Abstract: A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Abstract: A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Abstract: A combustor includes at least one fuel nozzle extending from the end cover and at least partially surrounded by the forward casing. The combustor further includes a fuel injection assembly. The fuel injection assembly includes a fuel injector that extends through the outer sleeve, the annulus, and the combustion liner to the secondary combustion zone. A fuel supply conduit positioned outside of the outer sleeve. The fuel supply conduit extends to the fuel injector. The fuel injection assembly further includes a shielding assembly coupled to the outer sleeve and at least partially surrounding the fuel supply conduit. The shielding assembly includes a venturi nozzle having a circumferentially converging portion and a circumferentially diverging portion. At least one fuel sweep opening is defined in the outer sleeve and disposed within the shielding assembly.

Abstract: A method for evaluating hydraulic fracturing places distinctive tracers in each of the fractured regions around a number of production wellbores. For example, these tracers can by carried in the fracking fluid. Preferably, the tracers are embedded in the proppant material carried by the fracking fluid to more accurately reflect the extent of the resulting fractures. An observation wellbore is then drilled to transect these fractured regions in series. As drilling progresses into each fractured region, the distinctive tracer for that fractured region can be recovered in the observation wellbore. This information can be used to determine the location and extent of the fractured regions. Gaps or regions of overlap between adjacent fractured regions can also be identified. In addition, the observation wellbore allows other types of evaluation of the fractured regions, such as visual inspection of fractures by camera.