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A high energy gas fracturing tool for radially fracturing a rock formation in a well bore consisting of a cylindrical canister that is holed to pass gas and is for housing a stack of propellant modules that are selected to provide a desired burn rate when ignited. Each propellant module mating face

A high energy gas fracturing tool for radially fracturing a rock formation in a well bore consisting of a cylindrical canister that is holed to pass gas and is for housing a stack of propellant modules that are selected to provide a desired burn rate when ignited. Each propellant module mating face is angled from the horizontal between forty-five (45) to seventy-five (75) degrees, and the modules are bonded together with an epoxy resin wherein propellant or explosive particles are mixed, the resin to exhibit burn characteristics similar to those of the propellant stack. The tool, additional to the propellant containing canister, an ignitor rod and explosive device for igniting the propellant stack, mounts a bull head end over a lower end and a reverse thruster assembly that is connected to the canister upper end. The reverse thruster assembly includes a housing with nozzles formed therein that are angled from the vertical to pass gas on propellant deflagration, creating thereby a force against the tool lifting during propellant burning. Above the reverse thruster assembly is arranged a pressure pulse monitor that is battery powered to operate a pressure transducer for sensing pressure pulses at the tool. The monitor to turn on when a sufficient strength of pressure pulse is received, to store pressure pulses sensed over time, with the stored pressure data retrieved when the tool is removed from the well bore. The recorded pressure pulse data is used for determining the dynamic window of the formation, whereat, at a certain pressure over time the formation will be optimally radially fractured. The tool is suspended from the surface on a wire line and includes a collar locator for locating it at a certain level within the well bore.

대표청구항 ▼

A tool for stimulating a subterranean formation comprising, an elongate propellant stack constructed from propellant material modules that are formed from a combination of propellant materials such that the propellant module combination will have a desired burn rate, propellant modules of a center p

A tool for stimulating a subterranean formation comprising, an elongate propellant stack constructed from propellant material modules that are formed from a combination of propellant materials such that the propellant module combination will have a desired burn rate, propellant modules of a center portion to have identical convex and concave surfaces as the respective top and bottom faces thereof with end propellant modules to form the propellant stack ends each having an end face to fit within or over one of said center portion propellant modules convex or concave faces; adhesive means containing grains of a propellant or explosive mixed therein to provide a burn rate that is approximately that of the propellant stack for bonding said selected propellant modules together, said adhesive means to burn with the propellant stack; means for supporting and lowering said propellant stack into a well bore to a subterranean formation to be stimulated; and means for igniting said propellant stack.