimated parameters (Pore Pressure, Fracture Gradient, and Pressure Gradient) the Burst, Collapse and Tension loads were calculated employing their various design and safety factors. Based on the design calculations, the relevant physical properties (weight, grade, connector, and diameter) were selected from tables or Casing Catalogues. These properties were matched onto each design and the best combination strings were used. The numerical values of these design loads were plotted on a graph and interpreted. Also, treated in this work are the possible remedies for high pressure, high temperature wells.

Keywords: surface casing, intermediate casing, burst pressure, collapse pressure, axial tension