Plug and Gun Apparatus and Method for Cementing and Perforating Casing

Abstract

An apparatus is used in cementing and perforating casing in a borehole. A cement head disposed on the casing has first and second containers. A first plug positioned in the first container deploys from the cement head in the casing in advance of cement slurry. An assembly positioned in the second container deploys from the cement head in the casing after the cement slurry. The first plug lands on a float collar on the casing, and a breachable passage in the first plug opens and allows the cement slurry to pass into the borehole annulus. The assembly has a wiper and has one or more charges. The wiper wipes the casing as the assembly is displaced down the casing with displacing fluid. Eventually, the assembly lands at the first plug, and hydraulic pressure applied in the casing activates the one or more charges to perforate the casing.

Dependencies are inferred from the claim text.