Patent ID: 8033333

Claim:
A downhole tool for subsurface fracturing, comprising: first and second propellant assemblies, each propellant assembly comprising: a first tubular member having an annulus formed therethrough; a second tubular member at least partially disposed within the annulus of the first tubular member; one or more tubular propellants housed within the first tubular member, between an inner diameter of the first tubular member and an outer diameter of the second tubular member; one or more detonating cords housed within the second tubular member, wherein the second tubular member has one or more portions thereof having a reduced wall thickness, wherein the first and second tubular members are substantially concentric to one another; and first and second end connectors disposed at opposite ends of the first tubular member, wherein the second tubular member has threaded ends adapted to engage the first and second end connectors; a male coupler having a first side and a second side, the second side being adapted to be received into the first end connector of either one of the first and second propellant assemblies; a female coupler having a first side and a second side, the second side being adapted to receive the second end connector of either one of the first and second propellant assemblies; and a transfer sub housing disposed between the first and second propellant assemblies, the transfer sub housing having first and second ends, wherein the first sides of the male and female couplers are adapted to couple to either of the first and second ends of the transfer sub housing.