Abstract: A computer-implemented method for detecting artefacts in a medical image comprises obtaining input data associated with acquiring at least one image by a medical imaging system, applying a machine-learning model to the input data, whereby information about an image artefact in the image is determined, and providing the information about the image artefact, such as information about the presence and possible root-causes of the image artefact.

Abstract: The present invention provides a method for estimating hydrocarbon saturation of a hydrocarbon-bearing rock from a measurement for an electrical property a resistivity log and a rock image. The image is segmented to represent either a pore space or solid material in the rock. An image porosity is estimated from the segmented image, and a corrected porosity is determined to account for the sub-resolution porosity missing in the image of the rock. A corrected saturation exponent of the rock is determined from the image porosity and the corrected porosity and is used to estimate the hydrocarbon saturation. A backpropagation-enabled trained model can be used to segment the image. A backpropagation-enabled method can be used to estimate the hydrocarbon saturation using an image selected from a series of 2D projection images, 3D reconstructed images and combinations thereof.

Abstract: The present invention provides a method for estimating the permeability of rock from a digital image of the rock. A three-dimensional image of a rock is obtained and segmented, and an image permeability is determined from the segmented image of the rock. Permeability correction factors are obtained from the segmented image and from a non-wetting liquid capillary pressure curve derived from the segmented image, and the permeability correction parameters are applied to the image permeability to obtain a corrected image permeability of the rock.

Abstract: A method for calibrating a direct flow simulation of a rock sample involves providing a 3D image of a rock sample and generating a segmented structural image of the rock sample from the 3D image by selecting voxels to represent either a pore space or a solid material. Fluid flow is simulated on the segmented structural image with a direct flow simulation. A 3D spatially-resolved fluid velocity map is generated for one or more fluid phases at a pore-scale resolution using pulsed field gradient nuclear magnetic resonance imaging. The simulated fluid flow and the 3D spatially-resolved fluid velocity map are compared to calibrate the direct flow simulation across the rock sample.

Abstract: The present invention provides a method for estimating hydrocarbon saturation of a hydrocarbon-bearing rock from a measurement for an electrical property a resistivity log and a rock image. The image is segmented to represent either a pore space or solid material in the rock. An image porosity is estimated from the segmented image, and a corrected porosity is determined to account for the sub-resolution porosity missing in the image of the rock. A corrected saturation exponent of the rock is determined from the image porosity and the corrected porosity and is used to estimate the hydrocarbon saturation. A backpropagation-enabled trained model can be used to segment the image. A backpropagation-enabled method can be used to estimate the hydrocarbon saturation using an image selected from a series of 2D projection images, 3D reconstructed images and combinations thereof.

Abstract: The present invention provides a method for estimating hydrocarbon saturation of a hydrocarbon-bearing rock from a resistivity log and a rock image. The image is segmented to represent either a pore space or solid material in the rock. An image porosity is estimated from the segmented image, and a corrected porosity is determined to account for the sub-resolution porosity missing in the image of the rock. A corrected cementation exponent of the rock is determined from the image porosity and the corrected porosity and is used to estimate the hydrocarbon saturation. A backpropagation-enabled trained model can be used to segment the image. A backpropagation-enabled method can be used to estimate the hydrocarbon saturation using an image selected from a series of 2D projection images, 3D reconstructed images and combinations thereof.

Abstract: The present invention provides a method for estimating the permeability of rock from a digital image of the rock. A three-dimensional image of a rock is obtained and segmented, and an image permeability is determined from the segmented image of the rock. Permeability correction factors are obtained from the segmented image and from a non-wetting liquid capillary pressure curve derived from the segmented image, and the permeability correction parameters are applied to the image permeability to obtain a corrected image permeability of the rock.

Abstract: The present invention provides a method for determining the porosity of rock from a digital image of the rock. A three-dimensional image of a rock is obtained and segmented, and an image porosity is determined from the segmented image of the rock. A porosity correction parameter is obtained from a non-wetting liquid capillary pressure curve derived from the segmented image, and the porosity correction parameter is applied to the image porosity to obtain a corrected porosity of the rock.

Abstract: The present invention provides a method for determining the porosity of rock from a digital image of the rock. A three-dimensional image of a rock is obtained and segmented, and an image porosity is determined from the segmented image of the rock. A porosity correction parameter is obtained from a non-wetting liquid capillary pressure curve derived from the segmented image, and the porosity correction parameter is applied to the image porosity to obtain a corrected porosity of the rock.

Abstract: An imager and method for imaging fluid of a subsurface formation is disclosed. The imager includes a housing having a sidewall defining a passage to receive a core sample of the subsurface formation therethrough. The housing is positioned in a downhole tool and has a fluid inlet to receive fluid from the subsurface formation into the passage. The imager also includes a permanent magnet positioned in the sidewall of the housing, a radio frequency coil positioned in the sidewall of the housing between the permanent magnet and the passage, a gradient field in the sidewall of the housing between the permanent magnet and the radio frequency coil, and a chemically-selective imager. The chemically-selective imager is operatively connected to the radio frequency coil to selectively pulse frequencies according to a pulse sequence whereby individual fluid measurements of the sample are generated.

Abstract: A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2) having a magnetic field generator (4), a measuring unit (5) and an antennae unit (6) with an antenna (7). wherein the antennae unit (6) has at least one further antenna (11, 12), that is designed as a coil and is designed for transmitting the excitation signal to the magnetized medium (3) and for detecting the measuring signal over a further measuring section (13, 14) aligned parallel to the longitudinal axis (8) of the measuring tube and located in the magnetic field path (9), and the measuring section (10) and the further measuring section (13, 14) are different.

Abstract: A gamma ray scintillation spectrometer is disclosed in which an inorganic scintillation crystal has a channel extending therethrough for receiving a sample into, and disposing a sample out of, the scintillation crystal. The spectrometer further includes a photomultiplier tube optically coupled to the scintillation crystal to detect photons generated by the scintillation crystal. A system and a method for using the gamma ray scintillation spectrometer are also provided.

Abstract: A gamma ray scintillation spectrometer is disclosed in which an inorganic scintillation crystal has a channel extending therethrough for receiving a sample into, and disposing a sample out of, the scintillation crystal. The spectrometer further includes a photomultiplier tube optically coupled to the scintillation crystal to detect photons generated by the scintillation crystal. A system and a method for using the gamma ray scintillation spectrometer are also provided.

Abstract: A method for assessing a gas phase in a flowing multi-phase fluid comprises flowing the fluid through magnetic resonance and pre-polarization modules and applying to the fluid a radio-frequency pulse sequence at least once with and at least once without a magnetic field gradient. The method further includes measuring an NMR signal. The method also includes using a calibration between the ratio of slope and intercept of the NMR signal and flow velocity for at least one non-gas phase with the gradient applied to determine that phase's velocity. A calibration between the signal intensity of the liquid phases as function of flow velocity is used, with and without gradient, to correct the gradient-induced attenuation of the liquid signals and to calculate a gradient-corrected signal intensity of the liquid phases without a magnetic field gradient. Additionally, the method includes subtracting the gradient-corrected signal intensity from the NMR signal to calculate the volumetric fraction of the liquid phase.

Abstract: An imager and method for imaging fluid of a subsurface formation is disclosed. The imager includes a housing having a sidewall defining a passage to receive a core sample of the subsurface formation therethrough. The housing is positioned in a downhole tool and has a fluid inlet to receive fluid from the subsurface formation into the passage. The imager also includes a permanent magnet positioned in the sidewall of the housing, a radio frequency coil positioned in the sidewall of the housing between the permanent magnet and the passage, a gradient field in the sidewall of the housing between the permanent magnet and the radio frequency coil, and a chemically-selective imager. The chemically-selective imager is operatively connected to the radio frequency coil to selectively pulse frequencies according to a pulse sequence whereby individual fluid measurements of the sample are generated.

Abstract: A method for assessing a gas phase in a flowing multi-phase fluid comprises flowing the fluid through magnetic resonance and pre-polarization modules and applying to the fluid a radio-frequency pulse sequence at least once with and at least once without a magnetic field gradient. The method further includes measuring an NMR signal. The method also includes using a calibration between the ratio of slope and intercept of the NMR signal and flow velocity for at least one non-gas phase with the gradient applied to determine that phase's velocity. A calibration between the signal intensity of the liquid phases as function of flow velocity is used, with and without gradient, to correct the gradient-induced attenuation of the liquid signals and to calculate a gradient-corrected signal intensity of the liquid phases without a magnetic field gradient. Additionally, the method includes subtracting the gradient-corrected signal intensity from the NMR signal to calculate the volumetric fraction of the liquid phase.

Abstract: A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2) having a magnetic field generator (4), a measuring unit (5) and an antennae unit (6) with an antenna (7). wherein the antennae unit (6) has at least one further antenna (11, 12), that is designed as a coil and is designed for transmitting the excitation signal to the magnetized medium (3) and for detecting the measuring signal over a further measuring section (13, 14) aligned parallel to the longitudinal axis (8) of the measuring tube and located in the magnetic field path (9), and the measuring section (10) and the further measuring section (13, 14) are different.

Abstract: A magnetic resonance based apparatus capable of measuring, without using time-of-flight measurements, flow regimes of multi-phase fluids in a pipe, comprises a magnetic resonance module through which the fluid phases flow, wherein the magnetic resonance module includes a radiofrequency coil for transmitting and detecting a signal and means for generating inside the module a homogenous constant magnetic field Bx that is thermally compensated and a transverse magnetic field gradient Gx that is superposed on Bx; and at least one pre-polarization module through which the fluid phases flow before entering the magnetic resonance module.

Abstract: A system for producing oil and/or gas from an underground formation comprising a well above the formation; a mechanism to inject an enhanced oil recovery formulation into the formation, the enhanced oil recovery formulation comprising water and an additive; and a mechanism to produce oil and/or gas from the formation.

Abstract: A magnetic resonance based apparatus capable of measuring, without using time-of-flight measurements, flow regimes of multi-phase fluids in a pipe, comprises a magnetic resonance module through which the fluid phases flow, wherein the magnetic resonance module includes a radiofrequency coil for transmitting and detecting a signal and means for generating inside the module a homogenous constant magnetic field Bx that is thermally compensated and a transverse magnetic field gradient Gx that is superposed on Bx; and at least one pre-polarization module through which the fluid phases flow before entering the magnetic resonance module