摘要:
A method for obtaining a parameter of interest related to an earth formation, the method including: obtaining nuclear magnetic resonance (NMR) data from an NMR tool investigating the earth formation with a plurality of pulse sequences of radio frequency energy, each pulse sequence having a unique frequency, a first train of pulses having a first interecho time (TE1) and a second train of pulses having a second interecho time (TE2) different from the first interecho time; relating the NMR data to a partial porosity at points to establish an NMR response model; solving the NMR response model to calculate the partial porosity at each of the points in the earth formation; summing the partial porosity for each of the points corresponding to each depth of investigation to provide a pore volume; and associating each pore volume with the corresponding depth of investigation to provide the parameter of interest.
摘要:
A method for obtaining a parameter of interest related to an earth formation, the method including: obtaining nuclear magnetic resonance (NMR) data from an NMR tool investigating the earth formation with a plurality of pulse sequences of radio frequency energy, each pulse sequence having a unique frequency, a first train of pulses having a first interecho time (TE1) and a second train of pulses having a second interecho time (TE2) different from the first interecho time; relating the NMR data to a partial porosity at points to establish an NMR response model; solving the NMR response model to calculate the partial porosity at each of the points in the earth formation; summing the partial porosity for each of the points corresponding to each depth of investigation to provide a pore volume; and associating each pore volume with the corresponding depth of investigation to provide the parameter of interest.
摘要:
A method for obtaining a parameter of interest relating to a region investigated by a nuclear magnetic resonance (NMR) tool and a non-NMR tool is disclosed. Data arising from the NMR tool is acquired, and data arising from the non-NMR tool is acquired. A solution equation is utilized for NMR signal intensity, the solution equation being functionally related to the NMR data, and a solution constraint is utilized based at least partially on the non-NMR data. The solution equation is solved for the signal intensity subject to the solution constraint, wherein the solving provides information relating to the parameter of interest.
摘要:
Formation testing systems and methods may inject fluids into a formation to initiate fractures and facilitate measurements of various formation properties. In accordance with certain disclosed embodiments, the injection tools are further provided with nuclear magnetic resonance (NMR) sensors to monitor the injected fluids and provide measurements of near-borehole fracture orientations and volumes. Contrast agents and/or magnetic resonance imaging (MRI) techniques may be employed. The fluid injection may occur via an extendible isolation pad, via a fracturing jet, or via an injection port in an isolated region of the borehole. The systems may employ pressure monitoring in conjunction with the NMR sensors to further enhance estimates of formation and fracture properties.
摘要:
An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus includes: a carrier configured to be conveyed through the borehole; a nuclear magnetic resonance (NMR) instrument disposed at the carrier and configured to perform an NMR measurement on a volume sensitive to the NMR measurement; and a contrast agent disposed in the volume and comprising particles that form a suspension in a liquid, the suspension of particles being configured increase a magnetic field gradient of at least one earth formation material in the volume to change an NMR relaxation time constant of the at least one earth formation material; wherein the NMR measurement on the volume containing the at least one earth formation material and the contrast agent is used to estimate the property.
摘要:
The grain size distribution of a pore-scale geometric model of a clastic earth formation are adjusted so that the NMR relaxation time distribution output of the model matches a measured NMR distribution, and an acoustic velocity output of the model matches a measured acoustic velocity (compressional and/or shear). Fluid drainage and imbibing can be simulated. Additional properties of the earth formation are predicted using the pore-scale model. The additional properties may be based on additional measurements of properties of a fluid in the formation.
摘要:
NMR porosity measurements made in a gas free-formation are used to calibrate acoustic measurements. The calibration parameters are then used in conjunction with estimates of shale content to provide improved estimates of formation porosity in shaly intervals which may include a gas.
摘要:
A method and apparatus for estimating a flow rate of a phase of a multiphase fluid is disclosed. In the first method, nuclei in the fluid are polarized over two distances and a measured magnetization gives the relative fraction of two components of the fluid for a selected velocity. In the second method, nuclei in the fluid are polarized over a specified distance and measurements of the decay of spin echo signals is used to give the relative fraction of two components of the fluid for the selected velocity.
摘要:
A method for analytically separating properties of hydrocarbon materials from other materials in a downhole environment, the method including: performing nuclear magnetic resonance (NMR) measurements downhole; determining a signal for sodium-23 (23Na) from the NMR measurements; and associating the 23Na signal with the other materials. A computer program product, an apparatus and additional methods are provided.
摘要:
Many reservoirs of interest include heavy oil. In such reservoirs, partly at normal temperatures, many instruments commonly used for formation evaluation may not be able to distinguish between heavy oil and bound water in the formation. Passive or active heating is used to elevate the temperature of the fluids in the formation. At elevated temperatures, distinguishing between heavy oil and bound water is easier. Of particular interest is the increase in the resolvability of the transverse relaxation time T2 of NMR spin echo measurements. Additionally, the dielectric constant and the loss tangents of water and heavy oil show different temperature and frequency dependence.