This disclosure describes a system and method for generating images and location data of a subsurface object using existing infrastructure as a source. Many infrastructure objects (e.g., pipes, cables, conduits, wells, foundation structures) are constructed of rigid materials and have a known shape and location. Additionally these infrastructure objects can have exposed portions that are above or near the surface and readily accessible. A signal generator can be affixed to the exposed portion of the infrastructure object, which induces acoustic energy, or vibrations in the object. The object with affixed signal generator can then be used as a source in performing a subsurface imaging of subsurface objects, which are not exposed.

Systems and methods include a method for deblending signal and noise data. A shot domain for actual sources, a receiver domain for virtual sources, and a receiver domain for actual sources are generated from blended shot data. A dictionary of signal atoms is generated. Each signal atom includes a small patch of seismic signal data gathered during a small time window using multiple neighboring traces. A dictionary of noise atoms is generated. Each noise atom includes a small patch of seismic noise data gathered during a small time window using multiple neighboring traces. A combined signal-and-noise dictionary is generated that contains the signal atoms and the noise atoms. A sparse reconstruction of receiver domain data is created from the combined signal-and-noise dictionary. The sparse reconstruction is split into deblended data and blending noise data based on atom usage to create deblended shot domain gathers for actual sources.

Disclosed are advantageous designs for highly-sparse seabed acquisition for imaging geological structure and/or monitoring reservoir production using sea surface reflections. The highly-sparse geometry designs may be adapted for imaging techniques using the primary and higher orders of sea surface reflection and may advantageously allow for the use of significantly fewer sensors than conventional seabed acquisition. The highly-sparse geometry designs may be relevant to 3D imaging, as well as 4D (“time-lapse”) imaging (where the fourth dimension is time). In accordance with embodiments of the invention, geophysical sensors may be arranged on a seabed to form an array of cells. Each cell in the array may have an interior region that contains no geophysical sensors and may be sufficiently large in area such that a 500 meter diameter circle may be inscribed therein.

A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.

Geophysical prospecting may be achieved using borehole seismic data and processing velocity seismic profiles using downward continuation to simulate the seismic source being at the depth of the borehole receivers. Such methods may involve collecting seismic data for a subterranean formation with at least one borehole receiver; grouping the seismic data into a one common receiver gather corresponding to each borehole receiver; performing a downward continuation on at least one of the common receiver gathers to produce corresponding downward continued common receiver gathers; performing a normal moveout analysis on at least one of the downward continued common receiver gathers to produce corresponding semblance velocity spectra; and analyzing at least one of the semblance velocity spectra for a zone of interest in the subterranean formation.

This disclosure describes a system and method for generating images and location data of a subsurface object using existing infrastructure as a source. Many infrastructure objects (e.g., pipes, cables, conduits, wells, foundation structures) are constructed of rigid materials and have a known shape and location. Additionally these infrastructure objects can have exposed portions that are above or near the surface and readily accessible. A signal generator can be affixed to the exposed portion of the infrastructure object, which induces acoustic energy, or vibrations in the object. The object with affixed signal generator can then be used as a source in performing a subsurface imaging of subsurface objects, which are not exposed.

In an example implementation, first seismic energy is generated using first seismic sources positioned on an earth's surface. First data including measurements of the first seismic energy is obtained from first geophones positioned at a first depth below the earth's surface. Second data including measurements of the first seismic energy is obtained from second geophones positioned on the earth's surface. Second seismic energy is generated using second seismic sources positioned on an earth's surface and proximal to the second geophones. Third data including measurements of the second seismic energy is obtained from third geophones positioned at the first depth below the earth's surface. A propagation of the first seismic energy along a first path is estimated based on the first, second and third data. One or more characteristics of the target are determined based on the estimate.

Disclosed are advantageous designs for highly-sparse seabed acquisition for imaging geological structure and/or monitoring reservoir production using sea surface reflections. The highly-sparse geometry designs may be adapted for imaging techniques using the primary and higher orders of sea surface reflection and may advantageously allow for the use of significantly fewer sensors than conventional seabed acquisition. The highly-sparse geometry designs may be relevant to 3D imaging, as well as 4D (“time-lapse”) imaging (where the fourth dimension is time). In accordance with embodiments of the invention, geophysical sensors may be arranged on a seabed to form an array of cells. Each cell in the array may have an interior region that contains no geophysical sensors and may be sufficiently large in area such that a 500 meter diameter circle may be inscribed therein.

This disclosure describes a system and method for generating images and location data of a subsurface object using existing infrastructure as a source. Many infrastructure objects (e.g., pipes, cables, conduits, wells, foundation structures) are constructed of rigid materials and have a known shape and location. Additionally these infrastructure objects can have exposed portions that are above or near the surface and readily accessible. A signal generator can be affixed to the exposed portion of the infrastructure object, which induces acoustic energy, or vibrations in the object. The object with affixed signal generator can then be used as a source in performing a subsurface imaging of subsurface objects, which are not exposed.

Systems and methods include a method for deblending signal and noise data. A shot domain for actual sources, a receiver domain for virtual sources, and a receiver domain for actual sources are generated from blended shot data. A dictionary of signal atoms is generated. Each signal atom includes a small patch of seismic signal data gathered during a small time window using multiple neighboring traces. A dictionary of noise atoms is generated. Each noise atom includes a small patch of seismic noise data gathered during a small time window using multiple neighboring traces. A combined signal-and-noise dictionary is generated that contains the signal atoms and the noise atoms. A sparse reconstruction of receiver domain data is created from the combined signal-and-noise dictionary. The sparse reconstruction is split into deblended data and blending noise data based on atom usage to create deblended shot domain gathers for actual sources.