Abstract:
In the oil & gas industry BOP`s or Blow Out Preventers are the devices that are used to
seal the well bore in an emergency situation and prevent the well bore fluids to reach the
surface and cause damage. BOP`s consists of several stacks of preventers mounted on one
over the other, the final defense is the shear ram, that shears the drill pipe or any tubular
present in the well bore by passing through it completely. The manufacturers of the
BOP`s use the basic equation of the “The Distortion Energy Theory” for the estimation of
the shear forces of the tubular required for the shearing operation in case of activation of
shear rams of the BOP`s . With the development of new technology and advancement of
drill pipes materials, the basic equation i.e. the distortion energy theory (by using yield
strength or tensile strength) would not be good enough to give an estimate of the shearing
force .Failure of activation of shear rams would result in blowout accident, resulting in a
great loss of life and property. In the current research, analysis and simulations are being
done using FEM software DEFORM-3D .The analysis is carried out on the drill pipes,
shear rams and varying pipe dimensions and applying different conditions to perform the
simulations of the shearing operation when the shear rams would be operated. The results
are compared with the theoretical calculations, experimental results and the shearing
tubular data provided by the manufacturers of the BOP`s to know how accurately the
DEFORM-3D results can provide the estimation of the shear forces of the drill pipes and
additionally the tool joints also .Further analysis is done by considering actual well
conditions applied to drill pipes, shear blade geometry effect , temperature ,kick
conditions ,tool clearance and non-centralized string effects on the shearing force of the
drill pipes.
