G01V1/201

Method and system for simultaneous acquisition of pressure and pressure derivative data with ghost diversity
09791581 · 2017-10-17 · ·

A marine streamer spread for acquiring seismic data, the spread including a streamer having a first portion and a second portion; the first portion including both first pressure sensors and pressure derivative sensors for acquiring the seismic data; and the second portion including second pressure sensors. The first portion imparts ghost diversity to the seismic data by having a variable-depth profile and the pressure derivative sensors impart polarity diversity to the seismic data.

Calculation of mud angle for imaging wells with oil based muds

This disclosure may relate to a system and method for calculating the mud angle from a downhole device. A method for estimating a mud angle may comprise: disposing a downhole tool into a borehole; extending an arm of the downhole tool to a first location, wherein a pad is disposed on the arm; taking a first impedance measurement with at least one button electrode, wherein the button electrode is disposed in a button array, wherein the button array is disposed on the pad; extending the arm to a second location; taking a second impedance measurement with the at least one button electrode; transmitting the first measurement and the second measurement to an information handling system; and estimating the mud angle from the first impedance measurement and the second impedance measurement with an information handling system.

Systems and method for unmanned undersea sensor position, orientation, and depth keeping
09791862 · 2017-10-17 · ·

The methods and devices described herein provide a sensor array positioning system that may allow a user to program a series of sensor array locations, depths and orientations into a control center, which therein commands two or more unmanned surface or submarine vehicles which positions one or more sensor arrays. The devices consist of at least two unmanned vehicles, two or more tow cables, a flexible sensor array comprising one or more sensors, and one or more buoyancy engines. The unmanned vehicles may consist of a master vehicle and one or more slave vehicles, wherein the master vehicle commands the one or more slave vehicles.

Methods and systems for towing acoustic source sub-arrays
09823371 · 2017-11-21 · ·

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.

METHOD AND DEVICE FOR BOOSTING LOW-FREQUENCIES FOR A MARINE SEISMIC SURVEY
20170276774 · 2017-09-28 · ·

Systems and methods for boosting low content of received signals involve a vessel (102) towing port side (205) and starboard side (210) impulsive source arrays. The port side and starboard side impulsive source arrays are selectively actuated for a plurality of sequential shots having different signatures.

VARIABLE BUOYANCY CONTROL AND RECOVERY SYSTEM FOR SEISMIC DATA ACQUISITION
20170248722 · 2017-08-31 ·

A seismic apparatus includes one or more seismic cable systems configured to acquire seismic data, each seismic cable system having one or more of a cable jacket, a reservoir for a ballast fluid or other ballast medium, and an actuator or other transfer mechanism configured to transfer the ballast fluid between the reservoir and the seismic cable system during acquisition of the seismic data, e.g., where the ballast fluid is transferred to the seismic cable system within the cable jacket. A controller can be configured to adjust a buoyancy of the seismic cable system responsive to the transfer of the ballast fluid, e.g., where the internal volume expands or contract based on the fluid transfer.

Seismic sensor station

A housing for a seismic sensor station has a base and a removable lid, which when assembled together form a shell whereby the base and the removable lid both have a shell side and an exterior side. A sensor spike, protruding outward from the shell, may be attached to the base on the exterior side of the base. The housing is further provided with two cable docking ports, each allowing passage of a fiber optical cable from outside to inside the shell. The two cable docking ports are exclusively provided in the removable lid.

Clamp and bending strain relief apparatus and methods

Clamp and Bending Strain Relief (BSR) system and method are disclosed. One example of a system can include a clamp coupled to a cable. The clamp is configured to couple an apparatus to the cable while allowing the cable to pass continuously through the clamp. A BSR apparatus is coupled to the clamp and the cable by a housing.

Processes and systems for generating a high-resolution velocity model of a subterranean formation using iterative full-waveform inversion

This disclosure describes processes and systems for generating a high-resolution velocity model of a subterranean formation from recorded seismic data gathers obtained in a marine seismic survey of the subterranean formation. A velocity model is computed by iterative FWI using reflections, resolving the velocity field of deep subterranean targets without requiring ultralong offsets. The processes and systems use of an impedance sensitivity kernel to characterize reflections in a modeled wavefield, and then use the reflections to compute a velocity sensitivity kernel that is used to produce low-wavenumber updates to the velocity model. The iterative process is applied in a cascade such that position of reflectors and background velocity are simultaneously updated. Once the low-wavenumber components of the velocity model are updated, the velocity model is used as an input of conventional FWI to introduce missing velocity components (i.e., high-wavenumber) to increase the resolution of the velocity model.

STREAMER EQUIPMENT TENSION CONTROL
20170235004 · 2017-08-17 ·

An apparatus for acquiring survey data including streamer equipment comprising a lead-in cable; and a geophysical streamer with a plurality of geophysical sensors distributed along the geophysical streamer, including a forward geophysical sensor; a depressor coupled to the streamer equipment in front of the forward geophysical sensor; a variable tension control device coupled at a back end of the geophysical streamer; and a plurality of tension control system sensors. A method for acquiring survey data including obtaining data from tension control system sensors of a geophysical streamer system; identifying an adjustment to be made to one or more tension control factors of the geophysical streamer system to reduce or control vibrational behavior of streamer equipment of the geophysical streamer system making the adjustment to the one or more tension control factors; and acquiring survey data with the geophysical streamer system.