Computing system assessment of geological similarity of wells employing well-log data includes receiving logs with chronostratigraphic markers, and extracting signatures from the logs using the chronostratigraphic markers. A distance matrix is generated from the signatures using dynamic time warping. Using the distance matrix, a set of clusters are generated. The set of clusters are presented with an image.

A method includes receiving a drilling parameter, a tool characterization parameter, and a formation model. The method includes generating a forward model of a tool response at a bed boundary using the one drilling parameter, the tool characterization parameter, and the formation model. The method includes predicting at least two azimuthal gamma logs using the forward model. The method includes determining that a difference between the at least two azimuthal gamma logs generates a confidence level that is greater than a confidence threshold. In response to determining that the difference between the at least two azimuthal gamma logs generates the confidence level that is greater than the confidence threshold, the method includes generating a well plan. The method includes outputting a command for controlling a trajectory in directionally drilling a wellbore within a formation associated with the formation model using the well plan.

A system, method, and apparatus for wellbore inspection comprise an electron accelerator to generate X-rays, a rotating collimator assembly configured to produce a cone of X-rays, and at least one detector assembly configured to collect backscattered X-rays. A position assembly can be provided to move the electron accelerator, rotating collimator assembly, and detector through a wellbore. A computer system is configured to receive data from the detector and generate an image of the wellbore.

A method includes receiving a drilling parameter, a tool characterization parameter, and a formation model. The method includes generating a forward model of a tool response at a bed boundary using the one drilling parameter, the tool characterization parameter, and the formation model. The method includes predicting at least two azimuthal gamma logs using the forward model. The method includes determining that a difference between the at least two azimuthal gamma logs generates a confidence level that is greater than a confidence threshold. In response to determining that the difference between the at least two azimuthal gamma logs generates the confidence level that is greater than the confidence threshold, the method includes generating a well plan. The method includes outputting a command for controlling a trajectory in directionally drilling a wellbore within a formation associated with the formation model using the well plan.

Methods, tools, and systems for determining porosity in an earth formation are disclosed. Neutrons are emitted into the formation to induce inelastic scattering gamma rays and thermal capture gamma rays in the formation. The induced gamma rays are detected at a proximal gamma detector and a far gamma detector, which are spaced at different axial distances from the neutron source. A measured proximal-to-far inelastic ratio (a ratio of inelastic scattering gammas detected at the proximal and far detector) and a proximal-to-far thermal capture ratio (a ratio of thermal capture gammas detected at the proximal and far detector) are determined and used to calculate the formation porosity. Techniques are disclosed for removing borehole and casing configuration effects from the measured proximal-to-far thermal capture ratio, leaving only porosity dependence.

A method and computing system device for receiving a plurality of well logs. A depth shift between at least one well log of the plurality of well logs and at least one other well log may be determined based upon, at least in part, processing the plurality of well logs with a neural network. The plurality of well logs may be matched with one another based upon, at least in part, the depth shift between the at least one well log and the at least one other well log.

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.

An x-ray based litho-density tool for measurement of formation surrounding a borehole is provided, the tool including at least an internal length comprising a sonde section, wherein said sonde section further comprises an x-ray source; at least one radiation measuring detector; at least one source monitoring detector; a plurality of sonde-dependent electronics; and a reference detector, wherein the reference detector is used to monitor the output of the x-ray source such that the reference detector's output effects corrections to the outputs of the detectors used to measure the density of the materials surrounding the borehole in order to correct for variations in the x-ray source output. Tool logic electronics, PSUs, and one or more detectors used to measure borehole standoff such that other detector responses may be compensated for tool standoff are also provided. Shielding, through-wiring, wear-pads that improve the efficacy and tool functionality are also described and claimed.

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.

Aspects of a method for mapping a perforation tunnel and crush zone of a perforated core sample. The method may include scanning a perforated core sample having a perforation tunnel containing a permeability-impairing material with a first computerized tomography (CT) scanning apparatus to produce a first 3D model of the perforation tunnel. The method may further include forming a cleared perforation tunnel by removing at least a portion of the permeability-impairing material from within the perforation tunnel without splitting the core sample at the perforation tunnel, and scanning the perforated core sample having the cleared perforation tunnel with a second computerized tomography (CT) scanning apparatus to produce a second 3D model of the cleared perforation tunnel. The method may compare the first 3D model and the second 3D model to obtain a 3D mapping of the perforation tunnel or a crush zone.