Abstract: A portable system for reworking the inside diameter of oil field pipe and casing, and especially plastic coated pipe that is to be re-coated. The system includes a grinderhead that removes irregularities from the inner surface of the pipe to render the pipe suitable for use in deep wells. A cutterhead assembly is rotated as it is forced into the interior of a joint of pipe. The cutterhead assembly includes a mandrel which turns a special cutting device having a plurality of grinders for engaging and cutting the inner wall of the pipe as the entire grinderhead is forced to travel through the pipe. Alignment and grinding members attached to the mandrel maintain the longitudinal axis of the grinders in proper alignment to produce the desired new pipe inside diameter. Included in the system is a special cutterhead for removing old plastic coating material in advance of the grinderhead whereby the cutterhead mostly removes plastic while the grinderhead mostly removes metal from the inner pipe surface.

Abstract: A portable system for reworking the inside diameter of heavy oil field casing, and especially casing that has irregularities on the inner surface thereof that render the casing unsuitable for use in deep wells. A cutting head assembly is rotated as it is forced into the interior of a joint of casing. The cutting head assembly includes a mandrel which turns a special cutting device having a plurality of cutters for engaging and cutting the inner wall of the pipe as the entire cutterhead is forced to travel through the pipe. Alignment members attached to the mandrel on either side of the cutting device maintain the longitudinal axis of the cutters in proper alignment to produce the desired new pipe inside diameter. After the first half of the pipe is sized or trued, the joint of casing is reversed and the other half is cut to the same new desired inside diameter. Included in the system is a special grinder for reworking pipe having only marginal imperfections.

Abstract: A portable system for reworking the inside diameter of heavy oil field casing, and especially casing that has irregularities on the inner surface thereof that render the casing unsuitable for use in deep wells. A cutting head assembly is rotated as it is forced into the interior of a joint of casing. The cutting head assembly includes a mandrel which turns a special cutting device having a plurality of cutters of engaging and cutting the inner wall of the pipe as the entire cutterhead is forced to travel through the pipe. Alignment members attached to the mandrel on either side of the cutting device maintain the longitudinal axis of the cutters in proper alignment to produce the desired new pipe inside diameter. After the first half of the pipe is sized or trued, the joint of casing is reversed and the other half is cut to the same new desired inside diameter.