Abstract: A method of managing lost returns in a wellbore is disclosed. The method includes contacting a filter cake with a treating fluid to remove metallic weighting agents from the filter cake, wherein the filter cake is disposed on a face of a formation fracture in the wellbore. The method also includes contacting the filter cake with a proppant slurry, wherein the proppant slurry contacts the filter cake concurrently with the treating fluid or after the treating fluid contacts the filter cake. This method may include increasing the filter cake permeability and may utilize a barite removal agent, such as a chelation agent. At least one related wellbore management method is disclosed, which provides for creating a fracture in the wellbore and propping open the fracture to increase wellbore integrity to utilize higher weight drilling fluids and prevent fractures from forming further down the wellbore.

Abstract: A process for drilling a well or a portion of a well capable of providing a generally constant interior wall diameter (monobore) and does not require installation of any liner or steel casing. The process comprises circulating settable material into the borehole wherein the settable material sets on at least a portion of the interior wall of the borehole to create a liner along the wall of the borehole and removing excess settable material out of the borehole.

Abstract: One embodiment of the invention is a variable density drilling mud comprising compressible particulate material in the drilling mud wherein the density of the drilling mud changes in response to pressure changes at depth. A second embodiment is a method for varying drilling mud density. The method comprises estimating the pore pressure and fracture gradient, and choosing a drilling mud with compressible materials wherein the effective mud weight of the drilling mud remains between the pore pressure and the fracture gradient in at least one interval of the wellbore. A third embodiment is an apparatus for drilling a wellbore.

Abstract: A process for drilling a well or a portion of a well capable of providing a generally constant interior wall diameter (monobore) and does not require installation of any liner or steel casing. The process comprises circulating settable material into the borehole wherein the settable material sets on at least a portion of the interior wall of the borehole to create a liner along the wall of the borehole and removing excess settable material out of the borehole.