Abstract: A mandrel for an isolation tool for completion of oil and gas wells and a method for making the mandrel is disclosed. The mandrel comprising a composite tube, wherein the composite tube has an inner diameter; wherein a first section of the composite tube has a first outer diameter and a second section has a second outer diameter, wherein the first end has a beveled surface defined by a first angle with an interior surface of the composite tube, wherein the composite tube is made from a plurality of layers of fibers coated with a chemical matrix. The method comprises interweaving a plurality of layers of fibers around a core, coating the plurality of layers of fibers with a chemical matrix to form a composite tube, curing the composite tube, milling or grinding the outer surface of the composite tube to form a mandrel, and removing the core.

Abstract: A system according to the present invention may be comprised of an epoxy resin, hardener and catalyst. One particular preferred system ratio is 1:1.64:0.005, respectively. The epoxy resin may be a tetrafunctional resin. The hardner may be a nadic methyl anhydride. One particularly preferred heat activated catalyst is 1-(2-hydroxypropyl) imidazole available from the Lindau Company under the brand name LINDAX 1. The amount of catalyst may be tailored to a certain desired pot life, oven cure and to promote polymer crosslinking at a faster rate. The system is particularly advantageous in the fabrication of composite bridge plugs.