摘要:
A moveout correction process and stacking velocity estimation process to permit stacking of vertical seismic profile (VSP) data is disclosed wherein the primary reflection time is determined by using the two-way travel time, the root mean square velocity of acoustic pulses in the formation and the first arrival time of direct path acoustic pulses.
摘要:
A method for determining the lithology of subterranean structures based on attenuation of wave energy is disclosed which features a wave model based on a two-way solution to the wave equation rather than one-way solutions previously proposed. Rather than measuring amplitude of the wave as a function of its attenuation, energy flux density is measured which provides a two-way wave solution. In a preferred embodiment, pressure gradient measuring transducers are used to measure the energy flux density.
摘要:
A method for segregating and stacking vertical seismic profile data is disclosed wherein the offset difference between the well location and the position of the source is divided into equal segments, VSP moveout corrected data are placed in common reflection point bins and stacked.
摘要:
A seismic system is placed in a predetermined orientation with respect to a surface of a formation, and a low viscosity substance is introduced between the sensor system and the surface of the formation. The substance has a composition formulated for stiffening in situ by increasing viscosity to provide a mechanical bond and an acoustical signal transmission coupling between the sensor system and the formation. After completion of the seismic operation, the stiffened substance is contacted with a stimulus for breaking the stiffened substance and thereby break the mechanical bond. Thereafter, the sensor system is recovered.
摘要:
Seismic energy is generated at a multiplicity of source offsets from a borehole and offset VSP data is collected by an acoustic detector at a multiplicity of geophone depths for each source offset. The recorded data is sorted into Zero Source-Receiver (ZSR), common reflection point bins. Data from each offset VSP, ZSR common reflection point gather are dynamically moveout corrected with data adaptive parameters including reduced direct arrival times, dip, borehole deviation and stacking velocities. The moveout corrected VSP data are then stacked.
摘要:
An improved method of generating synthetic seismograms for use in determining the accuracy of hypothesized subterranean structures is disclosed. The method features defining hypothesized detector locations corresponding to real detector locations rather than interpolating from arbitrary detector locations generated by specifying of initial ray path angles as input data. The accuracy of the results is improved by elimination of interpolation.