Abstract: In one embodiment the invention comprises a system for generating an image of an Earth formation surrounding a borehole penetrating the formation. Resistivity of the formation is measured using a DC measurement, and conductivity and resistivity of the formations is measured with a time domain signal or AC measurement. Acoustic velocity of the formation is also measured. The DC resistivity measurement, the conductivity measurement made with a time domain electromagnetic signal, the resistivity measurement made with a time domain electromagnetic signal and the acoustic velocity measurements are combined to generate the image of the Earth formation.

Abstract: In a first embodiment the invention comprises a method for cleaning deposits from the interior of a pipe in which a pig is propelled through the pipe by pressure from a fluid mixture of at least one liquid and at least one gas applied to the pig from the rear end of the pig. A portion of the fluid mixture is conducted from the rear of the pig to at least one nozzle on the forward end of said pig and propelled through the nozzle to clean the deposits from the interior of said pipe.

Abstract: The invention in a first embodiment comprises a method of utilizing seismic data attributes for interpreting seismic data from a region of the earth's subsurface, in which values are calculated for a plurality of seismic data attributes of said seismic data, and combinations of said calculated values are generated to develop an indication of shaliness of said region of the earth's subsurface. In another embodiment the invention comprises a device, which is readable by a digital computer, having instructions thereon for defining a process and instructing a computer to perform a process for calculating values for seismic data attributes of said seismic data indicative of thinness of subsurface strata, parallelism of subsurface strata, lateral continuity of subsurface strata and continuity consistency of subsurface strata, and generating combinations of calculated values for said seismic data attributes to generate an indication of shaliness of said region of the earth's subsurface.

Abstract: In one embodiment the invention comprises a method for generating a log of a subsurface formation, in which data from well logging measurements are utilized to derive a relationship between porosity and irreducible water saturation for the formation and the derived relationship between porosity and irreducible water saturation is applied to a porosity log of the subsurface formation to generate a log of irreducible water saturation. In another embodiment the invention comprises a method for calculating a theoretical water saturation log for a subsurface formation which utilizes a relationship based on porosity, irreducible water saturation and height above the petroleum-water contact level.

Abstract: The invention in a first embodiment comprises a system for generating an estimate of lithological characteristics of a region of the earth's subsurface. A correlation is generated between attributes of synthetic seismic data calculated from log data from at least one wellbore penetrating said region and lithological information from said at least one wellbore. The correlation is then applied to recorded seismic data from the region of the earth's subsurface to generate the estimate.

Abstract: In a preferred embodiment the invention comprises a method of processing well log data which includes evaluating the said well log data to identify variations in the well log data which are indicative of thin beds of a selected thickness, and reducing the magnitude in the well log data of the identified variations by a magnitude related to the selected thickness.

Abstract: The invention comprises a method for processing crosswell seismic data from a region of the earth's subsurface generated by transmitting a seismic signal from a plurality of source positions within at least one borehole within said region and detecting said seismic signal at a plurality of receiver positions in at least one borehole within said region. In a preferred embodiment, the seismic data is utilized to develop a model of raypaths traveled by seismic signals from said source positions to said receiver positions, and these raypaths are evaluated to determine if the seismic signal traveling along the raypaths traveled as a headwave for at least a part of the transmission path between the source position and the receiver position. Raypaths along which the seismic signals traveled as headwaves are deleted from the model, and a profile representing a property of the region of the earth's subsurface is then prepared utilizing the residual raypaths.

Abstract: In one embodiment the invention comprises a method of gathering borehole seismic data in which a borehole acoustic instrument is lowered into a borehole in the earth's surface along with a canister positioned about the instrument and a second open bottomed canister positioned below the instrument. The canisters are at least partially filled with gas after the canisters are lowered into borehole. In another embodiment the invention comprises an apparatus for reflecting tube waves in a fluid-filled borehole which includes a canister having a diameter adapted to enable the canister to be deployed within the fluid-filled borehole, and having an open lower end, and an enclosed upper end with an aperture through the upper end adapted for sealing engagement between said upper end and a conduit.

Abstract: The invention is an apparatus for generating a seismic signal in a fluid filled borehole which includes an elongated housing formed from a gas impermeable material and a controlled frequency energy source within said housing. The housing has an external shape which expands and contracts in response to variations in pressure within said housing to enhance the transmission of said seismic signal to the borehole fluid, such as pressure variations resulting from fluid resonance within said housing.

Abstract: A method for acquiring and processing seismic survey data from two or more seismic sources activated simultaneously or nearly simultaneously or for a single source moved to and fired at different locations. In one aspect such a method includes acquiring seismic survey trace data generated by the source or sources, attaching source geometry to the traces, soring the traces according to a common feature thereof, (e.g. to CMP order), interpolating data points for discontinuities on the traces, selecting two halves or two portions slightly more than half of the traces, filtering the trace data for each of the two portions to filter out data related to a second one of the two seismic sources, reducing the filtered trace data to two halves of the data and deleting interpolated data, and then merging the two halves to produce refined useful seismic data related to a first one of the seismic sources.

Abstract: A physical signal is represented by a linear system. The linear system is transformed from the time and space domain to the frequency domain, generating a transformed system. The least significant portions in the transformed system are determined. The least significant portions are deleted from the transformed system, generating a smaller pruned system. The pruned system is solved in the frequency domain, generating a solution. The solution is inverse transformed from the frequency domain to the time and space domain, generating an approximation to the physical signal.

Abstract: This invention provides a method and apparatus for determining position from code modulated, suppressed carrier signals received from satellites, in which a digital composite of the signals received from a plurality of satellites is formed at a first point, the digital composite is processed to measure the carrier phase of the signal from each of the plurality of satellites to derive computer data, and said computer data are combined with data derived from measurements of signals received from the same plurality of satellites at another point, to determine position data.

Abstract: A seismic data acquisition system utilizing a plurality of remote units, each remote unit being coupled to a plurality of receivers placed spaced apart on the earth's surface is provided. The remote units acquire seismic data from their associated receivers in response to a seismic shock wave induced at a selected point on the earth and transmit the acquired seismic data to a recorder over a separate channel associated with each receiver. A signature device located at a known receiver location transmits a data sequence containing an embedded time-invariant code that is unique to the signature device to the recorded during the recording cycle. The signature device data sequence and its location are pre-recorded in the recorder. The recorder utilizing the stored data sequence and the data sequence transmitted by the signature device during the recording cycle to map the seismic data channels corresponding to the locations of their associated receivers.

Abstract: The present invention is a method for improving the estimation of physical properties of a material based on the infrared spectrum of the material and the correlation between directly-measured properties of interest and the infrared spectra of a representative set of calibration specimens of the material. By intentionally introducing spectral distortion such as transmittance shifts, wavelength shifts, absorbance-baseline shifts and absorbance-baseline tilts into the infrared spectra of the representative specimens and then determining the correlation between the distorted spectra and the directly-measured properties before applying the correlation to the infrared spectrum of the sample being analyzed, the correlation is self-compensating for the types of distortion introduced.

Abstract: The invention is a wireline cable head adapted to be used on a wireline tool string which is conveyed into a wellbore by a coiled tubing. The cable head comprises a biased, piston-type check valve which enables fluid circulation from the tubing into the wellbore, but prevents fluid flow from the wellbore into the coiled tubing. The biasing means maintains a minimum differential pressure which must be pumped into the coiled tubing to enable fluid circulation from the coiled tubing into the wellbore. The cable head also comprises a bulkhead for maintaining hydraulic integrity of the cable head after the cable is extracted from the cable head.

Abstract: The invention is a system for determining position by measuring phases of suppressed carrier-waves implicit in radio signals received from earth-orbiting satellites which include receiving the signals from a plurality of satellites simultaneously by means of an omnidirectional antenna, separating the received signals into first and second portions representing different radio-frequency bands and correlating the first portion with the second portion to obtain data representing the phases of the carrier-waves for a plurality of the satellites simultaneously.

Abstract: A method and a system are disclosed for measuring the baseline vector b between a pair of survey marks on the ground by radio interferometry using radio signals broadcast from the earth orbiting satellites of the NAVSTAR Global Positioning System (GPS), the radio signals broadcast by the satellites being double-sideband modulated with their carriers suppressed. An antenna is positioned at each survey mark. The signals received by one antenna during a predetermined time span are separated into upper and lower sideband components. These separate components are filtered, converted to digital form, and then multiplied together. Their product is analyzed digitally by means of correlation with quadrature outputs of a local oscillator to determine the power, and the phase relative to that local oscillator, of the carrier wave that is implicit in the double-sideband signal being received from each satellite. Differences in Doppler shift are utilized to distinguish the carriers of different satellites.

Abstract: The present invention is a method of logging a formation for permeability using a logging tool that is calibrated to dynamically correlate macroscopic porosity measurements to microscopic permeability measurements for the formation. The correlation is determined from hydraulic unit characterization factors which are calculated from parameters of the formation determined in an analysis of core material taken from the hydraulic units determined to be in the geologic units. The hydraulic units are identified from the relationship of direct permeability and porosity measurements with calculated hydraulic unit characterization factors for the formation.

Abstract: An apparatus is provided for determining the acoustic anisotropy of a sample being subjected to simulated in-situ pressures and/or temperatures. A sample of the formation of interest is received by a compliant sleeve disposed in a pressure chamber. The compliant sleeve houses a plurality of transducers which are placed in intimate contact with the sample upon pressurization of the pressure chamber. When the pressure chamber reaches the desired pressure and/or temperature, the transducers are energized. The travel times of the generated acoustic signals through the sample are recorded to determine the anisotropic behavior of the sample. The velocity variations of the sample can indicate the historical principal stress axes of the formation at depth.