Systems and methods for improving seismic data analysis using dithering techniques.

Description

1 / 20 Systems and methods for improving seismic data analysis using dithering techniques. CROSS-REFERENCE TO RELATED REQUESTS

[0001] This application claims priority from U.S. Provisional Patent Application No. 63 / 456,130, filed March 31, 2023, which is incorporated herein by reference. FUNDAMENTALS

[0002] This disclosure refers generally to the carrying out of multiple types of seismic surveys in water. More specifically, this disclosure refers to the exploration of geological areas using enhanced seismic acquisition techniques.

[0003] This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present disclosure, which are described and / or claimed below. It is believed that this discussion will help provide the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Consequently, it is understood that these statements will be read in that light, and not as admissions of the prior art.

[0004] Seismic exploration in certain water areas with complex geological structures can be challenging. Various water properties (e.g., shallowness) and geological complexities can create difficulties in seismic data acquisition (e.g., surveys) and post-acquisition data processing (e.g., noise attenuation, subsurface imaging, velocity model building). Dithering during seismic acquisitions can improve the noise attenuation processing involved in seismic data analysis. However, some dithering techniques may reduce the efficiencies at which noise attenuation can be achieved. SUMMARY

[0005] A system of one or more computers can be configured Petition 870250103868, dated 11 / 13 / 2025, page 9 / 33 2 / 20 to perform specific operations or actions by virtue of having software, firmware, hardware, or a combination thereof installed in the system which, in operation, causes or makes the system perform the actions. One or more computer programs may be configured to perform particular operations or actions by virtue of including instructions which, when executed by data processing equipment, cause the equipment to perform the actions. A general aspect includes a method for locating a coherent seismic signal from data collected during a seismic survey.The method also involves projecting dithers having a predetermined distribution within a dither range, where the dither range is chosen for the seismic survey, where a lower limit of the dither range is relative to the fraction of nominal firing times of seismic wave sources in the seismic survey, and where an upper limit of the dither range is a larger value compatible with seismic survey constraints, where the seismic survey includes nominal source positions. The method also involves projecting survey positions for each of the sources, adding the projected dithers to the nominal positions relative to an underlying grid of the seismic survey. The method also involves activating each of the sources at the projected survey positions.The method also includes receiving a plurality of seismic waves generated as a result of source activations, where the sources are activated to generate the seismic waves and where the sources include an adjacent pair of sources. The method also includes locating a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity-promoting domain. Other embodiments of this aspect include computer systems, apparatus, and corresponding computer programs registered on one or more computer storage devices, each configured to perform the actions of the methods.

[0006] Another general aspect includes a computer system for locating a coherent seismic signal from data collected during a Petition 870250103868, dated 11 / 13 / 2025, page 10 / 33 3 / 20 Seismic survey. The computing system also includes one or more processors, and a memory system may include one or more non-transient computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computing system to perform operations. The operations include projecting dithers having a predetermined distribution within a dither range, where the dither range is chosen for the seismic survey, where a lower limit of the dither range is relative to the fraction of the nominal firing times of seismic wave sources in the seismic survey, and where an upper limit of the dither range is a larger value compatible with the constraints of the seismic survey, where the seismic survey includes nominal positions of the sources.The operations also include projecting survey positions for each of the sources, adding the projected dithers to the nominal positions relative to an underlying seismic survey grid. The operations also include activating each of the sources at the projected survey positions. The operations also include receiving a plurality of seismic waves generated as a result of the source activations, where the sources are activated to generate the seismic waves and where the sources may include an adjacent pair of sources. The operations also include locating a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity promoter domain.Other embodiments of this aspect include computer systems, appliances, and corresponding computer programs stored on one or more computer storage devices, each configured to perform the actions of the methods.

[0007] Yet another general aspect includes a non-transient, computer-readable means of locating a coherent seismic signal from data collected during a seismic survey. The means stores instructions that, when executed by one or more processors in a computing system, cause the computing system to perform operations. Petition 870250103868, dated 11 / 13 / 2025, page 11 / 33 4 / 20 The operations involve designing dithers with a predetermined distribution within a dither range, where the dither range is chosen for the seismic survey, with a lower limit of 4 seconds (for a total dither of ±2 seconds relative to the nominal firing times of seismic wave sources in the seismic survey). The upper limit of the dither range is a larger value compatible with seismic survey constraints. The seismic survey includes nominal source positions, and the upper limit of the dither range is based on a maximum separation time between when the sources are activated. The dither range is based on, for example, but not limited to, source spacing, the speed of a vessel towing the sources, and source cycle times.

[0008] In some configurations, seismic waves propagate downwards to subsurface geological structures, and the sources include, for example, but are not limited to, one or more source arrays and / or a plurality of air guns. In some configurations, the seismic survey includes ocean floor node sensors, and the ocean floor node sensors include one or more geophones. The one or more geophones are, for example, but not limited to, single-component, two-component, or three-component. In some configurations, the ocean floor node sensors include hydrophones, and the seismic survey includes one or more streamers traversing the water. In some configurations, the vessel tows the one or more streamers along a sail line, each of the one or more streamers includes one or more streamer sensors, and the one or more streamer sensors may include one or more hydrophones.One or more hydrophones create electrical signals in response to changes in water pressure caused by reflected seismic waves reaching the hydrophones. In some settings, the seismic survey includes one or more near-field hydrophones close to the sources, and the seismic survey includes one or more seismic sensors in one or more boreholes drilled into a geological structure. Petition 870250103868, dated 11 / 13 / 2025, p. 12 / 33 5 / 20 underground. In some configurations, one or more seismic sensors include fiber optic sensors, geophones, and / or hybrid sensors, including both fiber optic sensors and geophones. In some configurations, source light signals are provided to the fiber optic sensors, and the source light signals may include laser pulses, wavelength-adjustable lasers, vertical cavity surface emission lasers, external cavity lasers, and / or distributed feedback lasers. In some configurations, hybrid sensors are arranged along a cable deployed in one or more wells, and the one or more sensors measure deformations caused by seismic waves traveling along a sensor array. The one or more sensors are measuring ground movements caused by seismic waves traveling along the sensor array. The one or more seismic sensors convert the received light data into digital signals.The sources are activated to generate seismic waves. In some configurations, the sources are activated randomly. One or more seismic sensors receive reflected seismic waves and measure the reflected seismic waves.

[0009] The operations also include receiving the constraints, including environmental and instrumental constraints, where environmental constraints include an energy threshold above which no more energy can be injected over a period of time, and the amount of energy that can be injected is based on a minimum separation between two sources and the energy threshold. The operations also include designing survey positions for each of the sources, adding the designed dithers to the nominal positions relative to an underlying seismic survey grid. The operations also include maintaining a cycle time between the sources based on a seismic survey design. The operations also include activating each of the sources at the designed survey positions.The operations also include receiving a plurality of seismic waves generated as a result of source activation, where the sources are activated to generate the seismic waves and where the sources may include an adjacent pair of sources. The operations also... Petition 870250103868, dated 11 / 13 / 2025, page 13 / 33 6 / 20 include locating a coherent signal from received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity promoter domain. The operations also include displaying the coherent signal. The operations also include performing a well location action in response to the coherent signal. Other embodiments of this aspect include computer systems, apparatus, and corresponding computer programs registered on one or more computer storage devices, each configured to perform the actions of the methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features, aspects and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the attached drawings, in which similar features represent similar parts in all drawings, where:

[0011] FIG. 1 illustrates a schematic diagram of a seismic survey in water using multiple seismic measurements according to the modalities described in this document;

[0012] FIG. 2 illustrates an example dither design that optimizes the separation between consecutive sources, according to the modalities described herein;

[0013] FIGS. 3A-3C illustrate the design of multiple vessels from multiple exemplary sources, according to the modalities described herein;

[0014] FIG. 4 is a pictorial example of the large dither range and dither distributions, according to embodiments of the present disclosure; and

[0015] FIGS. 5A and 5B are flowcharts of a method according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0016] One or more specific modalities will be described below. To provide a concise description of these modalities, not all features of a real implementation are described in the report. Petition 870250103868, dated 11 / 13 / 2025, p. 14 / 33 7 / 20 descriptive. It should be appreciated that in the development of any such implementation, as in any engineering project or undertaking, numerous implementation-specific decisions must be made to achieve the specific objectives of the developers, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Furthermore, it should be noted that such a development effort may be complex and time-consuming, but despite this, it would be a routine design, manufacturing, and production task for people of ordinary skill in the art who have the benefit of this disclosure.

[0017] When introducing elements of various modalities of this disclosure, the articles “a”, “an”, “the” and “referred to” are intended to mean that there is one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements that are not the elements listed. It should be noted that the terms “multimedia” and “media” may be used interchangeably in this document.

[0018] Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings and figures. In the following detailed description, numerous specific details are set forth in order to provide a complete understanding of the invention. However, it will be evident to those skilled in the art that the invention can be practiced without these specific details. In other cases, well-known methods, procedures, components, circuits and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0019] Furthermore, it will be understood that, although the terms first, second, etc. may be used in this document to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first object could be called a second object or step, and so on. Petition 870250103868, dated 11 / 13 / 2025, page 15 / 33 8 / 20 Similarly, a second object could be called a first object or stage, without departing from the scope of the disclosure. The first object or stage, and the second object or stage, are both objects or stages, respectively, but should not be considered the same object or stage.

[0020] The terminology used in describing the techniques in this document is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this description and the accompanying claims, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and / or”, as used herein, refers to and encompasses any possible combinations of one or more of the associated listed items. It will further be understood that the terms “includes”, “including”, “comprises” and / or “comprising”, when used in this descriptive report, specify the presence of indicated features, parts, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, parts, steps, operations, elements, components and / or groups thereof.Furthermore, as used in this document, the term "if" can be interpreted as meaning "when" or "after" or "in response to the determination" or "in response to the detection," depending on the context.

[0021] Attention is now directed to processing procedures, methods, techniques, and workflows that conform to certain modalities. Some operations in the processing procedures, methods, techniques, and workflows disclosed in this document may be combined and / or the order of some operations may be changed.

[0022] FIG. 1 illustrates a schematic diagram of a seismic survey in water using multiple seismic measurements. A body of water may include a surface 10 and a water bottom 12. The water depth in the body of water may vary from a few meters to any suitable number of Petition 870250103868, dated 11 / 13 / 2025, p. 16 / 33 9 / 20 meters. Multiple subsurface layers (e.g., subsurface layers 14 and 15) may lie beneath the waterbed 12. Geological formations, such as subsurface formations 16 and 18 embedded within the subsurface layers, may contain hydrocarbon deposits. Seismic data acquired from the water seismic survey can be used to image the waterbed 12, subsurface layers 14 and 15, and subsurface formations 16 and 18. Images of subsurface geological structures may provide indications of hydrocarbon deposits.

[0023] Water seismic surveying may include ocean floor node (OBN) measurement employing multiple OBNs 20 on the water floor 12. The OBNs may be deployed (e.g., using remotely operated vehicles - ROVs) at selected locations and form a certain geometry (e.g., an OBN patch with a network size of 200 meters by 200 meters). Each of the OBNs 20 may include one or more OBN sensors. The OBN sensors may include one or more geophones (e.g., single-component, two-component, and three-component geophones). In some embodiments, the OBN sensors may also include hydrophones.

[0024] One or more seismic source vessels may be used in seismic water surveying. For example, a source vessel 22 towing a seismic source 25 and another source vessel 32 towing another seismic source 35 may be used to create seismic waves that propagate downwards in subsurface geological structures. Each of the seismic sources 25 and 35 may include one or more source arrays and each source array may include a certain number of air guns.

[0025] Water seismic surveying may also include streamer measurement employing multiple streamers traversing the water. For example, source vessel 22 may tow multiple (e.g., two, four, six, eight, or ten) streamers 23 along one sail line, and source vessel 32 may tow multiple streamers 33 along another sail line. A Petition 870250103868, dated 11 / 13 / 2025, p. 17 / 33 10 / 20 streamer measurements can be acquired using shots fired by seismic sources 25 and 35. Each streamer may include multiple streamer sensors. For example, each of the floating cables 23 may include floating cable sensors 24, and each of the floating cables 33 may include floating cable sensors 34. The floating cable sensors 24 and 34 may include hydrophones that create electrical signals in response to changes in water pressure caused by reflected seismic waves reaching the hydrophones.

[0026] Seismic water surveying may also include near-field hydrophone (NFH) measurement employing multiple NFHs close to seismic sources. For example, an NFH 26 may be deployed in close proximity to seismic source 25 and another NFH 36 may be deployed in close proximity to seismic source 35.

[0027] Water seismic surveying may also include vertical seismic profile (VSP) measurement using seismic sensors (e.g., fiber optic sensors, geophones, or hybrid sensors) in one or more wells. For example, an array of hybrid sensors including fiber optic sensors 46 and geophones 48 may be laid along a steel cable 44 deployed in a well 42 of a well 40, which may be drilled into the subsurface formation 16. Similar seismic sensors may be deployed in another well 50, which may be drilled into the formation 18. The fiber optic sensors 46 may measure deformations caused by reflected or refracted seismic waves moving along the hybrid sensor array. Geophone 48 can measure ground motion (e.g., particle motion, such as velocity and acceleration) caused by seismic waves moving along the hybrid sensor array.

[0028] During a seismic water survey, the seismic source 25 can be activated to generate seismic waves 60 traveling downwards to subsurface geological structures. When the seismic waves 60 reach the water bottom 12, a portion of the seismic energy contained in the seismic waves 60 is reflected by the water bottom 12. The reflected waves 62 travel in a direction Petition 870250103868, dated 11 / 13 / 2025, p. 18 / 33 11 / 20 ascend and reach different sensors, such as floating cable sensors 24 and 34, near-field hydrophones 26 and 36, and fiber optic sensors 46, where they are measured by corresponding sensors. Another portion of the seismic energy contained in the transmitted seismic waves 64 propagated through the bottom water 12 to the subsurface layer 14. A portion of the seismic energy contained in the transmitted waves 64 is reflected by the subsurface formation 16. The reflected waves 66 move upward and reach the different sensors, where they are measured by the corresponding sensors.

[0029] It should be noted that the elements described above in relation to water seismic surveying are exemplary elements. For example, some seismic surveying modalities may include additional or fewer elements than those shown. In some modalities, water seismic surveying may include a different number of source vessels. In some modalities, separate receiving vessels may be used to tow the streamers. In some modalities, streamer measurement may be acquired independently of OBN measurement for operational or logistical reasons.

[0030] Seismic data acquired simultaneously from different sensors can be collected and processed by a processing system 80. The processing system 80 may include one or more seismic recorders 82, an interrogator 84, a processor 86, a memory 88, a storage 90, and one or more displays 92. The one or more seismic recorders 82 may receive ocean floor node (OBN) data from OBNs 20, streamer data from streamer sensors 24 and 34, near-field hydrophone (NFH) data from NFHs 26 and 36, and a portion of vertical seismic profile (VSP) data from geophones 48. The interrogator 84 may receive another portion of VSP data from fiber optic sensors 46. The collected data may be processed by the processor 86 using processor-executable code stored in memory 88 and storage. 90. The processed data can be stored in storage 90 for later use. Petition 870250103868, dated 11 / 13 / 2025, page 19 / 33 12 / 20 processing results can be displayed via one or more of the 92 displays.

[0031] The interrogator 84 may include a light source 94 that can provide source light signals (e.g., laser pulses) to the fiber optic sensors 46. For example, the light source 94 may include wavelength-tunable lasers (e.g., semiconductor lasers), such as distributed reflector Bragg (DBR) laser, vertical cavity surface emitter (VCSEL) laser, external cavity laser, distributed feedback (DFB) laser, or other suitable lasers. The interrogator 84 may also include a light recorder 96 that can receive light signals (e.g., backscattered light signals associated with the local measurement of dynamic voltages caused by incident seismic waves) from the fiber optic sensors 46 and convert the light signals into electrical signals (e.g., using photodetectors).

[0032] The 86 processor may be any type of computer processor or microprocessor capable of executing computer executable code. 86 processors may include single-path processors, multi-path processors, or both. 86 processors may also include hardware-based processors, each including one or more cores. 86 processors may include general-purpose processors, special-purpose processors, or both. 86 processors may be communicatively coupled to other components (such as one or more seismic registers 82, interrogator 84, memory 88, storage 90, and one or more displays 92).

[0033] Memory 88 and storage 90 may be any suitable articles of manufacture that can serve as means for storing processor-executable code, data, or the like. These articles of manufacture may represent computer-readable media (e.g., any suitable form of memory or storage) that can store processor-executable code used by processor 86 to execute the techniques presently disclosed. Memory 88 and storage 90 Petition 870250103868, dated 11 / 13 / 2025, page 20 / 33 13 / 20 can also be used to store described data (e.g., fiber sensor data, geophone data), various other software applications for seismic data analysis and data processing. Memory 88 and storage 90 can represent non-transient computer-readable media (e.g., any suitable form of memory or storage) that can store processor-executable code used by processor 86 to perform various techniques described in this document. It should be noted that non-transient only indicates that the medium is tangible and not a signal.

[0034] One or more monitors 92 may operate to represent visualizations associated with the software or executable code being processed by the processor 86. The monitor 66 may be any suitable type of monitor, such as a liquid crystal display (LCD), plasma display or an organic light-emitting diode (OLED) display.

[0035] It should be noted that the components described above in relation to the 80 processing system are exemplary components and the 80 processing system may include additional or fewer components as shown. For example, the 80 processing system may include one or more communication interfaces to send commands to different seismic acquisition systems and to receive measurements from different seismic acquisition systems.

[0036] Bearing in mind the above, it should be noted that seismic water surveys are carried out using simultaneous source acquisition to acquire data from longer displacements, keeping the acquisition cost low. In some embodiments, seismic sources 25 and 35 and streamer sensors 24 can be positioned according to a source-receiver design layout on a periodic grid, while a relatively small dither (e.g., 100 mms - 1 s) can be applied between the firings of seismic sources 25 and 35 to create randomness in the interference noise. The random interference noise can be removed to identify Petition 870250103868, dated 11 / 13 / 2025, p. 21 / 33 14 / 20 the origin signal in the resulting seismic data acquisition.

[0037] It should be noted that seismic surveys may be limited by environmental and instrumental constraints, such as the inability to inject energy above a certain threshold or to maintain a certain amount of time to allow activation time between the firing of consecutive sources. As such, the addition of dithers between source activations can aid in locating a coherent signal that is distinct from the randomly distributed interference noise during source separation processing in the sparsity domain. In other words, identifying the coherent signal becomes relatively easier using dithering techniques compared to not using dithering techniques.

[0038] With this in mind, the small amount of randomization provided in the interference noise due to dithers can result in a somewhat coherent appearance of the interference noise. However, it can be difficult to identify signals of this noise during source separation processing operations. Thus, to mitigate the relatively small amount of noise interference injected into seismic data caused by dithers, seismic data processing and analysis techniques can carefully process the concurrent data to ensure that a coherent signal hidden beneath the strong and somewhat coherent interference noise can be identified. These processing and analysis techniques can be time-consuming and imprecise, depending on the similarities between the desired signals and the interference noise.

[0039] Consequently, in some embodiments of the present disclosure, the seismic survey design may include a survey acquisition with higher dithers following the compressive detection theory. That is, in some survey acquisition designs, minimum and maximum oscillations within the oscillation range and a minimum activation time (e.g., cycle time) between sources, as determined strictly based on environmental and instrument constraints, may be specified by some Petition 870250103868, dated 11 / 13 / 2025, page 22 / 33 15 / 20 user, and this interval can be used to determine oscillation values. In this way, the determined dither values ​​can be randomly selected without actually providing the resulting interference noise, which can maximize randomization in the interference and randomize the dither separation between consecutive sources.

[0040] To improve or increase randomization in interference and randomization in oscillation separation between consecutive sources, in some embodiments, the seismic survey design may maintain the cycle time between sources while selecting oscillation values ​​that randomly optimize the separation between consecutive sources, while also accounting for cycle time. The term “dithers,” as used herein, is the time offset to introduce randomization relative to the nominal firing times. Dithers can be positive or negative. The range of dithers is computed as twice the maximum absolute value of dithers allowed in the calculated distribution.For a given scenario with one or more sources on one or multiple vessels, in configurations according to this disclosure, the dither range is maximized while adhering to the restrictions of the maximum nominal time interval for a single source or even exceeding the nominal time interval for a single source among one or more sources. In some configurations, the lower limit of the dither range may include any value from four seconds (+ / - 2 seconds relative to nominal trigger times) up to the maximum nominal time interval for a single source, and is adjusted with specific considerations adapted to the survey requirements and its operational parameters.In some configurations, the upper limit of the dither range is subject to additional restrictions imposed by hardware, software, environmental considerations, and specific survey configurations, such as, but not limited to, near-field hydrophone requirements.

[0041] In some configurations, the dither value range may extend up to a maximum separation time in which a subsequent source Petition 870250103868, dated 11 / 13 / 2025, page 23 / 33 16 / 20 can be activated. For example, three sources can be activated sequentially one after the other within 6 seconds of separation (e.g., separation time), including a 3-second cycle time. This activation design results in a total recording period of 18 seconds before the same source is activated again. In some embodiments, sources can be activated randomly, so that a minimum dither time is 0 seconds and the maximum dither time is the nominal time difference between two consecutive sources (e.g., 0-6), while optimizing the separation between sources. Dither is the perturbation relative to the nominal. The dither range is restricted by acquisition systems or operational requirements or environmental regulations. Additionally, random dither generation can be continuously repeated in pairs of 3 sources until the entire source line is covered.In this way, numerous possible randomized dither scenarios within 6 seconds along each source line can be realized. As an example, FIG. 2 illustrates a dither generation example for three source scenarios where each source line is 60 km long. The illustrated dither design optimizes the separation between consecutive sources.

[0042] FIGS. 3A-3C illustrate ideal positions of the three sources, while maximizing dithers. Specifically, FIGS. 3A-3C illustrate a conventional multi-source, multi-vessel design for the marine environment, where three sources on each vessel are activated. FIG. 3A illustrates a flip-flop-flap activation every 16.66 m, and FIG. 3B illustrates a flip-flip-flip activation with a dither value of ± 1 second. FIG. 3C illustrates grid locations using a maximum possible number of dithers selected according to the embodiments of the present disclosure, while optimizing source separation between consecutive sources.

[0043] Continuing with the three-source example mentioned above, the lifting design can include dithers that are projected globally, so that the dither range of each active source is connected to the way in which dithers are imposed on previously activated sources. As a result, Petition 870250103868, dated 11 / 13 / 2025, page 24 / 33 17 / 20 The resulting dithers provide higher randomization of interference noise along the source line, as opposed to assigning minimum and maximum dithers to neighboring sources based strictly on cycle time, as performed in other survey designs. That is, in some embodiments, the dither time employed between each source activation can be randomized to be of different values ​​within the range indicated by the design. In fact, by including dither times up to the maximum separation time amount, the resulting interference noise can be maximized, thus allowing signal identification during source separation processing of seismic data analysis to be more efficient.

[0044] By randomizing the dither times between source activation using the time range up to and including the maximum value of the source activation time interval, the interference noise from different sources can be highly randomized, making source separation processes more robust and efficient compared to traditional seismic survey designs.

[0045] In another embodiment, seismic survey designs can be prepared to ensure that each source along a respective candle line has an equal probability of having maximum dither value, regardless of the length of the respective candle line. In this way, the present embodiments described here allow randomization to remain consistent throughout the candle line. As a result, later sources on a candle line avoid having lower dither values ​​compared to previously activated sources.

[0046] Referring now to FIG. 4, dithers can be positive or negative and belong to the dither distribution for a given survey. In some configurations, the range of the dither distribution for the entire survey is twice the maximum absolute value of dithers allowed in the calculated distribution. For example, as shown in the N2 401 dither distribution, if the range value is 6 seconds, the dither distribution will be ±3 seconds. In some configurations, a type of Petition 870250103868, dated 11 / 13 / 2025, page 25 / 33 An 18 / 20 dither distribution with a fixed range value is designed for a survey, meaning that for a given survey the range value is a number, for example, 6 seconds, giving a ±3 second distribution.

[0047] For each survey, the distribution is expanded and the band value is maximized, providing a design of the dither distribution in which the band value is as large as possible. This band value is maximized within limits, where the lowest value is 4 seconds, as shown in N1 403, while the highest limit is a nominal time separation for a given source, but is adjusted with specific considerations tailored to the survey requirements and its operational parameters. For example, if an N4 405 dither distribution, with a band of 15 seconds (±7.5 second dither distribution for the survey), is selected, but due to, for example, but not limited to, environmental constraints, hardware constraints, and near-field hydrophone requirements, the N2 401 dither distribution with a band value of 6 seconds (+ / - 3 seconds) is the resulting distribution.

[0048] Referring now to FIG. 5A, the 500 method for locating a coherent seismic signal from data collected during a seismic survey may include, but is not limited to, projecting 502 dithers having a predetermined distribution within a dither band. The dither band is chosen for the seismic survey. The lower limit of the dither band is relative to the fraction of the nominal firing times of the seismic wave sources in the seismic survey, and the upper limit of the dither band is a larger value compatible with the seismic survey constraints. The seismic survey includes nominal positions of the sources, and the upper limit of the dither band is based on a maximum separation time between when the sources are activated. The 500 method includes receiving 504 constraints, including environmental and instrumental constraints.Environmental constraints include, for example, but are not limited to, an energy threshold above which no more energy can be injected over a period of time. The amount of energy that can be injected is based, for example, but not limited to, on a... Petition 870250103868, dated 11 / 13 / 2025, page 26 / 33 19 / 20 minimum separation between two sources and the energy threshold. The 500 method also includes projecting 506 survey positions from each of the sources, adding the projected dithers to the nominal positions relative to an underlying seismic survey grid, and maintaining a 508 cycle time between the sources based on a seismic survey design.

[0049] Referring now to FIG. 5B, method 500 includes activating 510 each of the sources at the projected survey positions and receiving 512 a plurality of seismic waves generated as a result of the source activation. The sources are activated to generate the seismic waves and include an adjacent pair of sources. Method 500 includes locating 514 a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity-promoting domain, displaying 516 the coherent signal, and performing 518 a well-location action in response to the coherent signal. The well-location action may be based on the coherent signal. The well-location action may be or may include the generation and / or transmission of a signal (e.g., using a computer system) that instructs or causes a physical action to occur at the well-location.Actions in well location may or may not include performing physical actions at the well location. Physical actions may include selecting where to drill a well hole, drilling the well hole, varying the weight and / or torque on a drill bit that is drilling the well hole, varying the drilling trajectory of the well hole, varying the concentration and / or flow rate of a fluid pumped into the well hole, or something similar.

[0050] It should be noted that although the preceding description is detailed with reference to a marine seismic survey acquisition, the modalities presented here can also be applied to land-based acquisition surveys. That is, dithering techniques can be applied between vibrator firings and other land-based seismic acquisition components, as described above.

[0051] Although only certain characteristics of the disclosed modalities Petition 870250103868, dated 11 / 13 / 2025, page 27 / 33 Although the 20 / 20 claims have been illustrated and described in this document, many modifications and changes will occur for those skilled in the art. It should therefore be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the present disclosure.

[0052] The techniques presented and claimed in this document are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible, or purely theoretical. Furthermore, if any claims appended to the end of this descriptive report contain one or more elements designated as “means for [performing] [a function]…” or “step for [performing] [a function]…”, it is intended that such elements be interpreted under 35 USC 112(f). However, for any claims containing elements designated in any other way, it is intended that such elements not be interpreted under 35 USC 112(f). Petition 870250103868, dated 11 / 13 / 2025, pp. 28 / 33

Claims

1 / 7 CLAIMS 1. A method for locating a coherent seismic signal from data collected during a seismic survey, the method characterized in that it comprises: projecting dithers having a predetermined distribution within a dither range, wherein the dither range is chosen for the seismic survey, wherein a lower limit of the dither range is relative to the fraction of the nominal firing times of seismic wave sources in the seismic survey and wherein an upper limit of the dither range is a larger value compatible with the constraints of the seismic survey, wherein the seismic survey includes nominal positions of the sources; projecting survey positions of each of the sources by adding the projected dithers to the nominal positions relative to an underlying grid of the seismic survey; activating each of the sources at the projected survey positions;Receive a plurality of seismic waves generated as a result of source activations, wherein the sources are activated to generate the seismic waves and wherein the sources include an adjacent pair of sources; and locate a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity-promoting domain.

2. Method according to claim 1, characterized in that: the upper limit of the dither band is constrained by a maximum separation time between source activations, the maximum separation time is related to the underlying grid and a nominal time separation between two consecutive activations for a given source, and the lower limit of the dither band is 4 seconds, which is ±2 seconds around a point on the underlying grid. Petition 870250103866, dated 11 / 13 / 2025, p. 9 / 24 2 / 7 3. A method, according to any one of claims 1 to 2, characterized in that it further comprises: maintaining cycle times between sources based on seismic surveys, wherein the upper limit of the dither range is based on a spacing of the sources or a distance between firings of the sources, a speed of a vessel towing the sources, and the cycle times of the sources.

4. A method according to any one of claims 1 to 3, characterized in that: seismic waves propagate downwards to underground geological structures, and the sources include one or more source arrays.

5. A method, according to any one of claims 1 to 4, characterized in that the sources include a plurality of air cannons.

6. A method, according to any one of claims 1 to 5, characterized in that the seismic survey includes ocean floor node sensors, the ocean floor node sensors including one or more geophones, the geophones being of single component, two component or three component types, the ocean floor node sensors including hydrophones.

7. A method according to any one of claims 1 to 6, characterized in that the seismic survey includes one or more streamers traversing the water, wherein a vessel tows the one or more streamers along a sail line, each of the one or more streamers including one or more streamer sensors, the one or more streamer sensors comprising one or more hydrophones, the one or more hydrophones creating electrical signals in response to changes in water pressure caused by reflected seismic waves reaching the hydrophones.

8. Method, according to any one of claims 1 to 7, characterized in that the seismic survey comprises one or more Petition 870250103866, dated 11 / 13 / 2025, p. 10 / 24 3 / 7 near-field hydrophones in the vicinity of the sources.

9. A method according to any one of claims 1 to 8, characterized in that: the seismic survey includes one or more seismic sensors in one or more boreholes drilled into an underground geological structure, the one or more seismic sensors including fiber optic sensors, geophones and hybrid sensors including both fiber optic sensors and geophones, wherein the source light signals are provided to the fiber optic sensors, wherein the source light signals comprise laser pulses, wavelength-tunable lasers, vertical cavity surface emission lasers, external cavity lasers or distributed feedback lasers, wherein the hybrid sensors are arranged along a cable deployed in one or more boreholes, the one or more seismic sensors measuring deformations caused by seismic waves traveling along an array of sensors,One or more sensors are measuring ground movements caused by seismic waves traveling along the sensor array, where one or more seismic sensors convert received light data into electrical signals, with sources being activated to generate seismic waves, the sources being activated randomly, and one or more seismic sensors receiving reflected seismic waves and measuring the reflected seismic waves.

10. A method, according to any of claims 1 to 9, characterized in that it comprises: receiving environmental and instrumental constraints, wherein the environmental constraints include an energy threshold above which no more energy can be injected during a pre-selected period of time, the amount of energy that can be injected is based on a minimum separation between two sources, and maintaining an amount of time that allows for activation time between consecutive firings of the sources; displaying the coherent signal; and executing a well location action in response to the coherent signal.

11. A computing system for locating a coherent seismic signal from data collected during a seismic survey, the computing system comprising: one or more processors; and a memory system comprising one or more non-transient computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computing system to perform operations, the operations comprising: projecting dithers having a predetermined distribution within a dither range, wherein the dither range is chosen for the seismic survey, wherein a lower bound of the dither range is relative to the fraction of nominal firing times of seismic wave sources in the seismic survey and wherein an upper bound of the dither range is a larger value compatible with seismic survey constraints, wherein the seismic survey includes nominal positions of the sources;To project survey positions for each of the sources by adding the projected dithers to the nominal positions relative to an underlying grid of the seismic survey; to activate each of the sources at the projected survey positions; to receive a plurality of seismic waves generated as a result of the source activations, wherein the sources are activated to generate the seismic waves and wherein the sources comprise an adjacent pair of sources; and to locate a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity-promoting domain.

12. Computing system, according to claim 11, characterized in that the upper limit of the dither band is constrained by a maximum separation time between source activations, Petition 870250103866, 11 / 13 / 2025, p. 12 / 24 5 / 7 the maximum separation time is related to the underlying grid and a nominal time separation between two consecutive activations for a given source, and the lower limit of the dither band is 4 seconds, which is ±2 seconds around a point on the underlying grid.

13. A computing system, according to any one of claims 11 to 12, characterized in that the upper limit of the dither range is based on a spacing of the sources or a distance between firings of the sources, a speed of a vessel towing the sources, and the cycle times of the sources.

14. A computing system according to any one of claims 11 to 13, characterized in that: seismic waves propagate downwards to underground geological structures, and the sources include one or more source arrays.

15. Non-transient computer-readable medium, characterized in that it is for locating a coherent seismic signal from data collected during a seismic survey, the non-transient computer-readable medium storing instructions which, when executed by one or more processors of a computer system, cause the computing system to perform operations, the operations comprising: projecting dithers having a predetermined distribution within a dither range, wherein the dither range is chosen for the seismic survey, wherein a lower limit of the dither range is ±2 seconds relative to the fraction of nominal firing times of seismic wave sources in the seismic survey and wherein an upper limit of the dither range is a greater value compatible with seismic survey constraints, wherein the seismic survey includes nominal positions of the sources,where the upper limit of the dither range is based on a maximum separation time between when the sources are activated, where the dither range is based on a Petition 870250103866, dated 11 / 13 / 2025, page. 13 / 24 6 / 7 source spacing, a vessel speed towing sources and source cycle times, where: seismic waves propagate downwards to subterranean geological structures, sources include one or more source arrays, sources include a plurality of air guns, the seismic survey includes ocean floor node sensors, the ocean floor node sensors including one or more geophones, the one or more geophones being single-component, two-component or three-component, the ocean floor node sensors including hydrophones, the seismic survey includes one or more streamers traversing the water, where the vessel tows the one or more streamers along a sail line,Each of the one or more streamers including one or more streamer sensors, the one or more streamer sensors comprising one or more hydrophones, the one or more hydrophones creating electrical signals in response to changes in water pressure caused by reflected seismic waves arriving at the hydrophones; the seismic survey includes one or more near-field hydrophones in the vicinity of the sources; the seismic survey includes one or more seismic sensors in one or more boreholes drilled into an underground geological structure, the one or more seismic sensors including fiber optic sensors, geophones and hybrid sensors including both fiber optic sensors and geophones, wherein the source light signals are provided to the fiber optic sensors, wherein the source light signals comprise laser pulses, wavelength-tunable lasers, vertical cavity surface emission lasers, external cavity lasers or distributed feedback lasers,wherein hybrid sensors are arranged along a cable deployed in one or more wells, the one or more sensors measuring deformations caused by seismic waves traveling along an array of sensors, the one or more sensors measuring ground movements caused by seismic waves traveling along the sensor array, wherein the one or more seismic sensors convert received light data into digital signals, the sources being activated to generate seismic waves, the sources being activated randomly, the one or more seismic sensors receiving reflected seismic waves and measuring the reflected seismic waves; to receive the constraints, including environmental constraints and instrumental constraints, where the environmental constraints include an energy threshold above which no more energy can be injected during a period of time.wherein the amount of energy that can be injected is based on a minimum separation between two sources and the energy threshold; project survey positions of each of the sources by adding the projected dithers to the nominal positions relative to an underlying seismic survey grid; maintain a cycle time between the sources based on a seismic survey design; activate each of the sources at the projected survey positions; receive a plurality of seismic waves generated as a result of source activation, wherein the sources are activated to generate the seismic waves and wherein the sources include an adjacent pair of sources; locate a coherent signal from the received seismic waves that is distinct from randomly distributed interference noise during source separation processing in a sparsity promoter domain; display the coherent signal; and perform a well location action in response to the coherent signal. Petition 870250103866from 11 / 13 / 2025, page 15 / 24,

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