Methods of downhole testing subterranean formations and associated apparatus therefor

A well testing system, comprising:

• a tubular string having a surge chamber interconnected as a portion thereof, an axial flow passage formed through the tubular string, and first and second valves, the axial flow passage being divided into first, second and third portions, the first valve separating the first portion from the second portion, the second portion being disposed within the surge chamber between the first and second valves, and the second valve separating the second portion from the third portion;
• and
• a circulating valve interconnected in the tubular string, the circulating valve selectively permitting fluid communication between the flow passage third portion and the exterior of the tubular string, and
• wherein the circulating valve is positioned between the surge chamber and a perforating gun.

A method of testing a subterranean formation intersected by a wellbore, the method comprising the steps of:

• positioning a tubular string within the wellbore, the tubular string having a surge chamber interconnected as a portion thereof, an axial flow passage formed through the tubular string, and first and second valves, the axial flow passage being divided into first, second and third portions, the first valve separating the first portion from the second portion, the second portion being disposed within the surge chamber between the first and second valves, and the second valve separating the second portion from the third portion;
• placing the flow passage third portion in fluid communication with the formation;
• opening the second valve, thereby placing the surge chamber in fluid communication with the formation;
• receiving a sample of fluid from the formation in the surge chamber;
• and
• circulating the sample to the earth's surface.

A method of testing a subterranean formation intersected by a wellbore, the method comprising the steps of:

• positioning a tubular string within the wellbore, the tubular string having a surge chamber interconnected as a portion thereof, an axial flow passage formed through the tubular string, and first and second valves, the axial flow passage being divided into first, second and third portions, the first valve separating the first portion from the second portion, the second portion being disposed within the surge chamber between the first and second valves, and the second valve separating the second portion from the third portion;
• placing the flow passage third portion in fluid communication with the formation;
• opening the second valve, thereby placing the surge chamber in fluid communication with the formation;
• receiving a sample of fluid from the formation in the surge chamber;
• and
• opening the first valve and flowing the sample back into the formation.

A method of testing a subterranean formation intersected by a wellbore, the method comprising the steps of:

• positioning a tubular string within the wellbore, the tubular string having a surge chamber interconnected as a portion thereof, an axial flow passage formed through the tubular string, and first and second valves, the axial flow passage being divided into first, second and third portions, the first valve separating the first portion from the second portion, the second portion being disposed within the surge chamber between the first and second valves, and the second valve separating the second portion from the third portion;
• placing the flow passage third portion in fluid communication with the formation;
• and
• placing a waste chamber in fluid communication with the formation.

A method of testing a subterranean formation intersected by a wellbore, the method comprising the steps of:

• positioning a tubular string within the wellbore, the tubular string having a surge chamber interconnected as a portion thereof, an axial flow passage formed through the tubular string, and first and second valves, the axial flow passage being divided into first, second and third portions, the first valve separating the first portion from the second portion, the second portion being disposed within the surge chamber between the first and second valves, and the second valve separating the second portion from the third portion;
• placing the flow passage third portion in fluid communication with the formation;
• and
• installing a fluid sampler in fluid communication with the surge chamber, the fluid sampler having a separate volume from the surge chamber.