A system for investigating the condition of a tubular string

A system for determining the condition of a tubular string, comprising:

• an elongate body having a proximal end, a distal end and a center axis extending through the proximal end and the distal end;
• a connector coupled to the proximal end of the body to couple the body to a distal end of an elongate conduit that can be used to position the body within a tubular string;
• a data storage device to receive and store signals generated by sensors disposed on or within the body;
• an inclination sensor coupled to the data storage device to detect and to generate a signal indicating an angle of the center axis of the body relative to gravity;
• a plurality of angularly distributed inductive distance sensors coupled to the data storage device, each of the plurality of inductive distance sensors to generate a signal indicating the distance from the inductive distance sensor to an interior wall of a bore of a tubular string in which the body is positioned;
• an accelerometer coupled to the data storage device to generate a signal indicating the acceleration of the body;
• and
• an electrical power storage source coupled to each of the plurality of inductive sensors, the inclination sensor, the accelerometer;
• wherein the length of the conduit fed into the bore of the tubular string can be used to determine the position of the body within the bore of the tubular string;
• wherein the signals generated by the plurality of inductive distance sensors can be correlated with the position of the body within the bore of the tubular string to determine the ovality of the bore of the tubular string adjacent to the plurality of inductive distance sensors and a build-up of scale on the interior surface of the bore of the tubular string adjacent to the plurality of inductive distance sensors;
• wherein the signals generated by the accelerometer can be correlated with the position of the body within the bore of the tubular string to determine of an obstruction that impedes smooth movement of the body through the bore of the tubular string;
• and
• wherein signals generated by the inclination sensor can be correlated with the signals generated by the plurality of inductive distance sensors to determine whether a separation of the body from the interior surface of the tubular string is due to scale.