Abstract: The method includes gathering field data of a formation, preparing samples of brine consistent with the composition of the formation brine and the injection brine, dead crude oil, and live crude oil, and characterizing the properties of crude oil samples. The method includes preparing samples of reservoir rock and characterizing the properties of the rock samples of the formation. The method includes measuring the contact angle of surfactant/formation brine/formation rock/formation crude oil samples at ambient and reservoir conditions and measuring the interfacial tension of the sample. The method includes characterizing the HLD properties of each surfactant. In addition, the method includes performing formulation targeting HLD=0 for a mixture of surfactants, performing laboratory evaluation of the HLD=0 formulation of the mixture of the surfactants to obtain values of oil recovery number, and testing the HLD=0 formulation of the mixture of the first and second selected surfactants in the formation.

Abstract: The present invention discloses a gas based testing method for a pore volume compressibility of a low-permeability rock. The method comprises the following steps: obtaining a compressibility and an isothermal adsorption-desorption curve of experimental gas under a reservoir condition; performing a physical simulation experiment by using a steel core drilled with a through hole, and obtaining a gas volume collected due to the deformation of an experimental instrument; then repeating the experiment by using an actual core with the same size, and obtaining pore volumes of the reservoir core under the experimental conditions by deducting deformation of the instrument; and finally, obtaining a pore compressibility of the reservoir core under different reservoir conditions according to the pore volumes of the reservoir core under different reservoir conditions. The present invention considers gas adsorption, corrects errors caused by deformation of a physical simulation device.

Abstract: A lost circulation material is placed in a cavity. The cavity is defined by an inner bore of a cylindrical wall, intermediate of a piston and a screen. A distance between the piston and the screen is defined as the height of the cavity, which is adjustable. The piston is slid longitudinally, such that the piston comes in contact with the lost circulation material. The lost circulation material is heated to a specified test temperature mimicking a downhole temperature. A compression test is performed on the lost circulation material. The compression test includes flowing a test fluid into the cavity and applying force on the piston to pressurize the test fluid to a specified test pressure mimicking a downhole pressure. The force on the piston is released. The pressure of the test fluid and the height of the cavity are measured throughout the compression test.

Abstract: Systems and methods presented herein provide for the generation of acoustic waves for acoustic stimulation, as well as for analysis of subterranean formations, using downhole tools and associated equipment that are not conventionally designed to do so. For example, in certain embodiments, formation testing tools, formation, measurement tools, inflatable packers, and so forth, may be controlled by control systems to, for example, create pressure pulses that generate the acoustic waves. In addition, in certain embodiments, a tool conveyance system that conveys a formation testing or measurement tool into a wellbore may include acoustic receivers that may detect the acoustic waves after they reflect from subterranean features of the formation.

Abstract: A high pressure core chamber for use in collecting pressurized core samples from a reservoir is equipped with at least two high pressure access valves, allowing the core chamber to also function as a vessel for various high pressure experiments. In some embodiments, the core chamber is also equipped with a heater, allowing high pressure, high temperature experiments, and thus duplicating reservoir conditions. Various assays using the core chamber are also described.

Abstract: Autonomous wireless sensors in subsurface environments can be charged while present in the subsurface environment to allow the sensors to measure and wirelessly transmit measurements. The sensors rely upon a contrast agent to provide a power flow path to the sensors.

Abstract: A method and system for performing a pressure test. The method may include inserting a formation testing tool into a wellbore to a first location within the wellbore based at least in part on a figure of merit. The formation testing tool may include at least one probe, a pump disposed within the formation testing tool and connect to the at least one probe by at least one probe channel and at least one fluid passageway, and at least one stabilizer disposed on the formation testing tool. The method may further include activating the at least one stabilizer, wherein the at least one stabilizer is activated into a surface of the wellbore and performing the pressure test and determining at least one formation property from the pressure test.

Abstract: A system that monitors toilets for leaks using in-toilet monitors with pressure sensors that are placed underwater in toilet tanks. Monitors can be dropped into tanks without additional wiring or installation; they may be battery powered and may transmit data wirelessly. Data may be analyzed by a server that detects leaks or other malfunctions. Pressure data may be filtered to remove the effect of barometric pressure, to measure the height of water in the tank. The system may learn the flush pressure change pattern for each toilet; pressure changes that do not match this pattern may indicate problems such as leaks. Data may indicate the type of leak, such as an open flapper or a leaking valve. Toilet monitors may measure temperature, and the system may generate alerts when freezing appears imminent. The system may keep flush counts for each toilet to support maintenance and water consumption measurement.

Abstract: Techniques for determining grain density of a rock sample include identifying an untreated rock sample that includes a solid matrix and a fluid entrained within the solid matrix; measuring, using a gas porosimeter, a grain density of the untreated rock sample; measuring, using nuclear magnetic resonance (NMR), a volume of the fluid entrained within the solid matrix; and determining, based on the measured grain density of the untreated rock sample and the measured volume of the fluid, a grain density of the solid matrix of the untreated rock sample.

Abstract: A method to manipulate a well comprising providing an apparatus (60) in a well (14) below a packer (22) or other annular sealing device, the apparatus comprising a container (68) having a volume of gas which is sealed at the surface and nm into the well, such that the pressure in the container (68) is at a lower pressure than the surrounding well. When the apparatus is below the packer, a wireless control signal, is sent to operate a valve assembly (62) to selectively allow fluid to enter the container whereby at least 50 litres of fluid is drawn into the container. In this way, the apparatus can be used independent of perforating guns, to clear perforations or other areas in the well or may be used for a variety of tests such as an interval test, drawdown test or a connectivity test such as a pulse or interference test.

Abstract: Methods may include creating a fracture set from a collection of intersecting fractures in a borehole image log recorded within a subterranean formation; classifying the fracture set into groups of fully and partially intersecting fractures; calculating one or more of the elongation ratio and the rotation angle of the partially intersecting fractures; determining a probability of full intersection of fractures from the fracture set; and determining a fracture size or a parametric distribution of fracture sizes from the fracture set using the calculated one or more of the elongation ratio and the rotation angle and the determined probability of full intersection of formation fractures within the borehole.

Abstract: A method for measuring a fracture permeability and a matrix permeability of a naturally fractured cylindrical rock sample, includes sealing both flat ends of the cylindrical sample; immersing the naturally fractured cylindrical rock sample in a fluid, and attaching an axial and a radial strain sensor to the curved surface of the sample. Furthermore, the method includes attaching a signal generator to one flat end of sample, and a signal receiver to the other flat end of the sample, and generating a harmonic excitation using the signal generator at a plurality of frequencies and recording the excitation at each of the plurality of frequencies. The method includes calculating an elastic wave propagation attribute at each of the plurality of frequencies, and inverting the elastic wave propagation attribute at each of the plurality of frequencies to determine the fracture permeability and the matrix permeability of the naturally fractured cylindrical rock sample.

Abstract: Methods and systems for controlling drilling operations are described. The methods include conveying a drilling tool from the earth surface into a wellbore and operating the drilling tool to drill in a drilling direction, wherein drilling mud is conveyed from the earth surface to the drilling tool and returned to the earth surface, obtaining gas data from the drilling mud that returns to the earth surface, determining a reservoir property from the gas data, and adjusting the drilling direction based on the determined reservoir property.

Abstract: A method, system and computer program product for determining soil properties comprising a probe including at least a liquid injection port and a pressure transducer. The probe is pushed into a soil and one or more pumping tests are carried out, wherein during a pumping test infiltration liquid is pumped through the liquid injection port of the probe. The pressure response in the soil resulting from the injection of liquid through the liquid injection port is measured for each of the one or more pumping tests.

Abstract: Embodiments include systems and methods for determining properties of a formation including disposing a core sample of the formation within a core holder assembly, applying pressures to the core sample, rotating the core sample about a center longitudinal axis of the core holder assembly, obtaining a series of computed tomography images of the core sample at different rotation increments of the core sample, generating, based at least partially on the obtained series of computed tomography images of the core sample, a 3D representation of the core sample utilizing a radon transform, measuring a displacement of at least one characteristic of the core sample due to the applied pressures, and based at least partially on the measured displacement, determining at least one property of the formation as a function of the applied pressures.

Abstract: Device and method for measuring two-phase relative permeability curve of unconventional oil reservoir are provided, wherein the device comprises: two-dimensional porous seepage microscopic model; injection components connected to inlet end of the two-dimensional porous seepage microscopic model; confining pressure components arranged outside the two-dimensional porous seepage microscopic model; a camera component arranged on one side of the two-dimensional porous seepage microscopic model; back pressure components connected to outlet end of the two-dimensional porous seepage microscopic model; and outlet pressure measuring and recovery components connected to outlet end of the two-dimensional porous seepage microscopic model. Two-phase relative permeability curve of unconventional oil reservoir can be measured accurately through the device.

Abstract: The invention provides a physical simulation experimental device and method for water invasion and drainage gas recovery in gas reservoir, and the experimental device includes: a heterogeneous reservoir model having a first core holder, a second core holder, a third core holder and a fourth core holder, wherein the third core holder is connected between the first core holder and the second core holder, and the fourth core holder is connected between an outlet end of the first core holder and an outlet end of the second core holder; a gas injection mechanism having a gas injection bottle and a gas injection cylinder; a water body simulation mechanism having a water storage tank and a water injection pump. The invention can simulate and reveal different drainage gas recovery modes, timings, scales and their influences on the recovery ratio of the gas reservoir.

Abstract: A method for characterizing a sand-pack or gravel-pack in a subsurface formation includes inducing a pressure change to induce tube waves in fluid in a well drilled through the subsurface formation. At a location proximate to a wellhead at least one of pressure and a time derivative of pressure in the well is measured for a selected length of time. At least one of a physical parameter and a change in the physical parameter with respect to time, of the sand-pack or gravel-pack, is determined using the measured pressure and/or the time derivative of pressure.

Abstract: Apparatus and methods for obtaining initial settings of station-specific parameters descriptive of wellbore/formation properties specific to downhole pressure test stations, and obtaining initial settings of station-shared parameters descriptive of petrophysical properties of petrophysically unique formation zones. A pressure transient model of the zones is obtained by regression utilizing the pressure data of each station and the initial settings of the station-specific and station-shared parameters. The regression analytically determines a model value of at least one of the station-specific parameters and the station-shared parameters.

Abstract: An apparatus for testing lost circulation materials (“LCMs”) for use in a formation is disclosed. The apparatus may comprise a LCM cell that contains at least one formation simulation component. A pressurized tank may be in fluid communication with the LCM cell, and may force a sample LCM slurry into the LCM cell. An LCM receiver may also be in fluid communication with the LCM cell, and may receive the LCM slurry that flows through the LCM cell.

Abstract: The method for determining equilibrium wettability of an interface between a void space and a solid phase of a rock sample comprises obtaining a three-dimensional image of the internal structure of the sample. On the obtained image of the internal structure of the sample, a void space and a solid phase are differentiated. An interface between the void space and the solid phase of the sample and distribution of minerals on this surface are determined. Wettability of the solid phase at each point of the interface between the void space and the solid phase of the rock sample is determined. A process of oil migration to the void space filled with stratum water at the initial stage of formation of an oil and gas field is numerically simulated, and finally, the equilibrium wettability of the interface between the void space and the solid phase of the rock sample is determined.

Abstract: A non-transitory computer-readable medium includes computer-executable instructions for presenting dumpflood data to a user by implementing steps on a computer. The steps include: receiving first data describing a first subsurface volume; receiving second data describing a second subsurface volume that is deeper than the first subsurface volume; calculating pressures required for a fluid to flow in a borehole from the first volume to the second volume as a function of vertical height of the first volume (h1), permeability of the first volume (k1), vertical height of the second volume (h2), permeability of the second volume (k2), a first damage factor (S1) representing damage to the first volume, and a second damage factor (S2) representing damage to the second volume; and displaying on a computer display a graphical representation of the calculated pressures and inputs used to calculate the pressures.

Abstract: Techniques involve obtaining dielectric measurements measured from a dielectric logging tool investigating a borehole at a one or more frequencies in a first frequency range, obtaining inductive measurements measured from an inductive tool investigating the borehole at one or more frequencies in a second frequency range, where the second frequency range is higher than the first frequency range, estimating an estimated resistivity anisotropy by conducting an inversion on the dielectric measurements, computing a measured resistivity anisotropy by conducting an inversion on the inductive measurements, and determining a characteristic related to reservoir fluids in the borehole, based on a comparison of the estimated resistivity anisotropy and the measured resistivity anisotropy.

Abstract: Various embodiments include apparatus and methods to estimate formation mobility from Stoneley waveforms. An objective function can be generated that represents misfit between measured Stoneley pressure values and synthetic pressure values. A minimization process can be applied to the objective function to estimate formation mobility and intrinsic attenuation. Additional apparatus, systems, and methods are disclosed.

Abstract: The disclosure provides a kick detection system for use during a drilling operation where wellbore kick warnings are provided based on indications of standoff conditions in a compensated instrument system. The system provides a warning of a potential kick condition by analyzing a current instrument compensation against a time series of past compensations, in order to monitor whether conditions within the standoff region of the wellbore are unexpectedly changing. The system comprises a source, a short-spaced detector, and a long-spaced detector, and a processor receives the short-spaced signal and the long-spaced signal, compensates the long-spaced signal, and generates standoff data reflecting the corrections applied to the long-range signal. The processor determines and maintains the standoff data as a time series and periodically compares a recent data point to a moving average in order to evaluate indications of a potential well kick.

Abstract: An apparatus for testing lost circulation materials (“LCMs”) for use in a formation is disclosed. The apparatus may comprise a LCM cell that contains at least one formation simulation component. A pressurized tank may be in fluid communication with the LCM cell, and may force a sample LCM slurry into the LCM cell. An LCM receiver may also be in fluid communication with the LCM cell, and may receive the LCM slurry that flows through the LCM cell.

Abstract: System and method for monitoring frac fluid flow through a column bed includes preparing a vessel (112, 440) with a column including a filtering member (120, 420), a column bed (114, 414) simulating a downhole environment, and a frac fluid (116, 416). Frac fluid (116, 416) is flowed through the column bed (114, 414) at an acceleration exceeding gravity for a predetermined period of time. The amount of liquid that flows through the column bed (114, 414) and that is recovered after the predetermined period of time is then determined.

Abstract: In one aspect, a method of obtaining a fluid from a formation is disclosed that in one embodiment may include: pumping fluid received by a first probe from the formation into the wellbore; pumping fluid received by a second probe from the formation into the wellbore; determining when the fluid received by one of the first and second probes is clean; and pumping the fluid received by the first probe into a sample chamber while collecting the formation fluid received by the second probe from the formation into a storage chamber having an internal pressure less than the pressure of the formation.

Abstract: A apparatus for measuring saturated hydraulic conductivity of unsaturated porous media in an unsaturated zone of the earth. The measuring apparatus includes a cylinder member inserted into the porous media in a position in which the upper and lower ends of the cylinder member are open, a means for supplying a constant flow rate of water to the cylinder member, and a pressure measuring means for measuring the hydraulic head in response to water flowing into the cylinder member. The measuring apparatus can easily measure the vertical hydraulic conductivity of a foundation based on Darcy's Law in the field. It is possible to accurately measure the hydraulic conductivity of a sedimentary layer in the natural state and easily determine geological characteristics of the soil. It is possible to obtain very accurate information regarding the process of dispersion and movement of contaminants.

Abstract: There is provided a water exchange meter being capable of automatically and continuously measuring the water exchange at the surface water/sediment interface in which a saturated vertical hydraulic conductivity of the sediment from the hydraulic head difference between a chamber and a storage pipe at a measurement location is measured, and after the measurement of the saturated vertical hydraulic conductivity, while the measurement device used in the measurement of the vertical hydraulic conductivity is maintained, a vertical hydraulic gradient between upper and lower portions of a chamber is continuously measured in situ.

Abstract: A remotely operated lifting top drive cement head is provided having a high tensile strength, as well as the ability to swivel or rotate about a central vertical axis. The cement head permits selective launching of darts, setting plugs, balls or other objects which can be held in place within the cement head without being damaged or washed away by slurry flow, but which can be beneficially launched into said slurry flow at desired point(s) during the cementing process. The internal components of the cement head can be easily accessed using interrupted thread connections that can be quickly and easy connected and disconnected in the field without requiring specialized equipment. The cement head can be rigged up and remotely operated without requiring the lifting of personnel off the rig floor to actuate the tool or observe tool status.

Abstract: A mud sensing hole finder comprising: a front steering wheel assembly, a rear wheel assembly, a sensor package, a corrosion package, a ported housing, and a tapered spring joint; wherein the mud sensing hole finder is capable of attachment to a wireline logging tool-string.

Abstract: A method of estimating a geology of an earth formation includes: receiving gravity measurements from each of a plurality of gravity sensors nsj arrayed along a length of a borehole in an earth formation, each of the sensors nsj generating a gravity measurement gj associated with a location zsj, each of the plurality of sensors separated by a distance h; generating a model of the earth formation that includes approximate geological boundaries Nm having an approximate depth zmk, the geological boundaries defining a number of geologic layers therebetween; assuming that each geological boundary is represented by a minimum density change and each of the geologic layers has a thickness that encompasses two or more of the plurality of sensors nsj; and estimating a location and a density change ?? of a geologic boundary z between locations zsj and zsj+1 based on the gravity measurements gj and the distance h.

Abstract: Borehole conditions can be determined using distributed measurement data. Real time data measurements can be taken from sensors distributed along the length of a drill string to assess various conditions or properties of the borehole. In particular, the distributed data can be used for example, to track the progress of a chemical pill or also track the location of different types of borehole fluids, and also to determine the hole size or volume of the borehole.

Abstract: A method and apparatus for performing water based mud-filtrate contamination monitoring in real time through evaluation of downhole water sampling.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to receive a vibration signal having a frequency and a characteristic (e.g., voltage) proportional to the vibration amplitude of a tube in a vibrating tube density sensor. Further activity may include transmitting the density of a fluid flowing through the tube based on the frequency and an elastic modulus of the tube determined by the value of the characteristic. Additional apparatus, systems, and methods are described.

Abstract: A method including positioning a formation testing tool within a wellbore formed within a subsurface reservoir, wherein the tool has a focused opening to enable fluid communication with the reservoir, and the tool has a horizontally-displaced observation probe configured to obtain pressure data; determining one of horizontal permeability and horizontal mobility of the reservoir based on measuring a flow response of the subsurface reservoir one of at and adjacent to the observation probe; and determining orthogonal components of one of the horizontal permeability and horizontal mobility based on the measured flow response.

Abstract: Systems and methods for gas sorption analysis, or analogous practices, of samples from unconventional reservoirs are described. The described analysis of samples is used to determine various properties of unconventional reservoirs, which are used in evaluating their worth and producibility.

Abstract: A method for determining a characteristic of an underground formation with a fluid is described. The method includes providing a sample material of the underground formation; measuring the permeability and the porosity of the sample material; performing a drainage test on the sample material using the fluid; estimating the threshold pressure of the sample material from the drainage test, the permeability and the porosity measurements; and determining the receding contact angle of the fluid on the sample material from the threshold pressure. The sample material can be disaggregated material.

Abstract: A method for determining the frequency-dependent dielectric permittivity spectrum of a rock sample, comprising:—defining a series of electromagnetic measurement data comprising at least a first measurement at a frequency from which a substantially frequency-independent value of dielectric permittivity ??, can be obtained; and at least second and third measurements at different frequencies from which values for frequency-dependent dielectric permittivity ?rock (f) can be obtained; and—using the first, second and third measurements to determine the frequency-dependent spectrum of the sample.

Abstract: Methods for deriving relative permeability from resistivity measurements in the laboratory and from downhole resistivity measurements are described. Further, systems and methods for determining relative permeability from borehole resistivity measurements made during a water flooding event such as drilling with water-based mud, water injection and/or water invasion are described.

Abstract: A method and apparatus is provided for off-line concentration determination of components liquid hydrocarbon mixtures such as crude or heavy oil. A sampling unit continuously delivers a sample volume to a fluid flow path while a temperature control module maintains the sample at a predetermined setpoint temperature. A homogenization module helps prevent sample stratification while a flow control module maintain a constant sample flow rate. A spectrometer is communicably coupled to an optical transmission cell to transmit and receive radiation. The transmission cell includes collection optics to capture and aggregate non-collimated radiation emerging from the cell, for transmission to the spectrometer. The spectrometer measures sample spectra at a predetermined rate of flow of the sample volume through the transmission cell. A processor is configured to capture and use the spectra in combination with a model of spectra for the hydrocarbon mixture.

Abstract: A method for detection of permeability anisotropy, having steps of positioning a formation testing tool, conducting a series of three flow tests with the testing tool wherein a first test is a four drain flow test, a second test is a pair of opposite drains flowing on diametrically opposite sides of the formation testing tool and a third test is a second pair of opposite drains flowing on opposite drains different than the second test; determining one of horizontal permeability and horizontal mobility, determining one of orthogonal components of horizontal permeability and horizontal mobility based on the measured flow response and determining a direction of the orthogonal components of the horizontal permeability or horizontal mobility with respect to the orientation of the formation testing tool based on a measured flow response.

Abstract: A bottomhole assembly is provided with a cathode. The cathode produces a static field in the earth formation and by the electroosmotic effect, inhibits the invasion of the formation by borehole fluids and reduces formation damage. The cathode also results in improved estimates of formation permeability using flow tests. A cathode on a wireline string may be used to reduce water saturation in an invaded zone near a borehole.

Abstract: An apparatus and method used to determine the density and other properties of a corrosive liquid, such as drilling mud. The apparatus uses at least two sensor elements with ceramic facings spaced a known vertical distance apart and inserted into the fluid. The differential pressure measurement provided by these sensors is used to calculate the density of the liquid. This density measurement is then reported in real-time to an operator.

Abstract: An apparatus for measuring permittivity of a sample. The apparatus includes: a sample chamber including a sealed space portion in which a sample to be measured is put; a pressure adjusting unit for varying pressure by applying water pressure to the space portion of the sample chamber; a permittivity sensor for measuring permittivity of the sample and disposed outside the sample chamber; measurement conducting wires including conductors, installed to contact the sample and connected to the permittivity sensor by using electric wires; and a data logger for storing data relating to permittivity that is measured by the permittivity sensor.

Abstract: According to aspects of the present disclosure, an apparatus for testing lost circulation materials (LCMs) within a permeability plugging apparatus (PPA) is described. The apparatus may include a PPA cell cap and an elongated LCM receiver. At least one tubular member may provide fluid communication between the PPA cell cap and the elongated LCM receiver. The at least one tubular member may be sized to accommodate large particulate LCM testing within the PPA. The apparatus may also include a backpressure inlet through the elongated LCM receiver. Providing back pressure within the LCM receiver may extend the temperature and pressure ranges under which the large particulate LCMs may be tested.

Abstract: An apparatus and method for simulating production conditions in hydrocarbon-bearing reservoirs, as an example, by flooding of core samples from such reservoirs, are described. Full recirculation flow measurements permit several fluids (for example, crude oil, brine, and gas) to be simultaneously injected into core samples having varying dimensions. Accurate and stable back pressures are maintained at total flow rates of as high as 200 cc/min., for a large range of fluid viscosities. Accurate and stable net overburden pressures relative to pore pressure are also maintained, thereby simulating the formations at depth. Core samples from formations may also be investigated using the apparatus and method hereof, for carbon dioxide sequestration potential, as another example.

Abstract: Disclosed is a method of reducing uncertainty, which exactly finds the hydraulic conductivity and the specific storativity of a rock sample in pressure pulse-decay measurement. Axial and confining pressures are applied to the rock sample, and upstream and downstream reservoirs are connected to the rock sample. Coordinate values representing minimum values of a contour of a graph of an objective function, in which the hydraulic conductivity and the specific storativity obtained through the pressure pulse-decay measurement scheme to apply pressure pulses from the outside are expressed in horizontal and vertical axes are found from the graph. The coordinate values are set as the hydraulic conductivity and the specific storativity of the rock sample. Graphs of objective functions obtained by repeating the pressure pulse-decay measurement while changing boundary conditions are shown in overlapped, thereby reducing the uncertainty of the hydraulic conductivity and the specific storativity of the rock sample.

Abstract: Systems and methods that provide relaxivity-insensitive permeability logs. At least some logging system embodiments include a logging tool assembly that measures spin-spin relaxation time distributions of formation fluid nuclei at different positions along a borehole. A processor operates on the measurements to provide a permeability log that is relatively insensitive to relaxivity coefficient changes and hence insensitive to changes in formation fluids. Thus, permeability logs will be relatively unaffected by invasion of the borehole fluids into the formation, even if surfactants in the borehole fluid cause large changes in formation wettability. For each position logged within a borehole, the processor may process the measured relaxation time distribution to determine a Swanson parameter value; adjust the Swanson parameter value to reduce dependence on relaxivity; and convert the adjusted value to a permeability measurement.