One-trip well perforation/proppant fracturing apparatus and methods

Abstract

In a subterranean well a one-trip production zone perforation and proppant fracturing operation is carried out using a workstring-supported perforation gun lowered into a casing nipple located in the production zone. Firing of the gun creates spaced apart aligned sets of perforations extending outwardly through a side wall portion of the workstring, the nipple, the surrounding cement, and into the production zone, after which the gun falls into and is retained in an underlying gun catcher portion of the workstring. While an axial tension or compression force is imposed on the workstring above the aligned perforations to maintain their alignment, a proppant slurry is pumped down the workstring, out its sidewall perforations, and outwardly through the aligned perforation sets formed in the nipple, cement and production zone. After stimulation of the production zone, the workstring and the spent perforation gun that it retains are pulled up, with the upwardly moving workstring positioning a sliding closure device inwardly over the perforations to isolate the stimulated production zone until the well is readied for production. Illustrated alternate embodiments include the use of a low debris casing gun in place of the drop-off type perforating gun, the use of pre-formed perforations in the workstring side wall, and a one-trip perforation and production flow creating method in which the production zone stimulating step is eliminated.