Patent ID: 7703318

Claim:
A formation tester for determining the formation pressure of a subsurface formation traversed by a wellbore, said formation tester comprising: an elongate tester body ( 1 ); a support plate ( 3 ) that is extendible outwardly from the surface of the formation tester body using a probe positioner ( 4 ), said support plate carrying probe means ( 5 ) to establish a passageway between the inside of said formation tester body and said formation, and a sealing pad ( 6 ) connected to said probe means to isolate said passage way between the inside of said formation tester body and said formation; anchoring means ( 7 ) to settle said tester body at a level within the wellbore; wherein said elongate tester body comprises an eccentric portion ( 2 ) wherein said support plate is mounted such that a determined standoff is maintained between said elongate tester body ( 1 ) and the wall ( 8 ) of the wellbore when said tester body is settled at a level in the wellbore, and wherein additional standoff means ( 11 ) are secured on said elongate tester body, said additional standoff means being removable, and wherein the anchoring means ( 7 ) are situated on the side of the tester body opposite to the support plate and wherein there is an imbalance between the anchoring force and the force applied by the probe positioner ( 4 ) such that the only contact with the wall of the wellbore will be the eccentric portion.