A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensor assemblies and a spatial positioning device is moved through at least a portion of the wellbore. Corrected gamma ray radiation data is vertically sampled. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.

Methods of elemental imaging of a formation include acquiring spectral gamma ray measurement, acquiring a total gamma ray image, deriving structure information of the formation from the total gamma ray image, and applying the structure information to the spectral gamma ray measurement to form an elemental image. In the present methods, the structure information of the formation is derived from comparing the total gamma ray logs for each azimuthal sector to a derived total gamma ray log. The derived total gamma ray log is acquired from the total gamma ray image by summing over all azimuth bins or the spectral gamma ray measurement by summing over all energy bins.

Presented herein are systems, methods, and nonvolatile computer-readable storage devices for informing a particle event processor of a particle detector of events arising within a sensor period. The systems, methods, and nonvolatile computer-readable storage devices involve the generation of a sensor data set detected by a particle event sensor and representing the events arising within the particle detector during the sensor period. The systems, methods, and nonvolatile computer-readable storage devices also involve the compression of the sensor data set with a waveform compression technique to generate a compressed sensor data set, and the transmission of the compressed sensor data set to the particle event processor.

A single crystal yttrium aluminum perovskite scintillator has a minimum thickness of at least 5 mm and a transmittance of at least 50% at a wavelength of 370 nm. A method for fabricating the yttrium aluminum perovskite scintillator includes acquiring a yttrium aluminum perovskite single crystal boule, annealing the yttrium aluminum perovskite single crystal boule in an oxygen containing environment to obtain a partially annealed crystal, and annealing the partially annealed crystal in an inert environment or a reducing environment to obtain the yttrium aluminum perovskite single crystal scintillator.

In some embodiments, a method for transposition of logs onto a horizontal well path may include collecting vertical situational data from a plurality of depths of a vertical well in a geological formation and collecting horizontal situational data from a plurality of locations along the horizontal well path in the geological formation. The method further includes collecting geological data associated with the plurality of depths of the vertical well and generating pseudo-logs for the horizontal well path based on the plurality of depths and the associated geological data for the plurality of depths.

A method for quality control of gamma-gamma well logging data within a borehole for mineral exploration, including receiving, at a computing device, raw well logging data; identifying and formatting data sets from the raw well logging data; applying at least one quality control process to the formatted data sets, the at least one quality control process being selected from: a linear verification process comparing linearity of density data readings between a long and a short spaced sensor in a probe; a density range verification process comparing density readings at the probe with density ranges for the borehole lithology; a diameter comparison process comparing actual diameter of the borehole at a depth with density readings at the depth; and a residual verification process for verifying a proportionality between densities measured by the long spaced sensor and short spaced sensor; compiling the results and providing an output of the compiled results.

An x-ray-based reservoir evaluation tool for the measurement of the shale density anticipated at shale-creep barrier within a cased borehole is disclosed, wherein the tool includes an internal length comprising a sonde section, wherein the sonde section further includes an x-ray source; a plurality of radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs. A method of using an x-ray-based shale-seal evaluation tool for measuring the shale density anticipated at shale-creep barrier within a cased borehole is also disclosed, the method including: using x-rays to illuminate the formation surrounding the cased borehole; using detectors to directly measure the density of the formation; using detectors to directly measure the effects on the measurement from tool stand-off or production liner attenuation; and compensating for the production liner and liner-annular region when computing the saturated formation density within the production interval.

Embodiments presented provide for an apparatus and method for characterizing linear and annulus properties using a gamma-gamma tool.

A method for evaluating wellbore conduit condition includes using measurements of at least one of (i) inelastic gamma rays made during emission a burst of neutrons into the conduit from within the conduit at at least one spaced apart location from a position of the emission and (ii) epithermal neutrons or capture gamma rays therefrom detected at at least two spaced apart locations from the position of the emission within a selected time after the emission. The at least one of the measurements of inelastic gamma rays and epithermal neutron or capture gamma ray counts are characterized to estimate an amount of loss of iron in the conduit.

The subject technology relates to estimating borehole contributions to measured calcium and sulfur elemental yields by using a small number of mud properties available from wellsite mud reports at the time of logging. Neutron-induced gamma ray spectroscopy logs may be measured and, more specifically, estimating the borehole contributions to the measured calcium and sulfur elemental yields. The subject technology provides for predicting relative borehole yields as a function of borehole size and a set of properties that describe the composition of various complex drilling mud mixtures based on the elemental atomic number density for the drilling mud. The subject technology generates borehole bias vectors from analysis of the simulated tool responses, and applies a borehole bias vector to a relative elemental yield vector to correct a calcium yield and/or a sulfur yield. Other methods, systems, and computer-readable media are also disclosed.