Abstract: Zonal isolation of well bores is often desirable for performing downhole operations such as stimulation operations. In certain embodiments, diverter plugs for achieving zonal isolation in a casing string in a well bore may comprise a mandrel having a first end and a second end; a compressible body attached to and surrounding a longitudinal portion of the mandrel; and a sealing nose attached to the first end of the mandrel. In certain embodiments, systems for achieving zonal isolation of a casing string in a well bore may comprise a diverter plug comprising a mandrel having a first end and a second end, a compressible body attached to and surrounding a longitudinal portion of the mandrel, and a sealing nose attached to the first end of the mandrel; and a landing collar sized to mate with a portion of the sealing nose of the diverter plug. Associated methods are also provided.

Abstract: Pulsed power sources are installed in one or more wells in the reservoir interval. The pulse sources include (1) an electrohydraulic generator that produces an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir, and an acoustic pulse from the plasma vaporization of water placed around the source that propagates through the reservoir at the speed of sound in the reservoir and (2) an electromagnetic generator that produces only an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir. The combination of electrohydraulic and electromagnetic generators in the reservoir causes both the acoustic vibration and electromagnetically-induced high-frequency vibrations occur over an area of the reservoir where stimulation is desired.

Abstract: Pulsed power sources are installed in one or more wells in the reservoir interval. The pulse sources include (1) an electrohydraulic generator that produces an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir, and an acoustic pulse from the plasma vaporization of water placed around the source that propagates through the reservoir at the speed of sound in the reservoir and (2) an electromagnetic generator that produces only an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir. The combination of electrohydraulic and electromagnetic generators in the reservoir causes both the acoustic vibration and electromagnetically-induced high-frequency vibrations occur over an area of the reservoir where stimulation is desired.

Abstract: An aircraft wing box construction including canted sheet metal spar webs continuously tied to the upper and lower skins. Sheet metal intercostal stiffeners of substantially triangular configuration are spaced spanwise along the web to provide shear stiffening for the web and intermittent stabilization for the upper skin. Both the shear web and intercostal stiffeners are fastened to spanwise continuous spar caps which are attached to the upper and lower skins. These caps, supported by the intercostals and webs, provide sufficient stabilization to prevent upper skin buckling up to ultimate design stress with a minimum of shear webs thereby providing significant weight savings.