George P. Moeckel

Method for moveout correction and stacking velocity estimation of offset VSP data

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.

ACORN : APL to C on real numbers

a prototype APL to C compiler ( ACORN : APL to C On Real Numbers) was produced while investigating improved tools for solving numerically intensive problems on supercomputers. ACORN currently produces code which runs slower than hand-coded Cray FORTRAN, but we have identified the major performance bottlenecks, and believe we know how to remove them. Although created in a short time on a limited budget, and intended only as a proof of the feasibility of compiling APL for numerically intensive environments, ACORN has shown that straightforward compiled APL will be able to compete with hand-optimized FORTRAN in many common supercomputer applications.

Restoration of structural cross-sections

Abstract Cross-section restoration transforms deformed stratigraphic boundaries (the cross-section) into a less deformed state at an earlier time in the structural history. It is best described by transformation equations which incorporate rigid translation and rotation plus deformation. These equations can be linear (affine) or non-linear. Strain is a function of the transformation constants, and linear transformation equations produce homogeneous strain. Most existing restorations use linear transformations, and many assume simple shear strain, a special case of linear transformation. Linear transformations (such as simple shear) cannot, in general, preserve both area and continuity in cross-section restoration: i.e. if area is constrained, there will be gaps and overlaps between different regions of the restored cross-section. If gaps and overlaps are eliminated, area cannot be constrained. Cross-section restoration can be achieved by solving a geometric boundary value problem using quadrilateral domains with non-linear transformations. The geometric boundary conditions are specified by knowlege of the position of an undeformed layer boundary and the pin line. Strain measured in the field can be incorporated as an initial condition. Discontinuities (faults) can be incorporated into the solution by treating them as an internal boundary without gaps or overlaps.

Coupling and recovering seismic detection sensors

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.