Abstract: Apparatus for measuring the profile of a wellbore includes a cylindrical body having first and second ends threaded for connection in line with a drill string. A passage extends through the body between the first and second ends. A plurality of arms are pivotally coupled on an outer surface of the cylindrical body. Each of the arms is biased to pivot so as to move a free end thereof radially away from the outer surface of the body. The plurality of arms are angularly spaced apart around the cylindrical body and arranged in a plurality of tiers. Each of the tiers comprises three or more of the arms. The tiers are spaced apart axially from one another along the cylindrical body. Sensors are operable to directly or indirectly measure radial extension of each of the arms from the cylindrical body. A holding mechanism is operable to hold the arms in a retracted configuration and to selectively release the arms to pivot away from the cylindrical body.

Abstract: There is provided a wellbore measuring apparatus according to one aspect. The wellbore measuring apparatus includes an outer body that is tubular with spaced-apart ends threaded for connection in line with a drill string. The outer body has a plurality of recesses extending around the outer surface thereof in one or more helical patterns. The wellbore measuring apparatus includes a plurality of sensors operatively coupled to and each positioned within a respective said recess of the outer body. Each sensor is arranged to measure at least one characteristic of a wellbore. The wellbore measuring apparatus may include at least one rib coupled to and extending radially outwards from the outer surface of the outer body. The at least one rib is helical in shape and with the plurality of sensors extending along and being adjacent to the at least one rib.

Abstract: Apparatus for measuring the profile of a wellbore includes a cylindrical body having first and second ends threaded for connection in line with a drill string. A passage extends through the body between the first and second ends. A plurality of arms are pivotally coupled on an outer surface of the cylindrical body. Each of the arms is biased to pivot so as to move a free end of the arm to move radially away from the outer surface of the body. The plurality of arms are angularly spaced apart around the cylindrical body and arranged in a plurality of tiers. Each of the tiers comprises three or more of the arms. The tiers are spaced apart axially from one another along the cylindrical body. Sensors are operable to directly or indirectly measure radial extension of each of the arms from the cylindrical body. A holding mechanism is operable to hold the arms in a retracted configuration and to selectively release the arms to pivot away from the cylindrical body.

Abstract: An apparatus for measuring a well bore wall comprises a casing connectable in line with a tool string having a central passage therethrough and extending between first and second ends and a plurality of longitudinally extending biasing elements extending longitudinally along the casing between first and second ends wherein each of the second end of the biasing elements is connected to the casing. The apparatus further comprises a sensor located along a midpoint of each of the biasing elements and an engagement body located within the central passage of the casing longitudinally displaceable therein between first and second positions, wherein the engagement body is connected to the first end of each of the biasing elements such that displacement of the engagement body within the central passage from the first to the second positions compresses and radially extends the biasing elements so as to engage the sensors against the well bore wall.