Abstract: Methods and associated systems are disclosed for performing a logging operation within a subterranean wellbore extending within a subterranean reservoir. In an embodiment, the method includes (a) emitting neutrons into the subterranean wellbore or the subterranean reservoir, and (b) detecting gamma rays emitted from atoms disposed within the subterranean wellbore or the subterranean reservoir. In addition, the method includes (c) determining a first gamma ray count within a first energy window of the gamma rays detected at (b), and (d) determining a second gamma ray count within a second energy window of the gamma rays detected at (b). The second energy window is different than the first energy window. Further, the method includes (e) calculating a ratio of the first gamma ray count to the second gamma ray count.

Abstract: An erosive jet can propel degradable, abrasive grit conveyed in a carrier fluid to erode a downhole structure, such as a tubular (e.g., cutting through a tubular) or formation (e.g., perforation actions). The abrasive grit can be selected to degrade or dissolve in the wellbore fluid (e.g., in carrier fluid pumped into the wellbore or in fluid originating from the wellbore). The abrasive grit can provide increased cutting or erosion efficiency in the erosive jet during the cutting operation, then may degrade (e.g., dissolve) in the wellbore fluid to avoid certain complications, such as clogging or residue build-up in the wellbore formation or on downhole equipment. A degradation accelerator can be introduced (e.g., in carrier fluid) to accelerate degradation of the abrasive grit in the wellbore fluid. Degradation accelerators can be temperature-activated, pH-activated, or otherwise time-delayed so the abrasive grit remains sufficiently intact to perform the desired erosion operation.

Abstract: Methods and associated systems are disclosed for performing a logging operation within a subterranean wellbore extending within a subterranean reservoir. In an embodiment, the method includes (a) emitting neutrons into the subterranean wellbore or the subterranean reservoir, and (b) detecting gamma rays emitted from atoms disposed within the subterranean wellbore or the subterranean reservoir. In addition, the method includes (c) determining a first gamma ray count within a first energy window of the gamma rays detected at (b), and (d) determining a second gamma ray count within a second energy window of the gamma rays detected at (b). The second energy window is different than the first energy window. Further, the method includes (e) calculating a ratio of the first gamma ray count to the second gamma ray count.

Abstract: An erosive jet can propel degradable, abrasive grit conveyed in a carrier fluid to erode a downhole structure, such as a tubular (e.g., cutting through a tubular) or formation (e.g., perforation actions). The abrasive grit can be selected to degrade or dissolve in the wellbore fluid (e.g., in carrier fluid pumped into the wellbore or in fluid originating from the wellbore). The abrasive grit can provide increased cutting or erosion efficiency in the erosive jet during the cutting operation, then may degrade (e.g., dissolve) in the wellbore fluid to avoid certain complications, such as clogging or residue build-up in the wellbore formation or on downhole equipment. A degradation accelerator can be introduced (e.g., in carrier fluid) to accelerate degradation of the abrasive grit in the wellbore fluid. Degradation accelerators can be temperature-activated, pH-activated, or otherwise time-delayed so the abrasive grit remains sufficiently intact to perform the desired erosion operation.