A distance of a water flow path and a velocity of the water flow is calculated using data obtained from both a pulsed neutron sensor and distributed acoustic sensors. The two distance and velocity values are compared to obtain a first calculated distance and velocity. The distance of the water flow path and the velocity of the water flow are calculated using the Doppler data obtained from distributed Doppler sensors. The distance and velocity values are compared with the first calculated distance and first calculated velocity to obtain a second calculated distance and velocity values. The distance of the water flow path and the velocity of the water flow are calculated using temperature data obtained from distributed temperature sensors. The distance and velocity values are compared with the second calculated distance and velocity to determine a distance of a cement interface, and a velocity of a water flow therein.

Methods, apparatuses, and mediums related to a full-wavefield angle gather generation for high-contrast inter-thin bed modeling for reservoir characterizations of a survey region are provided. A method may include a well logging tool having one or more sonic generators and one or more well log data recording sensors in a wellbore. Sound waves may be generated using the one or more sonic generators in order to generate reflections in the survey region. Well log data, based on the reflections, may be received using well log data recording sensors, and the well log data may be transmitted to at least one memory. A method may perform, using a computer system, a full-wavefield angle gather generation. A method may generate, by a computer system, the high-contrast inter thin-bed models based on the full-wavefield angle gather.

Systems and methods for downhole signal filtering. A method for downhole signal filtering may comprise defining outliers as isolated values; providing thresholds; determining the outliers from a buffer; computing a difference in slowness between adjacent pairs of values; comparing the adjacent pairs of values to other values in a same window; determining if the adjacent pairs of values vary more than the threshold; assigning a 2D flag array a value of 0 if the adjacent pairs of values vary more than the threshold; and computing a 75% percentile distribution for each adjacent pair of values to determine if each adjacent pair of values are the outliers.

This invention relates to a method and a device for determining a combined proportion cube from a first meshed proportion cube and a second meshed proportion cube. The invention combines some facies models giving vertical probabilities and some facies models giving horizontal probabilities. This determination is particularly efficient in the presence of a zero probability in one of these models and is capable of respecting the mathematical constraint according to which the sum of each row and each column in the final proportion model must be equal to a predetermined maximum value.

A method comprising: conveying a downhole tool in a tubing that is positioned in a casing that is positioned to form an annulus between the casing and a wall of a wellbore formed in a subsurface formation, wherein a cement with unknown bonding condition exists in the annulus, wherein the downhole tool includes at least one transmitter and a receiver array physically positioned in different azimuthal directions; emitting, from the at least one transmitter, a first and second acoustic transmissions in a first and second azimuthal directions; detecting, by the receiver array, a first acoustic response and a second acoustic response that is derived from the first and second acoustic transmissions, wherein the second azimuthal direction is orthogonal to the first azimuthal direction; determining a dipole wellbore resonance based on the first and acoustic responses; and evaluating a property of the cement based on the dipole wellbore resonance.

Systems and methods for cement evaluation by determining a shear velocity of a shear wave (26) propagating within a medium (20) located between a formation (12) and a casing (13) in a borehole (11) are presented. The method can include positioning an ultrasonic transducer array (21) in the borehole inside the casing. The method can also include in a pushing mode, generating a shear wave in the medium with the ultrasonic transducer array inside the casing. The method can also include in an interrogation mode, measuring a shear velocity of the shear wave in the medium with the ultrasonic transducer array. The shear velocity may be used to determine whether the medium is solid or liquid.

A method for de-blending seismic data associated with an interface located in a subsurface of the earth, includes receiving blended seismic data E generated by firing N source arrays according to a pre-determined sequence Seq; selecting N sub-datasets SDn from the blended seismic data E; interpolating each selected sub-dataset SDn to reference positions ref, where the blended seismic data E is expected to be recorded, to generate interpolated data k; de-blending, in a processor, the interpolated data k to generate de-blended data o; and generating an image of the interface of the subsurface based on the de-blended data o.

In accordance with embodiments of the present disclosure, systems and methods for taking acoustic/ultrasonic wave measurements of a wellbore using a downhole tool equipped with microelectromechanical (MEM) transducers are provided. The MEM transducers may include a plurality of MEM transmitters (e.g., MEM speakers) and a plurality of separate MEM receivers (e.g., MEM microphones). These MEM transducers may be disposed in arrays proximate an outer surface of the downhole tool to collect acoustic/ultrasonic wave measurements of the full circumference of a wellbore. Due to their small size, large numbers of MEM transducers may be distributed radially around the downhole tool. Such an arrangement of sensors may enable the downhole tool to perform measurements of the entire wellbore without the downhole tool needing to be rotated, leading to an increased signal-to-noise ratio of the measurements.

An acoustic logging tool includes a support structure and a set of acoustic transducers coupled to the support structure. The set of acoustic transducers includes a first acoustic transducer and a second acoustic transducer facing the same direction. Each of the first and second acoustic transducers includes a substrate having a first end, a second end, a first side, and a second side. Each acoustic transduce further includes a first piezoelectric element coupled to the first side of the substrate and a second piezoelectric element coupled to the second side of the substrate. The first and second ends of the substrate extend beyond the first and second piezoelectric elements and are fixed to the support structure.

A method for borehole measurements may comprise receiving one or more signals from a linear receiver array, computing an arctan of a Hilbert Transform, isolating a first arriving energy, selecting a reference instantaneous phase on a reference receiver, finding the reference instantaneous phase for the linear receiver array, computing a relative travel time shift, combining a reference pick time with a relative time, and determining a travel time. A system for borehole measurements comprise a conveyance, a bottom hole assembly attached to the conveyance, a linear receiver array, wherein the linear receiver array is disposed on the bottom hole assembly, and a computer system connected to the linear receiver array.