Patent ID: 8752650

Claim:
A method of conducting a drill stem test of a geological test zone using a downhole tool that is run into a drill string to conduct the test, comprising: utilising a wireline coring drill string system of the type employing a coring drill bit and a core barrel; drilling a borehole using the coring drill bit, and then raising the coring drill bit to define a test zone in the borehole below the raised coring drill bit; utilizing a first inflatable packer, a second inflatable packer and a valve as at least a part of the downhole tool; conveying the downhole tool via a wireline system into the drill string; lowering the downhole tool so that the first inflatable packer is placed at a location beyond a bottom of the coring drill bit, the first inflatable packer located so that it engages with and seals the borehole on one side of the test zone; utilising the second inflatable packer to seal the downhole tool to the core barrel; holding the valve in the core barrel by the second inflatable packer, and utilising the valve to control the passage therethrough of fluid flowing through the second inflatable packer; moving the drill string to open and close the valve within the downhole tool to permit fluid flow to and from the test zone to the inside of the drill string; and analysing parameters of the gas and liquid obtained from the geological test zone.