Abstract: Downhole stimulation tools include a housing and at least one propellant structure within the housing comprising at least one propellant grain of a formulation, at least another propellant grain of a formulation different from the formulation of the at least one propellant grain longitudinally adjacent the at least one propellant grain, and at least one initiation element proximate at least one of the propellant grains. At least one pressure containment structure is secured to the housing and comprises a seal element expandable in response to gas pressure generated by combustion of a propellant grain of the at least one propellant structure. Related methods are also disclosed.

Abstract: A downhole stimulation tool comprising an outer housing exhibiting apertures extending therethrough, opposing propellant structures within the outer housing, and at least one initiator adjacent each of the opposing propellant structures. Each of the opposing propellant structures comprise at least one higher combustion rate propellant region, and at least one lower combustion rate propellant region longitudinally adjacent the at least one higher combustion rate propellant region. Additional downhole stimulation tools and methods of stimulating a producing formation are also disclosed.

Abstract: Propellant structures and stimulation tools incorporating propellant structures may comprise composite propellant structures including two or more regions of propellant having different compositions, different grain structures, or both. An axially extending initiation bore containing an initiation element may extend through a center of the propellant structure, or may be laterally offset from the center. An offset initiation bore may be employed with a composite grain structure. Methods of tailoring ballistic characteristics of propellant burn to result in desired operational pressure pulse characteristics are also disclosed.

Abstract: Downhole stimulation tools include a housing and at least one propellant structure within the housing comprising at least one propellant grain of a formulation, at least another propellant grain of a formulation different from the formulation of the at least one propellant grain longitudinally adjacent the at least one propellant grain, and at least one initiation element proximate at least one of the propellant grains. At least one pressure containment structure is secured to the housing and comprises a seal element expandable in response to gas pressure generated by combustion of a propellant grain of the at least one propellant structure. Related methods are also disclosed.

Abstract: A downhole stimulation tool comprising an outer housing exhibiting apertures extending therethrough, opposing propellant structures within the outer housing, and at least one initiator adjacent each of the opposing propellant structures. Each of the opposing propellant structures comprise at least one higher combustion rate propellant region, and at least one lower combustion rate propellant region longitudinally adjacent the at least one higher combustion rate propellant region. Additional downhole stimulation tools and methods of stimulating a producing formation are also disclosed.

Abstract: Propellant structures and stimulation tools incorporating propellant structures may comprise composite propellant structures including two or more regions of propellant having different compositions, different grain structures, or both. An axially extending initiation bore containing a initiation element may extend through a center of the propellant structure, or may be laterally offset from the center. An offset initiation bore may be employed with a composite grain structure. Methods of tailoring ballistic characteristics of propellant burn to result in desired operational pressure pulse characteristics are also disclosed.

Abstract: Methods and apparatus for allowing a traffic level switch associated with an automatic protection switching (APS) topology to occur transparently and without reconverging routing are described. According to one aspect of the present invention, a method for providing protection switching configuration information associated with a router arrangement to includes identifying a first interface and a second interface of the router arrangement as an APS group. The method also includes providing information regarding the APS group to a process that implements a routing protocol. Providing the information regarding the group includes identifying the first interface as a primary interface and identifying the second interface as a backup interface that is arranged to protect the primary interface.

Abstract: Methods and apparatus for allowing a traffic level switch associated with an automatic protection switching (APS) topology to occur transparently and without reconverging routing are described. According to one aspect of the present invention, a method for providing protection switching configuration information associated with a router arrangement to includes identifying a first interface and a second interface of the router arrangement as an APS group. The method also includes providing information regarding the APS group to a process that implements a routing protocol. Providing the information regarding the group includes identifying the first interface as a primary interface and identifying the second interface as a backup interface that is arranged to protect the primary interface.

Abstract: A system and method for shattering a launch vehicle into relatively small pieces are described. The launch vehicle includes at least one solid fuel rocket motor having a propellant disposed about a combustion chamber within a rocket motor case. Each rocket motor also includes at least one motor igniter to ignite the propellant and at least one explosive charge adjacent the rocket motor case. A firing unit is capable of generating a motor ignition signal and a charge explosion signal. A first propagator carries the motor ignition signal to the motor igniter so the signal arrives after a propagation time T.sub.ignition and causes ignition of the previously unignited rocket motor. A second propagator carries the charge explosion signal to the explosive charge so the signal arrives after a propagation time T.sub.explosion and causes an explosion against the rocket motor case. The time T.sub.explosion is greater than the time T.sub.ignition by a pressurization time T.sub.