Abstract: A free point tool comprises an elongated main shaft assembly and a low mass sensor assembly coaxially and slidingly disposed over the elongated main shaft. The low mass sensor assembly is adapted to be supported within the down hole casing by first and second drag spring centralizers coupled respectively to upper and lower ends of the low mass sensor assembly. The low mass sensor assembly comprises a magnetic amplifier sensor disposed in a sensor body and having a variable inductance proportionally responsive to longitudinal and rotational displacement of an adjacent sensor plate portion of a movable sensor sleeve concentric with and enclosing the sensor body, wherein the sensor sleeve is attached to the first drag spring centralizer and the sensor body is attached to the second drag spring centralizer.

Abstract: An improved structural system of cooperating building components including premolded, interlocking block units having configurable interlocking components and passage configuration components. The block units are disposed end-to-end in a plurality of stacked, interlocking courses to form a configurable plurality of horizontal and vertical passageways for receiving material. The interlocking components and configuration components enable adjacent courses of the premolded block units to be vertically aligned and longitudinally interlocked. Horizontal passageways within a course are also configured for receiving material, for being fully closed to receiving material, or for being both partially closed to receiving a selected first material and partially open for receiving a selected second material, according to the orientation of the configuration and interlocking components.

Abstract: A free point tool comprises an elongated main shaft assembly and a low mass sensor assembly coaxially and slidingly disposed over the elongated main shaft. The low mass sensor assembly is adapted to be supported within the down hole casing by first and second drag spring centralizers coupled respectively to upper and lower ends of the low mass sensor assembly. The low mass sensor assembly comprises a magnetic amplifier sensor disposed in a sensor body and having a variable inductance proportionally responsive to longitudinal and rotational displacement of an adjacent sensor plate portion of a movable sensor sleeve concentric with and enclosing the sensor body, wherein the sensor sleeve is attached to the first drag spring centralizer and the sensor body is attached to the second drag spring centralizer.

Abstract: An apparatus and method of determining the point at which a tubular is stuck within another tubular or a wellbore by applying a tensile or torsional force to the stuck tubular and measuring the response of various locations within the tubular. In addition, the apparatus may be combined with a cutting tool to separate the free portion of the tubular from the stuck portion.