Method and apparatus for determining downhole pressures during a drilling operation

A method and apparatus is provided to determine downhole pressures, such as annular pressure and/or pore pressure, during a drilling operation. A bottom hole assembly (BHA) of a downhole tool includes one or more pressure equalizing assemblies capable of registering the pore pressure when the BHA is at rest and in contact with the wellbore, and annular pressure of a wellbore when it is not. Wellbore fluid is permitted to enter the pressure equalizing assembly and register an annular pressure measurement. Once the BHA comes into contact with the wellbore and to rest, fluid communication is established between the pressure equalizing assembly and the formation to generate a pore pressure measurement. The pressure equalizing assembly includes a sliding valve selectively moveable between an open and closed position in response to operation of the BHA so that the desired pressure measurement may be taken.