摘要:
A method of estimating properties of a resource bearing formation includes receiving, by a processor, a measured echo train generated by a nuclear magnetic resonance (NMR) measurement device deployed in a region of interest, and a measured noise of the measured echo train, and calculating a T2 distribution subject to a nonlinear equality constraint, the nonlinear equality constraint dependent on the measured noise and a fitting error between the measured echo train and a modeled echo train. Calculating the T2 distribution includes estimating a solution for the T2 distribution that is closest to satisfying the nonlinear equality constraint.
摘要:
A method of estimating properties of a resource bearing formation includes receiving, by a processor, a measured echo train generated by a nuclear magnetic resonance (NMR) measurement device deployed in a region of interest, and a measured noise of the measured echo train, and calculating a T2 distribution subject to a nonlinear equality constraint, the nonlinear equality constraint dependent on the measured noise and a fitting error between the measured echo train and a modeled echo train. Calculating the T2 distribution includes estimating a solution for the T2 distribution that is closest to satisfying the nonlinear equality constraint.
摘要:
A method of estimating a wettability characteristic of a rock material includes acquiring a plurality of T2 distributions based on nuclear magnetic resonance (NMR) measurements of a rock material under a plurality of fluid saturated rock conditions, constructing a measurement matrix based on the plurality of T2 distributions, and performing non-negative factorization of the measurement matrix to determine feature components. The method also includes reconstructing the plurality of T2 distributions based on the feature components, and extracting a first set of T2 distributions associated with mobile water under a wetting condition and a second set of T2 distributions associated with mobile water under a non-wetting condition based on the feature components, and calculating a wettability index (WI) based on the first extracted set of T2 distributions and the second extracted set of T2 distributions.
摘要:
A method for transforming an earth formation and/or production equipment based on correcting nuclear magnetic resonance (NMR) data to account for partially water-saturated rock includes: receiving NMR logging data having echo-trains for an earth formation; inverting the echo-trains to provide transverse relaxation time constant (T2) distributions for various components of fluid in the earth formation; substituting a T2 distribution for mobile water of fully water-saturated rock for a T2 distribution for mobile water of partially water-saturated rock based on values of the mobile water T2 distribution of partially water-saturated rock and a total porosity constraint; summing the T2 distribution for mobile water of fully water-saturated rock and a T2 distribution for an immobile water component of the fluid to provide a T2, distribution for fully water-saturated rock; and transforming the earth formation and/or the production equipment based on a parameter derived from the T2 distribution for fully water-saturated rock.
摘要:
An apparatus for use in a wellbore may include a tool having a first section configured to receive a core and a second section configured to collect a gas escaping from the core. The apparatus may also include a sensor associated to provide signals relating to a property of gas. In one aspect, the second section may be removable and may be pressurized. The apparatus may also include a recorder that records data representative of the signals received from the sensor. The recorder may record data while the tool is retrieved from the wellbore. A method for estimating a parameter of interest of a formation includes retrieving a core from the formation, collecting a gas escaping from the core as the core is retrieved to the surface, and measuring at least one property of gas while the core is retrieved to the surface.
摘要:
A method for characterizing a bond between a first tubular disposed in a borehole and a structure outside of the tubular, the method includes transmitting a signal into and through the first tubular using a signal transmitter conveyed through the borehole and detecting a return signal using a return signal receiver conveyed through the borehole to provide return signal information in a time domain. The method also includes transforming the return signal information in the time domain to return signal information in a frequency domain using a transform and determining a difference between the return signal information in the frequency domain and reference frequency domain return signal information. The method further includes characterizing the bond of the first tubular to the structure outside of the first tubular using the difference to provide a characterization of the bond.
摘要:
Gas from a tight gas formation may be produced using a drain hole having a juncture to a main wellbore and a terminal end at a depth higher than the juncture. The terminal end may be positioned in the tight gas formation.
摘要:
Methods for determining properties of a media on an exterior of a casing in downhole systems are described. The methods include conveying a logging tool through a casing in a downhole formation, stimulating shear waves and flexural waves in the casing, obtaining a shear attenuation rate measurement and a flexural attenuation rate measurement within the casing responsive to the media on the exterior of the casing, comparing the measured shear attenuation rate and the measured flexural attenuation rate against a plurality of respective division boundary values, and determining one or more properties of the media on the exterior of the casing based on the comparison of the measured shear attenuation rate and the measured flexural attenuation rate against the plurality of respective interfaces.
摘要:
A method for estimating an amount of hydrocarbon in an earth formation having a kerogen includes determining a pore size in the kerogen at or below which capillary condensation will occur, the determining being performed using a processor. The method also includes calculating an amount of hydrocarbon liquid condensate in pores of the kerogen based on capillary condensation using the determined pore size, the calculating being performed using the processor. The method further includes estimating the amount of hydrocarbon in the earth formation using the calculated amount of hydrocarbon liquid condensate, the estimating being performed using the processor.
摘要:
A method includes acquiring formation fluid sample information including pressure, volume, and temperature. Monotonic formation fluid information is extracted from the formation fluid sample information and a pressure, volume, temperature information set is constructed. A curvature sequence is estimated using a first partial derivative and a second partial derivative of pressure with respect to volume. A first maxima is estimated from the curvature sequence, and the formation fluid property is estimated using the estimated first maxima. A method may include a volume acceleration sequence estimated using a first partial derivative and a second partial derivative of the volume with respect to pressure. A first maxima is estimated from the volume acceleration sequence, and the formation fluid property is estimated at least in part by using the estimated first maxima. A method may include establishing a first linear regression model and predicting a confidence interval.