Abstract: A method of migrating seismic data using offset checkshot survey measurements. The offset checkshot survey measurements involve raypaths similar to the migration raypaths for the seismic data, and are used to determine direct arrival traveltimes to receivers in a borehole. Embodiments of the invention provide for direct use of the traveltimes in migration, or indirect use of the traveltimes in migration via construction of a migration velocity model. The velocity model embodiments further provide for either traveltime error correction via use of interpolated error functions or construction of migration error tables. The invention can be employed for time, depth or Kirchhoff migration, in either two or three dimension, and in either prestack or poststack applications. The invention may be used to migrate any type of seismic data, including compressional-wave, shear-wave, and converted-wave seismic data.

Abstract: The disclosed invention provides a method for recovering hydrocarbons from a subterranean formation by injecting an emulsion, comprising oil and water, into the formation. More specifically, the emulsion is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers. Carbon dioxide or another gas may be added to the emulsion to adjust the emulsion's viscosity to the desired level.

Abstract: A method of migrating seismic data using offset checkshot survey measurements. The offset checkshot survey measurements involve raypaths similar to the migration raypaths for the seismic data, and are used to determine direct arrival traveltimes to receivers in a borehole. Embodiments of the invention provide for direct use of the traveltimes in migration, or indirect use of the traveltimes in migration via construction of a migration velocity model. The velocity model embodiments further provide for either traveltime error correction via use of interpolated error functions or construction of migration error tables. The invention can be employed for time, depth or Kirchhoff migration, in either two or three dimension, and in either prestack or poststack applications.

Abstract: A compliant pile system for supporting the vertical weight of a guyed tower structure installed in a body of water. The pile system is comprised of at least one pile element which in turn is comprised of a pile jacket and a pile member. The pile jacket extends from one point in the structure to a second point which lies above the first point and is attached at only one point to the structure. The pile member passes through the pile jacket and is forced into the marine bottom and is attached only at its upper end to the pile jacket. In one modification, the pile jacket is comprised of an odd number of concentrically positioned sleeves with the pile member being affixed to the top of the innermost sleeve and the outermost sleeve being affixed only at its bottom to the structure. The sleeves, if more than one, are attached to each other at their respective alternate ends.

Abstract: A tether for securing a buoyant structure to the ocean floor. The tether includes a cable or a plurality of cables whose weight is at least partially supported by a buoyancy tank.

Abstract: A method for horizontal mating of multiple floating sections of an offshore platform using a single point mooring is disclosed. The single point mooring is installed at a predetermined mating site. The first section of the platform is transported to the mating site. Anchor handling vessels tow the section to the single point mooring and connect it to that mooring. Subsequent sections of the platform are then transported to the mating site while an anchor handling vessel attends to the horizontally floating moored sections. When all sections have been mated together at the mating site, the platform is disconnected from the single point mooring and towed to the installation site.