Wellbore Stability, Stabilization And Strengthening Available to Purchase

Technically challenging drilling environments are now encountered in many of the world's hydrocarbon plays. These are often manifested by narrow drilling windows that arise either from the geological setting or from depletion of the hydrocarbons within the field over an extended period. Narrow drilling windows require strict control of the equivalent circulating density (ECD) of the drilling fluid or the utilization of technologies that manipulate the near-wellbore environment so that drilling is allowed to progress using mud weights outside the prescribed mud weight window. There is a diverse range of such wellbore stabilization technologies, though most can be distilled into the concepts of wellbore isolation and wellbore strengthening. These are distinctively different from managed pressure drilling or underbalanced drilling technologies. The drilling window defines the range of hydraulic pressures required to maintain wellbore integrity while avoiding fracturing or collapse of the hole. Essentially the hydraulic pressure provides the balance between the physical rock properties and the earth's stress field. By manipulating one or several of these components, it is possible to change the state of equilibrium, thus preserving wellbore integrity while using sub-optimal mud weight. The authors review various wellbore stabilization technologies available in the industry, including physical, chemical, thermal, and mechanical methods