A well image logging tool assembly comprising at least one sensor unit, at least one spatial positioning device, and a cylindrical outer sheath that extends around and contains the sensor unit and the spatial positioning device. The sensor unit includes a solid cylindrical sensor body formed of a gamma ray shielding material and including at least one longitudinal sensor cavity extending through at least one of the top end and the bottom end of the sensor body. A window corresponds to each sensor cavity and extends through the sensor body from the outside surface thereof to the corresponding sensor cavity. A sensor assembly is disposed in each sensor cavity. Each sensor assembly includes a gamma ray radiation sensor and associated photomultiplier tube.

A nuclear density tool may comprise a gamma source, a gamma detector, wherein the gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool, and a housing, wherein the gamma source and the gamma detector are disposed in the housing. The nuclear density tool may further comprise a first cutout in the housing positioned to allow the gamma source to emit an energy through the housing and a second cutout in the housing posited to allow the gamma detector to detect the energy through the housing. A method for determining a density may comprise disposing a nuclear density tool into a wellbore, transmitting an energy from the gamma source, detecting the energy reflected with the gamma detector, recording a count rate of the energy at the gamma detector, determining an average density based at least in part on the count rate, creating one or more layers from the average density, forming a layer construction using at least in part the one or more layers from the average density, comparing the layer construction to count rates form individual energy channels, and determining a final layer density for each of the one or more layers.

A nuclear density tool may comprise a gamma source, a gamma detector, wherein the gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool, and a housing, wherein the gamma source and the gamma detector are disposed in the housing. The nuclear density tool may further comprise a first cutout in the housing positioned to allow the gamma source to emit an energy through the housing and a second cutout in the housing posited to allow the gamma detector to detect the energy through the housing. A method for determining a density may comprise disposing a nuclear density tool into a wellbore, transmitting an energy from the gamma source, detecting the energy reflected with the gamma detector, recording a count rate of the energy at the gamma detector, determining an average density based at least in part on the count rate, creating one or more layers from the average density, forming a layer construction using at least in part the one or more layers from the average density, comparing the layer construction to count rates form individual energy channels, and determining a final layer density for each of the one or more layers.

The disclosure provides a well integrity monitoring tool for a wellbore, a method, using a nuclear tool and an EM tool, for well integrity monitoring of a wellbore having a multi-pipe configuration, and a well integrity monitoring system. In one example, the method includes: operating a nuclear tool in the wellbore to make a nuclear measurement at a depth of the wellbore, operating an EM tool in the wellbore to make an EM measurement at the depth of the wellbore, determining a plurality of piping properties of the multi-pipe configuration at the depth employing the EM measurement, determining, employing the piping properties, a processed nuclear measurement from the nuclear measurement, and employing the processed nuclear measurement to determine an integrity of a well material at the depth and within an annulus defined by the multi-pipe configuration.

The disclosure provides a well integrity monitoring tool for a wellbore, a method, using a nuclear tool and an EM tool, for well integrity monitoring of a wellbore having a multi-pipe configuration, and a well integrity monitoring system. In one example, the method includes: operating a nuclear tool in the wellbore to make a nuclear measurement at a depth of the wellbore, operating an EM tool in the wellbore to make an EM measurement at the depth of the wellbore, determining a plurality of piping properties of the multi-pipe configuration at the depth employing the EM measurement, determining, employing the piping properties, a processed nuclear measurement from the nuclear measurement, and employing the processed nuclear measurement to determine an integrity of a well material at the depth and within an annulus defined by the multi-pipe configuration.

The present invention belongs to the field of treatment for data identification and recording carriers, and specifically relates to a method and system for analyzing filling for a karst reservoir based on spectrum decomposition and machine learning, which aims to solve the problems that by adopting the existing petroleum exploration technology, the reservoir with fast lateral change cannot be predicted, and the development characteristics of a carbonate cave type reservoir in a large-scale complex basin cannot be identified. The method comprises: acquiring data of standardized logging curves; obtaining a high-precision 3D seismic amplitude data body by mixed-phase wavelet estimation and maximum posteriori deconvolution and enhancing diffusion filtering. According to the method and the system, the effect of identifying the development characteristics of the carbonate karst cave type reservoir in the large-scale complex basin can be achieved, and the characterization precision is improved.

The present invention belongs to the field of treatment for data identification and recording carriers, and specifically relates to a method and system for analyzing filling for a karst reservoir based on spectrum decomposition and machine learning, which aims to solve the problems that by adopting the existing petroleum exploration technology, the reservoir with fast lateral change cannot be predicted, and the development characteristics of a carbonate cave type reservoir in a large-scale complex basin cannot be identified. The method comprises: acquiring data of standardized logging curves; obtaining a high-precision 3D seismic amplitude data body by mixed-phase wavelet estimation and maximum posteriori deconvolution and enhancing diffusion filtering. According to the method and the system, the effect of identifying the development characteristics of the carbonate karst cave type reservoir in the large-scale complex basin can be achieved, and the characterization precision is improved.

A computer-implemented method that uses a preprogrammed neural network and a trained neural network computer program product to predict and then compared borehole and formation sigmas, when using a pulse neutron source and at least three dual-function radiation detectors. These dual-function radiation detectors are used for detecting both neutrons and gamma rays and further pre-programmed to distinguish between neutrons and gamma rays by using pulse shape discrimination techniques. The trained neural network computer program product can be used on above-surface systems, as well as below surface systems like borehole assemblies in logging-while-drilling systems. Once thermal neutron time-decay signals and capture gamma ray time-decay signals are measured by the at least three-dual function radiation detectors, a non-transitory computer readable memory device with the trained neural network computer program product is used to obtain a true borehole sigma and true formation sigma as the measurements are not affected by near-wellbore environments.

A computer-implemented method that uses a preprogrammed neural network and a trained neural network computer program product to predict and then compared borehole and formation sigmas, when using a pulse neutron source and at least three dual-function radiation detectors. These dual-function radiation detectors are used for detecting both neutrons and gamma rays and further pre-programmed to distinguish between neutrons and gamma rays by using pulse shape discrimination techniques. The trained neural network computer program product can be used on above-surface systems, as well as below surface systems like borehole assemblies in logging-while-drilling systems. Once thermal neutron time-decay signals and capture gamma ray time-decay signals are measured by the at least three-dual function radiation detectors, a non-transitory computer readable memory device with the trained neural network computer program product is used to obtain a true borehole sigma and true formation sigma as the measurements are not affected by near-wellbore environments.

The present disclosure relates to a downhole tool that includes a first photon flux detector disposed at a first radial position about a longitudinal axis of the downhole tool that measures a first signal indicative of an x-ray flux of the x-ray photons. The downhole tool also includes a second photon flux detector disposed at a second radial position about the longitudinal axis of the downhole tool that measures a second signal indicative of the x-ray flux of the x-ray photons. Further, the downhole tool includes a controller communicatively coupled to the first photon flux detector and the second photon flux detector that determines a condition associated with the electron beam based at least in part on a relative x-ray flux from the first photon flux detector and the second photon flux detector.