Pgs Geophysical As

Pgs Americas, Inc.

Andrew Samuel Long

Stig Rune Lennart Tenghamn

Christian Wilhelm Strand

Nizar Chemingui

Alejandro Antonio Valenciano Mavilio

Shaoping Lu

Manuel Beitz

Martin Widmaier

Norman Daniel Whitmore, Jr

Grunde Rønholt

Jostein Lima

William B Pramik

Steven Blake Campbell

Robert James Adams

Barbara Janina Danielsen

Barrett Moreing Cameron

Aloke K Mathur

Andrew F Lubrano

Sverre L Strandenes

Marine survey data can be acquired at a tow line. The tow line is designed to be coupled between a marine survey vessel and a towed object. A receiver is associated with the tow line and designed to receive marine survey data at a location of the tow line. The receiver can be an optical fiber or other type of receiver.

Marine survey data acquisition at a tow line

Methods for performing a marine survey of a subterranean formation using a hybrid combination of ocean bottom seismic ('OBS') receivers, wide towed sources, and moving streamers are described herein. In one aspect, a sail line separation in a crossline direction is determined based on an average streamer separation and number of streamers. An array of OBS receivers are deposited on a surface of a subterranean formation with an OBS receiver separation that is based on the sail line separation. Wide towed sources and streamers are towed above the array of OBS receivers behind a survey vessel that travels sail lines separated by the sail line separation. The wide towed sources may be activated above the array of OBS receivers. Wavefields reflected from the subterranean formation are recorded at the OBS receivers and receivers located in the streamers as seismic data.

Hybrid ocean bottom seismic receiver and streamer seismic data acquisition using wide towed sources

A method for a marine seismic survey can include towing streamers that are spaced apart in a cross-line direction by a streamer separation (L) and towing seismic source elements that are spaced apart in the cross-line direction by a source separation based on an integer (k), an inverse of a quantity of the seismic source elements (1/S), and the streamer separation as represented by (k+1/S)L. The seismic source elements can be actuated and seismic signals can be detected at each of a plurality of receivers on the streamers.

Cross-line source separation based on cross-line streamer separation

Geophysical survey methods. At least some of the example embodiments are methods of performing a marine geophysical survey including: towing a plurality of sensor streamers behind a tow vessel, each sensor streamer coupled to the tow vessel by a respective lead-in cable; towing, by the tow vessel, a plurality of lead vessels with each lead vessel pulling a respective seismic source, each lead vessel pulled by a respective tow cable and at least one intermediate cable; actuating the respective seismic sources pulled by the plurality of lead vessels; and gathering seismic data by each of the sensor streamers.

Geophysical survey systems and related methods

A method and apparatus for marine surveying including towing an electromagnetic source having an electromagnetic cross-talk zone and an entanglement zone; towing a plurality of pieces of seismic equipment, wherein each piece of seismic equipment is towed outside of the electromagnetic cross-talk zone and the entanglement zone; actuating the electromagnetic source; and while actuating the electromagnetic source, acquiring seismic survey data with the plurality of pieces of seismic equipment.

Combined seismic and electromagnetic survey configurations

Geophysical survey systems and methods. At least some of the example embodiments are systems including: a tow vessel with an onboard data acquisition system; a sensor streamer that defines a proximal end and a distal end, the sensor streamer extends behind the tow vessel, and the sensor streamer submerged in the body of water; a lead-in cable coupled on a first end to the tow vessel, and coupled on a second end to the sensor streamer; a lead vessel associated with the sensor streamer, the lead vessel floating at or near the surface of the body of water, and the lead vessel coupled to the sensor streamer by a tow cable; and a seismic source in the water behind the lead vessel, the seismic source coupled to the lead vessel by a source cable that extends from the lead vessel to the seismic source.

Acoustic source arrays and related methods. At least some of the example embodiments are methods including towing a first source sub-array comprising a first surface float, the first surface float defines a first connection point at a proximal end of the first surface float. The method may further include towing a second source sub-array comprising a second surface float, the second surface float defines a second connection point at a proximal end of the second surface float. And during the towing of the first and second source sub-arrays, the method may include maintaining a lateral separation between the first and second connection points of the first and second surface floats by a first strut, the first strut coupled between the first connection point of the first surface float and the second connection point of the second surface float.

Methods and systems for towing acoustic source sub-arrays

One embodiment relates to a technological process for identifying a potential subsurface structure below a body of water. Three-dimensional seismic sensor data that includes at least two measured components is obtained. Up-going and down-going wavefields comprising multiples wavefields are constructed from the three-dimensional seismic sensor data by applying wavefield separation. The up-going and down-going wavefields are extrapolated to a reflector surface below a water bottom. An imaging condition is applied at the reflector surface to generate images that include information from the multiples wavefields. Angle gathers are constructed, where each angle gather is constructed by gathering the images generated using the multiples wavefields for a range of illumination angles. Other embodiments, aspects and features are also disclosed.

Construction and application of angle gathers from three-dimensional imaging of multiples wavefields

In a seismic survey, idealized subsurface illumination is generated using idealized survey data. Then, the following three steps are performed during each of a sequence of time intervals during the seismic survey. First, an incremental portion of actual survey data is collected, using data acquisition equipment at a data acquisition location. Second, the incremental portion of actual survey data is communicated from the data acquisition location to a data processing location. Third, an incremental portion of actual subsurface illumination is generated using the incremental portions of actual survey data, to incrementally generate actual subsurface illumination at the data processing location. It is determined if additional data acquisition is desirable by comparison of the idealized subsurface illumination and the actual subsurface illumination, in the data processing location. Then, any desirable additional data acquisition is performed in the data acquisition location before the data acquisition equipment leaves the data acquisition location.

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West Perth, Australia

Andrew Samuel Long