Wavelet estimation may be performed in a reservoir simulation model that is constrained by seismic inversion data and well logs. A synthetic seismic trace is generated along with an estimated wavelet. The reservoir simulation model is revised based on results from model comparisons to actual data or base seismic data and is then used to perform a wavelet estimation. The estimated wavelet may then be used to plan further production at the well site environment, additional production at additional well site environments or any other production and drilling operation for any given present or future well site environment.

A system and method for inspecting cement downhole in multi-casing wells. The method may comprise inserting an inspection device into a tube. The inspection device may comprise a plurality of transducers, wherein the plurality of transducers comprise one or more transducers. Further, the inspection device may comprise an inner tubing and at least one mount. The method for inspecting cement downhole may further comprise exciting the plurality of transducers, sweeping the plurality of transducers from a minimum frequency value to a maximum value, and matching frequency value of the plurality of transducers to a frequency value of a target structure.

A method can include receiving values of an inversion based at least in part on seismic amplitude variation with azimuth (AVAz) data for a region of a geologic environment; based at least in part on the received values, computing values that depend on components of a second-rank tensor a.sub.ij; selecting a fracture height for fractures in the geologic environment; selecting an azimuth for a first fracture set of the fractures; based at least in part on the values for the second-rank tensor a.sub.ij, the fracture height and the selected azimuth, determining an azimuth for a second fracture set of the fractures; and generating a discrete fracture network (DFN) for at least a portion of the region of the geologic environment where the discrete fracture network (DFN) includes fractures of the first fracture set and fractures of the second fracture set.

A computer-implemented method for updating subsurface models including: using an offset continuation approach to update the model, and at each stage defining a new objective function where a maximum offset for each stage is set, wherein the approach includes, performing a first stage iterative full wavefield inversion with near offset data, as the maximum offset, to obtain velocity and density or impedance models, performing subsequent stages of iterative full wavefield inversion, each generating updated models, relative to a previous stage, wherein the subsequent stages include incrementally expanding the maximum offset until ending at a full offset, wherein a last of the stages yields finally updated models, the subsequent stages use the updated models as starting models, and the full wavefield inversions include constraining scales of the velocity model updates at each stage of inversion as a function of velocity resolution; and using the finally updated models to prospect for hydrocarbons.

Production capability of cased hole perforations in a cased completed well lined with a casing in an under-pressured gas producing reservoir is tested. A sonde of a dipole shear or array sonic (full waveform) acoustic well logging tool is moved in a well bore of the cased completed well in the reservoir across a depth interval of interest, which covers cased hole perforations zones in the reservoir. The well logging sonde has in it an acoustic energy source and acoustic energy receivers. Responses are logged at depth intervals of interest to the transit of Stoneley waves along the casing walls from the acoustic energy source to the acoustic energy receivers. Measures of characteristics (e.g., travel time and attenuation) of the Stoneley wave are obtained. The responses are then processed to indicate production capability of the cased hole perforations.

Methods for inversion of seismic data to infer subsurface physical property parameters, comprising constructing an inhomogeneous anisotropy model and/or inhomogeneous V.sub.S/V.sub.P or V.sub.P/V.sub.S model; and inverting the seismic data in a sequential or simultaneous approach to obtain at least one subsurface physical property parameter using an elastic inversion algorithm and the inhomogeneous anisotropy model and/or inhomogeneous V.sub.S/V.sub.P or V.sub.P/V.sub.S model. Constructing an inhomogeneous anisotropy model may comprise deriving geobodies from at least one of seismic facies analysis, regional geologic information, or seismically derived earth models; and adjusting at least one of , , , or parameters of the elastic stiffness tensor matrix in a homogeneous anisotropy model in areas corresponding to the geobodies. Constructing an inhomogeneous V.sub.S/V.sub.P or V.sub.P/V.sub.S model may comprise deriving geobodies and adjusting values in a homogeneous V.sub.S/V.sub.P or V.sub.P/V.sub.S model in areas corresponding to the geobodies.

A method for generating acoustic images corrected for distortions caused by attenuation of the ultrasonic signal by the mud may comprise disposing a downhole tool into a borehole, transmitting a pressure pulse from at least one transducer into the borehole, recording an echo with the at least one transducer, measuring a travel time, measuring an amplitude, determining a geometry of the borehole, determining a location of the downhole tool in the borehole, calculating an incident angle, mapping a mud attenuation, and correcting an image. A system for generating acoustic images corrected for distortions caused by attenuation of the ultrasonic signal by the mud comprising a downhole tool that may comprise a measuring assembly, wherein the measuring assembly comprises at least one transducer and wherein the at least one transducer is configured to emit a pressure pulse and record an echo. The system may further comprise an information handling system.

Disclosed herein is a method for eccentricity correction. This method may dispose a downhole tool into a borehole. The downhole tool may comprise a measuring assembly that has at least one transducer, determining a beam pattern from the at least one transducer, determining a center of the measurement assembly in the borehole with the beam pattern, calculating a beam pattern factor with at least the beam pattern, calculating an angle factor with at least the beam pattern, calculating an eccentricity factor with at least the beam pattern factor and the angle factor, and creating an eccentricity corrected image with at least the eccentricity factor.

A method is provided for identifying and characterizing structures of interest in a formation traversed by a wellbore, which involves obtaining waveform data associated with received acoustic signals as a function of measured depth in the wellbore. A set of arrival events and corresponding time picks is identified by automatic and/or manual methods that analyze the waveform data. A ray tracing inversion is carried out for each arrival event (and corresponding time pick) over a number of possible raypath types to determine i) two-dimensional reflector positions corresponding to the arrival event for the number of possible raypath types and ii) predicted inclination angles of the reflected wavefield for the number of possible raypath types. The waveform data associated with each time pick (and corresponding arrival event) is processed to determine a three-dimensional slowness-time coherence representations of the waveform data for the number of possible raypath types, which is evaluated to determine azimuth position and orientation of a corresponding reflector, and determine the ray path type of the reflected wavefield. The method outputs a three-dimensional position and/or orientation for at least one reflector, wherein the three-dimensional position of the reflector is based on the two-dimensional position of the reflector determined from the ray tracing inversion and the azimuth position of the reflector determined from the three-dimensional slowness-time coherence representation. The information derived from the method can be conveyed in various displays and plots and structured formats for reservoir understanding and also output for use in reservoir analysis and other applications.

A method for adjusting a parameter of a wellbore operation includes: conveying a carrier through the wellbore; performing a resistivity measurement on the formation using a resistivity tool disposed on the carrier; performing an acoustic measurement on the formation using an acoustic tool disposed on the carrier; generating with a at least one processor a map of the formation using the resistivity measurement and the acoustic measurement, and adjusting the parameter using the map.