Abstract: A abrasive jet perforating tool comprises a generally cylindrically shaped tube with a side, an upper portion, and a lower portion; a plurality of holes tapped and threaded into the side of the tube; threaded abrasive jets mounted in at least some of the plurality of threaded holes; protective plates mounted on the side of the tube around the abrasive jets; gauge rings that slide onto an outer diameter of the upper portion and the lower portion of the tube; and a mechanical casing collar locator connected to the upper portion of the tube.

Abstract: A seismic data set is processed by selecting a set of gathers in the seismic data set. A frequency independent constraint matrix is calculated in a first gather. A model solution in at least one second gather is calculated by using the constraint matrix in a high-resolution Radon transform.

Abstract: Near-offset and far-offset seismic data volumes are time-aligned by first selecting a plurality of time shifts. The near-offset and far-offset seismic data volumes are cross-correlated at the plurality of time shifts. An initial time-shift volume and a maximum correlation volume are created from the maximal cross-correlations at the plurality of time shifts. Areas of high time shift from the initial time-shift volume and areas of low cross-correlation from the maximum correlation volume are determined. The determined areas of high time shift and low cross-correlation are filtered from the initial time-shift volume, generating a filtered time-shift volume. The filtered time-shift volume is applied to the far-offset seismic volume to generate a time-aligned far-offset volume.

Abstract: A model seismic image of a subsurface seismic reflector is constructed, wherein a set of source and receiver pairs is located, and a subsurface velocity function is determined. Specular reflection points are determined on the subsurface seismic reflector for each of the source and receiver pairs. A Fresnel zone is determined on the subsurface seismic reflector for each of the specular reflection points, using the subsurface velocity function. One or more seismic wavelets are selected and a set of image points is defined containing the subsurface seismic reflector. A synthetic seismic amplitude is determined for each of the image points by summing the Fresnel zone synthetic seismic amplitude for all of the Fresnel zones that contain the image point, using the seismic wavelets. The model seismic image of the subsurface seismic reflector is constructed, using the synthetic seismic amplitudes at the image points.

Abstract: An apparatus and method for suppressing multiples in the collection of marine seismic data comprises at least one source positioned in the body of water; at least one receiver positioned in the body of water below the air-water interface and near the sources; a bubble diffuser positioned in the body of water so that the bubbles emitted by the bubble diffuser are positioned between the receivers and the air-water interface, wherein the emitted bubbles provide high acoustic reflection and substantially suppress specular reflection of seismic waves; and a control for activating the bubble diffuser during the collection of seismic data by the sources and receivers.

Abstract: A method for spectral balancing of near- and far-offset seismic data, whereby velocity and offsets are determined for the seismic data. First, an NMO stretch compensation filter is created by the following steps. A frequency spectrum of the near-offset seismic data is estimated and a stretch factor &bgr; is calculated for the frequency spectrum, using the velocity and the offsets. A stretched frequency spectrum of near-offset seismic data is calculated, based on the stretch factor &bgr;. The frequency spectrum of near-offset seismic data is divided by the stretched frequency spectrum of near-offset seismic data, generating a first frequency response filter. High frequency gain is limited in the first frequency response filter, generating a first gain-limited filter. The first gain-limited filter is convolved with a low pass filter, generating the NMO stretch compensation filter. Then the NMO stretch compensation filter is applied to the seismic data.

Abstract: Structural and stratigraphic discontinuities are identified in a 3-D volume of seismic data samples, by first selecting a plurality of directions containing a primary direction and at least one secondary direction. Next, one-dimensional, two-trace first discontinuity values are calculated along the primary direction for each seismic data sample in the 3-D data volume. Next, a series of sequentially less restrictive thresholds is defined, such that a significant portion, preferably at least approximately 10%, of the first discontinuity values satisfy the first threshold. This significant portion of first discontinuity values is then stored in an output discontinuity volume at the corresponding sample locations. The following steps are repeated for each remaining data sample until that sample has a value stored at the corresponding sample location in the output discontinuity volume.

Abstract: A multi-trace geometric attribute of a regularly gridded surface is calculated at multiple scales, wherein, first, a window size is selected. Next, a set of the grid points is defined defining grid cells of the selected window size. Next, the geometric attribute is calculated using the traces at the set of the grid points. Next, the above selecting and calculating steps are repeated for sets of the grid points defining grid cells of different window sizes. Finally, the window size is determined whose calculations best represent the geometric attribute.

Abstract: A method for assessing reliability of a prediction model constructed from N training data attribute vectors and N associated observed values of a specified parameter. Each training data attribute vector includes seismic attributes obtained from seismic data traces located at or near a well and each associated observed value is obtained from well log or core data from the well. A predicted value of the specified parameter is determined for each of the N training data attribute vectors, from the training data attribute vectors and the prediction model. A residual is determined for each of the N training data attribute vectors, as the difference between the associated observed value and the predicted value of the specified parameter for the training data attribute vector. An attribute vector for the designated location is determined.

Abstract: Seismic facies are identified in a volume of seismic data, wherein, first, a plurality of initial textural attributes representative of the volume of seismic data are calculated. Next, a probabilistic neural network is constructed from the calculated initial textural attributes. Then, final textural attributes are calculated throughout the volume of seismic data. Finally, the calculated final textural attributes are classified using the constructed probabilistic neural network.

Abstract: A 2D inversion of true formation resistivity from dual laterolog tool measurements is accomplished using a pre-calculated look-up table. An initial earth model is derived and divided into intervals. A 2D tool response is calculated in each interval using the earth model. Matching is checked between the calculated 2D tool response and the tool measurements. The following steps are iterated until the match is satisfactory. A 1D radial tool response is derived in each interval using the pre-calculated look-up table. Shoulder bed effects are approximated in each interval by subtracting the 1D radial tool response from the 2D tool response. A non-linear least square optimization is applied at boundaries of the intervals and local maximum and minimum values in the intervals to update the earth model.

Abstract: A reactor for subjecting multiple reactant samples to controlled conditions with respect to pressure, temperature, and time. All individual samples in a single test run are exposed to the same temperature and pressure profiles but can be independently and selectively quenched at different times during the test run.

Abstract: A method for attenuating water column reverberations in a dual sensor seismic signal, whereby a pressure signal and a velocity signal are transformed from the time domain to the frequency domain, generating a transformed pressure signal and a transformed velocity signal, respectively. Values for weighting factors K.sub.p and K.sub.v are selected and multiplied times the transformed pressure signal and the transformed velocity signal, respectively, generating a weighted pressure signal and a weighted velocity signal, respectively. The weighted pressure signal and the weighted velocity signal are summed, generating a summed signal. Values for ocean bottom reflectivity R and Z, the frequency domain delay operator for two-way travel time in the water layer, are determined. A weighted inverse Backus filter is calculated and multiplied times the summed signal, generating a filtered signal. The filtered signal is transformed from the frequency domain to the time domain.

Abstract: A method for controlling the position and shape of marine seismic streamer cables, whereby a plurality of real time signals from a marine seismic data acquisition system and a plurality of threshold parameters from an input device are received. The real time signals are compared to the threshold parameters to determine if the streamer cables should be repositioned. The streamer cables are repositioned when the real time signals exceed the threshold parameters.

Abstract: A method of generating an automatic, three-dimensional, locally-unstructured, hybrid grid for geological formations with a sloping fault. The grid generation system replaces the portion of an existing finite-difference grid around the sloping fault with a finite-element grid made of triangular prisms and tetrahedrons. The process comprises decomposing the part of the reservoir around the sloping fault into topologically and geometrically simple volume, face and line components, generating a wire-frame construction of the domain by discretization of the line components, calculating the exact crossings of horizons with the fault, generating a finite-element grid for the face components using an automatic triangulation process, generating a finite-element grid for the volume elements using an automatic tetrahedronization process and assembling the finite-element grid for all volume elements and the finite-difference grid to create a locally-unstructured hybrid grid with enhanced detail around the sloping fault.

Abstract: A marine seismic surveying method recording with a first sensor a first signal indicative of pressure and with a second sensor a second signal indicative of motion, calculating a coupling mechanism filter for the second signal substantially correcting for the imperfect coupling of the second sensor, and applying a filter based on the coupling mechanism filter to at least one of the signals.

Abstract: The present invention is a floatation apparatus with a self-deploying mast for use in a marine towing operation. The invention includes a mast assembly. The mast assembly comprises a shaft adapted to pivotally mount in a storage position on the floatation apparatus, a pair of masts mounted on the shaft forming a structure with front and back sides and dividing the masts into a top section above the shaft and a bottom section below the shaft, pairs of arms and legs projecting perpendicularly from the front of the top section of the masts and from the back of the bottom section of the masts, respectively, a crosspiece connecting the arms to each other and another crosspiece connecting the legs to each other.

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: A marine seismic signal is transformed from time domain into frequency domain and represented by matrix D. The marine data signal is truncated in time, transformed into the frequency domain and represented by matrix D.sub.T. Eigenvalue decomposition D.sub.T =S.multidot..LAMBDA..multidot.S.sup.-1 of matrix D.sub.T is computed. Matrix product D.multidot.S is computed and saved in memory. Matrix inverse S.sup.-1 is computed and saved in memory. An initial estimate of the source wavelet w is made. Source wavelet w is computed by iterating the steps of computing diagonal matrix [I-w.sup.-1 .LAMBDA.], computing matrix inverse [I-w.sup.-1 .LAMBDA.].sup.-1, retrieving matrix product D.multidot.S and matrix inverse S.sup.-1 from memory, and minimizing the total energy in matrix product [D.multidot.S] [I-w.sup.-1 .LAMBDA.].sup.-1 S.sup.-1. Primary matrix P representing the wavefield free of surface multiples is computed by inserting computed value for w into the expression [D.multidot.S] [I-w.sup.-1 .LAMBDA.].sup.-1 S.

Abstract: Pressure and velocity seismic signals are combined, the combined signal is transformed into the frequency domain and multiplied by the inverse Backus operator or the combined signal is convolved with the inverse Backus operator, and an optimization algorithm is utilized to solve for water bottom reflectivity. Pressure and velocity seismic signals are combined, and the combined signal is multiplied by the inverse Backus operator containing the water bottom reflectivity to eliminate first order peg leg multiples.