Abstract: The invention relates to methods and computer-readable medium to implement computing the propagation velocity of seismic waves in the earth. The invention computes the propagation velocity of seismic waves in the earth, which is a condition of obtaining an accurate image of subsurface geology that can be used to prospect for oil and gas deposits. In an embodiment, the method in a host of determining the propagation angles of reflected seismic waves, including inputting data representing reflected seismic waves, inputting a propagation velocity field, computing propagation direction vectors of a source wave field and a receiver wave field using a downward continuation Fourier domain shot record migration using the data representing the reflected seismic waves and the propagation velocity field, and transforming the propagation direction vectors into propagation angles of reflected seismic waves.

Abstract: The invention relates to methods and computer-readable medium to determine seismic reflectivity attributes indicating the presence of hydrocarbons in earth. In several embodiments, the methods and computer-readable medium perform the steps of computing seismic reflectivity attributes includes inputting data representing reflected seismic waves and a volume of P-wave velocity, transforming the volume of P-wave velocity into a volume of bulk density, transforming the volume of P-wave velocity into a volume of S-wave velocity using amplitude information from the reflected seismic waves, and using the volume of S-wave velocity and the volume of P-wave velocity to compute the reflectivity attribute.

Abstract: The invention relates to methods and computer-readable medium for computing the propagation velocity of seismic waves in the earth. The invention computes the true propagation velocity of seismic waves in the earth, which is a condition of obtaining an accurate image of subsurface geology that can be used to prospect for oil and gas deposits. In an embodiment, the method of computing the propagation velocity of seismic waves in earth, includes providing an estimate of the propagation velocity, generating a time shift gather using a depth migration at a plurality of locations of the earth, converting each of the time shift gathers to a semblance gather, transforming each semblance gather into a velocity gather whose energy peaks represent a root-mean-square average of the propagation velocity along the forward and backward path between earth's surface and a point of the subsurface geology, and converting the energy peaks to the propagation velocity.

Abstract: The invention relates to methods and computer-readable medium to implement computing the propagation velocity of seismic waves in the earth. The invention computes the true propagation velocity of seismic waves in the earth, which is a condition of obtaining an accurate image of subsurface geology that can be used to prospect for oil and gas deposits. In an embodiment, the method of computing the propagation velocity of seismic waves in earth, includes providing an estimate of the propagation velocity, generating a time shift gather using a depth migration at a plurality of locations of the earth, converting each of the time shift gathers to a semblance gather, transforming each semblance gather into a velocity gather whose energy peaks represent a root-mean-square average of the propagation velocity along the forward and backward path between earth's surface and a point of the subsurface geology, and converting the energy peaks to the propagation velocity.

Abstract: The invention relates to methods and computer-readable medium to implement computing the propagation velocity of seismic waves in the earth. The invention computes the true propagation velocity of seismic waves in the earth, which is a condition of obtaining an accurate image of subsurface geology that can be used to prospect for oil and gas deposits. In an embodiment, the method of computing the propagation velocity of seismic waves in earth, includes providing an estimate of the propagation velocity, generating a time shift gather using a depth migration at a plurality of locations of the earth, converting each of the time shift gathers to a semblance gather, transforming each semblance gather into a velocity gather whose energy peaks represent a root-mean-square average of the propagation velocity along the forward and backward path between earth's surface and a point of the subsurface geology, and converting the energy peaks to the propagation velocity.