Abstract: Processes are described for providing a data set useful for performing analysis of reflection attribute variation among traces in a window of three-dimensional seismic data, wherein the traces have a reflection point assigned thereto and wherein the traces represent recordings from shot-receiver pairs having various azimuth angles. According to one embodiment, the process comprises: assigning an offset value to a plurality of traces; fitting a substantially conical surface having a major and a minor axis to the data of the traces within the window, wherein: the major axis of the cone represents the azimuth direction having the lowest variation in the reflection attribute, and the minor axis of the cone represents the azimuth direction having the highest variation in the reflection attribute; assigning a coordinate set to the surface, wherein the coordinate set is related to a survey geometry of the data; and comparing the reflection attribute variation as a function of offset and azimuth.

Abstract: An apparatus and method are provided for ensuring good coupling and vertically planting of seismic receivers while substantially reducing the need for interconnecting wires and costly surveys. The apparatus includes an acquisition unit (AU) 20 for measuring seismic energy and a planting member 12 for engaging and planting the AU 20. An electronic surveying instrument 14 is coupled to the planting member 12 for determining the location of the AU 20. An installer 16 plants the AU 20 in the terrain 22 in near vertical alignment using the planting member 12. Once the AU 20 is planted in near vertical alignment, coordinates are downloaded from the electronic survey unit to locate the planted AU 20.

Abstract: A method for producing high vertical resolution seismic images from crosswell data is disclosed. In accordance with one aspect of the disclosure, a set of vertically spaced, generally horizontally extending continuous layers and associated nodes are defined within a region between two boreholes. The specific number of nodes is selected such that the value of a particular characteristic of the subterranean region at each of the nodes is one which can be determined from the seismic data. Once values are established at the nodes, values of the particular characteristic are assigned to positions between the node points of each layer based on the values at node within that layer and without regard to the values at node points within any other layer. A seismic map is produced using the node values and the assigned values therebetween. In accordance with another aspect of the disclosure, an approximate model of the region is established using direct arrival traveltime data.

Abstract: The present invention enables both deep marine seismic surveys and site seismic surveys to be performed simultaneously. A survey vessel tows a first seismic array (6, 16, 20) for a deep survey and a second seismic array (6, 16, 20) for the site survey. The arrays are operationally distinct but may share common physical components.

Abstract: A method for acquisition of seismic data from an area surveyed using a group of seismic energy sources and a group of seismic streamer cables, particularly a marine area, includes forming a first group A from at least two elements of either seismic energy sources S or seismic streamer cables C having a spacing X between said elements, forming a second group B from at least two of the other elements of sources S or cables C than that forming group (A), spacing the elements in group B a distance equal to X multiplied by the number of elements in group A, forming a group C from at least two subgroups each consisting of a group A, spacing said subgroups in group C in distance equal to the distance between two elements in group B multiplied by the number of elements in group B, the spacing between two adjacent subgroups being equal to the lateral distance between midpoints between the subgroups, and forming further groups as desired D, E, F etc.

Abstract: A system for acquiring and processing seismic data comprises source-means for generating sound waves and receiver-means for recording as data those waves as reflected from sub-surface interfaces, and means for processing the recorded data operable to generate sets of actual data each individually associated with specific sub-surface reflection points, order the data-sets in accordance with receiver and source-means separation, process each data-set to generate additional data intermediate the recorded data, and re-order each data-set and additional data in accordance with receiver and source-means separation for further processing. Each data-set is applied to a filter to generate said additional data intermediate of the recorded actual data. The filter is selected from the group comprising linear, quadratic or spline interpolation filters, frequency space (f-x) filters, tau-p filters, smart filters artificially intelligent filters, neural network filters and (preferably) sinc filters.

Abstract: This invention provides a method for performing three dimensional seismic surveys. In one configuration, receiver lines containing equally spaced receiver stations run in one direction while the source station lines run orthogonal to the receiver station lines. The receiver stations and/or the source stations are offset to obtain a desired spatial sampling (number of bins) or multiplicity of the common mid points. In an alternate configuration, the receiver line spacing is offset by a fraction of the source station spacing and/or the source line spacing is offset by a fraction of the receiver station spacing to obtain the desired spatial sampling. These configurations provide higher spatial sampling (smaller bins) compared to the conventional geometries. The smaller bins may be combined to obtain folds (multiplicity) which is sufficient to provide desired seismic imaging while preserving the benefits provided by the higher spatial sampling by the method of the present invention.

Abstract: The seismic profile system and method using vertical sensor arrays relate to obtaining a seismic profile under two highly reflective boundaries. The system includes a source of seismic energy disposed beneath the air/water boundary, a first pair of sensors arranged in vertical relation and spaced apart by a predetermined vertical spacing distance, and a second pair of sensors similarly situated and spaced from the first pair by a predetermined horizontal spacing distance. The first and second pairs of sensors are disposed below at least two highly reflective boundaries, which may be the air/water boundary and a mud/water boundary. According to the method, the source is moved between two points and data is collected from the first and second pairs of sensors.

Abstract: This invention provides a method for performing three dimensional seismic surveys. In one configuration, receiver lines containing equally spaced receiver stations run in one direction while the source station lines run diagonal to the receiver station lines. The receiver stations and/or the source stations are offset to obtain a desired spatial sampling (number of bins) or multiplicity of the common mid points. In an altemate configuration, the receiver line spacing is offset by a fraction of the source station spacing and/or the source line spacing is offset by a fraction of the receiver station spacing to obtain the desired spatial sampling. These configurations provide higher spatial sampling (smaller bins) compared to the conventional geometries. The smaller bins may be combined to obtain folds (multiplicity) which is sufficient to provide desired seismic imaging while preserving the benefits provided by the higher spatial sampling by the method of the present invention.

Abstract: A broadline seismic survey is carried out by positioning a plurality of areal arrays of seismic detectors along each of a plurality of broadline receiver lines along the surface of the earth. Array centers along an inline direction of each receiver line are staggered by one-half of an array interval from array centers along the inline direction of adjacent receiver lines. Each detector array on a given receiver line is elongated in a cross-line direction to such receiver line to effect an areal array coverage between broadline centers of the adjacent receiver lines being on opposite sides of the given receiver line. The seismic detectors in each array are connected in common to a recording means.

Abstract: A method of seismic surveying uses seismic waveguides in the earth. Seismic energy is transmitted from outside the waveguide and detected within the waveguide or vice-versa. Coupling of energy between the outside and the inside of the waveguide is effected by energy leakage at coupling sites where the waveguide departs from planarity. The method analyzes seismic signals to determine the position and nature of coupling sites and the propagation characteristics of the waveguide.

Abstract: A seismic directional sensor for solid-borne sound has at least one geophone with pronounced directional characteristic. The measuring electrical vibration signals, which are obtained at different circumferential angular positions of the radial longitudinal axis of the geophone and are to be compared with one another, are correlated with the direction of a seismic ray extending at right angles to the longitudinal axis of the geophone, which is ineffective in its neural circumferential angular position.The neutral circumferential angular position is determined by the ratio of the amplitude of the measuring signals which are determined on both sides adjacent to the neutral circumferential angular position in effective circumferential angular positions of the geophone. The vibration pattern of the measuring signals is antiphase in relation to the respective other side.

Abstract: Method of vertical seismic profiling in drilling operations utilizing the drill bit for a source of seismic energy without any break in drilling operations. The noise of the drill bit and reflections of the noise in the formation are recorded with the aid of a geometrically extended array of receivers which are provided in a predetermined matrix group. The received signals are analyzed according to velocity and migration principles per se on the basis of differences in reception times, by which the noise signature of the drill bit can be determined at any desired location during drilling operations and extracted from the traces. The remaining received signal frequencies and signal amplitudes are analyzed in relation to their deviation in time, the signals being grouped according to time differences corresponding to focusing on certain areas in the formation.

Abstract: Method and system for creating a vertical seismic profile (VSP) whereby the spacing interval between units, either seismic sources or receivers, in a borehole increase exponentially as their distance from the surface increases, and the spacing interval between units, either seismic sources or receivers, along the surface of the earth decreases exponentially as their distance from the surface intercept of the wellbore increases. In a preferred embodiment of this invention, the common depth point (CDP) fold of the data gathered is substantially flattened across the reflectors surveyed.

Abstract: A method for high-resolution seismic recording with increased bandwidth using detectors planted at shallow depths below the earth's surface. In one embodiment, an optimum depth where the amplitudes of high frequency signals increase relative to that of the noise during high-resolution recording is determined, geophones are then planted at that optimum depth and signals are recorded at that depth. To find this optimum depth, detectors are planted at various depths below the earth's surface in order to record the signals at those various depths. The frequency spectra for each detected signal is generated and a velocity profile of the depths covered by the detectors is also generated from the signals. The bandwidth of the frequency spectra and the velocity profile are used to determine a depth for planting the detectors that is closer to the earth's surface than the depths previously considered.

Abstract: When a record mark portion arranged on the upstream side of a data area is reproduced, the peak value of a reproduction signal of the record mark portion is compared with a reference level. An overwrite preventing circuit is arranged so as to output an inhibiting signal for inhibiting data writing when the comparison output exceeds a predetermined level. With this preventing circuit, a data portion need not be checked in a read mode prior to a write mode.

Abstract: A novel method of geophysical exploration is provided whereby shot points and receiver locations are positioned such that seismic data resulting therefrom can advantageously be processed employing 3-D processing techniques to obtain a better image of the earth's subsurface structure. In one embodiment, shot points, or alternatively, receiver locations are arranged along generally sawtooth or zig zag lines so that common midpoint bins of seismic signals include a generally uniform distribution of source-receiver pair azimuths. In another embodiment, both the shot points and receiver locations are arrayed along generally alternating, sawtooth or zig zag lines.

Abstract: A method for conducting a three-dimensional subsurface seismic survey utilizing a plurality of seismic receivers arranged in an orthogonally uniform pattern is disclosed. A predetermined pattern of shotpoints is arranged such that every point in the surface area of interest is sampled over a desired range of offsets and a full range of azimuths. The utilization of shotpoints outside the pattern of receivers allows examination of a subsurface area which is greater than the area of the pattern itself. The output of each receiver in the pattern is simultaneously recorded for seismic energy applied to the surface of the earth. Where the area of interest is quite large, a multitude of patterns of seismic receivers may be utilized to ensure coverage of the entire area.

Abstract: A method for the determination and deconvolution of the signature of an unknown, non-impulsive source signal. The method supposes that that an array of receivers is positioned at the earth's surface to detect and record the seismic signals resulting from the interaction of the source with the earth's subsurface. The traces of data recorded are time-shifted by an amount determined by a coherency analysis of the data. The signal is estimated from the time-shifted data with a weighting factor applied at each trace. A deconvolution filter is determined from the estimate and is weighted at each frequency according to the strength of the source at that frequency. The filter is then applied to the time-shifted data.

Abstract: An inventive method for simultaneously collecting depth-of-focus vertical seismic profiling (VSP) data and three-dimensional surface seismic data is disclosed. At least one seismic sensor is deployed at a predetermined depth of a borehole and raised in increments determined by the survey. A seismic source and a plurality of seismic sensor may be deployed at the surface along a partial arc offset from the top of the borehole by a distance inversely proportional to the depth of the sensor in the borehole. The seismic source generates a seismic signal at a plurality of points in a circular path around the borehole. Once a circle has been completed, the borehole sensor is raised, and the seismic signal generator and sensors are moved to the next largest circular path and the process is repeated. The seismic signals are simultaneously recorded by the borehole sensor and the sensors deployed in the arcuate path.

Abstract: A 3-D radial seismic survey method is described suitable for accurately defining by migration processing an area having a dome-like subsurface structure. Radial survey lines are plotted with polar symmetry with respect to a center position at the center of the dome, such lines traversing the steep dip in all directions at approximate right angles. Hence, the developed data is efficiently acquired data useful for defining the structure. Bisecting survey lines may be provided as the original lines diverge to satisfy sampling requirements for migration. Data is acquired and sorted into bins that are annulus sectors and which are maintained sufficiently uniform in size to be within a maximum-to-minimum ratio of 2-to-1. Seismic source and receiver lines may be coincident or angularly offset.

Abstract: Disclosed is an array of seismic energy receiver elements spaced specifically for attenuation of horizontally traveling seismic waves. In one embodiment, the rows of seismic energy receiver elements are spaced apart a crossline distance d and have a total crossline extent D, and d is less than the velocity divided by the maximum frequency of the noise to be attenuated and D is greater than the velocity divided by the minimum frequency of the noise to be attenuated. In another embodiment, two or more arrays of seismic energy receiver elements are interleaved. Also disclosed herein is a method for processiong seismic energy signals to attenuate predetermined wavelengths of seismic waves.

Abstract: Three-dimensional seismic prospecting is conducted using a less than complete multifold array of seismic sources and receivers which are positioned so that the resulting system of linear static connection equations according to common depth point are continuously coupled.

Abstract: A receiver array for detecting seismic reflections is composed of geophones of several different natural frequencies divided into subarrays having lengths compatible with the natural frequencies of their geophones and the seismic wavelengths at the recording site. This system provides both frequency and spatial filtering at the sensors so as to enhance the signal-to-noise ratio of broad-band seismic signals.

Abstract: A pulse is applied sequentially to each geophone input line to the stator of a CDP switch. A pulse detector is connected to the first output line of the CDP Switch cursor. A counter counts the number of pulses applied to inactive input lines before a pulse is detected by the pulse detector. The pulse count is the geophone group number of the first active geophone group.

Abstract: A method for deriving seismic information from over a relatively large expanse of land to determine relevant strike, dip, velocity and related information. The method consists of the utilization of a plurality of strike, dip, velocity (SDV) cross patterned source-receiver arrays disposed at spaced known locations over a selected terrain, thereafter to derive localized and offset seismic data relative to selected pairs or groups of the SDV cross patterns with further signal processing to smooth and integrate strike, dip and velocity information over a specific substratum. The method utilizes information as derived from each SDV cross pattern, as well as offset seismic signal information derived from source/receiver combinations spanning two selected SDV cross patterns.

Abstract: A geophone is disclosed which includes at least two transducers having axes which are perpendicular to each other for sensing vertical and horizontal in-line components of seismic waves. In one arrangement, the geophone includes a signal processor which includes active circuit elements responsive to the transducer output for suppressing ground roll components included in the transducer outputs. At least one of transducer output signals with ground roll signal components suppressed therefrom is connected to a remote location for recording. When more than one signal is to be sent from the geophone to the remote recording location, a mulliplexer is provided at the geophone for transmission of a plurality of geophone output signals to the remote location over a single transmission path, such as a dual-conductor transmission line. Analog and digital versions of the geophone are disclosed.

Abstract: The present invention provides for the accurate mapping of shallow crustal earth formations by means for refractive seismic waves to identify structure as well as elastic parameters of the strata undergoing survey to indicate deposits or ore, marker rock, economic minerals and the like. In one aspect of the present invention, a "roll-along" technique is used in the field, such technique being both practical and economical. In accordance with another aspect of the invention, there is a provision for (i) accurate separation and determination of seismic shear and compressional responses using two-dimensional hodographs; (ii) stacking displays that allow for accurate identification of shape of the surveyed strata; and (iii) final depth displays of the refracting bed segments associated with seismic shear and compressional wave velocities as well as Poisson's ratio to indicate presence of ore, marker rocks, economic minerals and the like.

Abstract: The present invention provides for the accurate mapping of shallow crustal earth formations by means for refractive seismic waves to identify structure as well as elastic parameters of the strata undergoing survey to indicate deposits of ore, marker rock, economic minerals and the like. In one aspect of the present invention, a "roll-along" technique is used in the field, such technique being both practical and economical. In accordance with another aspect of the invention, there is a provision for (i) accurate separation and determination of seismic shear and compressional responses using three-dimensional hodographs; (ii) stacking displays that allow for accurate identification of shape of the surveyed strata; and (iii) final depth displays of the refracting bed segments associated with seismic shear and compressional wave velocities as well as Poisson's ratio to indicate presence of ore, marker rocks, economic minerals and the like.

Abstract: The present invention provides for the accurate mapping of shallow crustal earth formations by means for refractive seismic waves to identify structure, elastic parameters and lithology of the strata undergoing survey to indicate deposits of ore, marker rock, economic minerals and the like. After a "roll-along" technique has been used in the field to collect the refraction data and preliminary processing steps undertaken in which there are provisions for (i) accurate separation and determination of seismic shear and compressional responses; (ii) stacking displays that allow for accurate identification of shape of the surveyed strata; and (iii) final depth displays of the refracting bed segments associated with seismic shear and compressional wave velocities as well as Poisson's ratios, in accordance with the present invention, additional processing then occurs.

Abstract: A method is provided for obtaining wide band seismograms made from a plurality of narrow band seismic surveys using vibrator type sources. Several different narrow frequency band seismograms are obtained using vibrator type signal sources. The narrow band seismogram having different frequency band responses are stacked, or added together, to provide a single wide band seismogram having improved signal to noise characteristics.

Abstract: A method of seismic exploration comprises transmitting waves from transmission sources into the medium to be explored and picking up signals in a receiver and recording these as traces, the signals being produced by reflection in the medium, the sequential transmission of the sources taking place at intervals less than the reflection time of the longest transmitted waves, the repeated transmission of any one source taking place at intervals at least equal to the said reflection time and therein being an intercorrelation function of a series of transmission instants of all the sources and a series of transmission instants of any one of the sources to give a relationship between the maximum peak amplitude and the secondary residue amplitude greater than a predetermined value and grouping the recorded traces corresponding to the same reflection point, adjusting the traces in relation to the associated source providing the information relating to the reflection point and adding together the adjusted traces relati

Abstract: A method for removing an undesired surface wave from a reflected wave in a method for seismic exploration is accomplished by placing first and second detector arrays at a location on the surface of the earth in the direction of movement of the surface wave. The array has a length less than the length of the shortest wave length of the interfering wave to be eliminated. Signals from both arrays are recorded and processed by first adding the received signals to form a first output, subtracting added signals to form a second output, shifting one of the output signals by 90.degree., adjusting its amplitude and subtracting the phase shifted and adjust signal from the remaining signal thereby removing the surface wave.

Abstract: A seismic type electrical multiconductor cable. It is made up with a predetermined length of cable, and has a number of geophone takeout connectors spaced along that length of cable. These takeouts are electrically connected to individual geophone circuits. Half go to pig-tail connected plugs at each end, and there are program circuits that may be plugged into the pig-tail plugs.By arranging the takeouts in pairs, physically on the same conductor but electrically isolated, only half the number of conductors are needed. There are additional conductors in the cable with multi-circuit connectors at each end. The cables are symmetrical and may be laid out end-to-end. A spread of cables would be made with connection to a recording station centrally of the spread.

Abstract: A novel array of vertically and horizontally spaced hydrophones is shown which is capable of high ratio of desired signal to noise because of good directional sensitivity when used with any seismic source. Alternatively, a novel directionally sensitive array of vertically and horizontally spaced seismic sources is disclosed for use in seismic surveying with any spread of hydrophones or geophones, again attaining a high ratio of desired signal to noise. A reception pattern (in the first case) and a radiation pattern (in the second place) is produced which essentially eliminates reception or radiation at all frequencies except for waves within a predetermined angle with respect to the array. The sensitivity is essentially constant within such angle for all frequencies and essentially zero outside it.

Abstract: A method of locating near-surface underground chambers, rooms, caves, pits, tubes, faults in surface rocks, and the like, using acoustic techniques is disclosed. For mapping large areas, a survey grid for transmitter transducer placement first is laid out over the area of interest.A transmitting transducer is coupled to the bedrock at one of the grid sites, and acoustic waves are generated in the earth by operation thereof. Portable acoustic receiving means, including a receiving transducer, are used to detect acoustic waves from the transmitter at a plurality of receiving sites surrounding the transmitting station. Transmitted acoustic waves from the transmitting site received by the receiving transducer are converted to electrical signals by the receiving transducer and recorded for subsequent use. Following operation of the receiving means at each receiving site surrounding the transmitter transducer, the received signals are compared to determine any differences in their magnitudes.