Patent ID: 8088717
Filing Date: 2012-01-03
Classification: B29C,C09K,Y10T

Abstract:
1. A method associated with drilling a well comprising: selecting reusable compressible objects, wherein each of the compressible objects has a shell having an aspect ratio between 3 and 4 when the pressure external to the shell is equal to the pressure internal to the shell, the shell enclosing an interior region having an internal pressure of at least 500 psi at atmospheric external pressure, the internal pressure expanding the volume of the compressible object from an initial state to an expanded state having maximum strain that does not exceed the maximum elastic strain of the compressible object, the interior at least partially filled with a foam, wherein the shell is designed to compensate for localized elastic strains on the compressible object during expansion and compression of the compressible object and wherein the shell is configured to experience less strain when the external pressure is about equal to the internal pressure than when the external pressure is greater than the internal pressure or less than the internal pressure; selecting a drilling fluid; introducing the compressible objects to the drilling fluid to form a variable density drilling mud, wherein the variable density drilling mud provides a density between a pore pressure gradient and a fracture pressure gradient for at least one interval of a well as the variable density drilling mud circulates toward the surface of the well; and drilling a wellbore with the variable density drilling mud at the location of the well.