Matches 401 - 434 out of 434 < 1 2 3 4 5 6 7 8 9


Match Document Document Title
4297699 Radar drill guidance system  
The present invention comprises a short-pulse radar guidance tool which determines borehole-to-roof and borehole-to-floor distances along a coal seam by measuring the travel times of...
4266608 Method for detecting underground conditions  
Disclosed is a method for detecting the flame front during the in situ combustion of a subterranean carbonaceous stratum which involves providing one or more radio transmitters below the surface...
4209747 Apparatus and method for determination of subsurface permittivity and conductivity  
The disclosure is directed to an apparatus and method for determining dielectric constant and/or conductivity of earth formations surrounding a borehole. Electromagnetic energy is generated at a...
4161687 Method for locating underground anomalies by diffraction of electromagnetic waves passing between spaced boreholes  
Underground anomalies or discontinuities, such as holes, tunnels, and caverns, are located by lowering an electromagnetic signal transmitting antenna down one borehole and a receiving antenna down...
4158165 Apparatus and method for determining subsurface formation properties  
The disclosure is directed to an apparatus and method for determining the water-filled porosity of formations surrounding a borehole. Alternatively, where porosity is known from other logging...
4156177 Apparatus and method for determination of free fluid in subsurface formations  
The disclosure is directed to an apparatus and method for determining the bound-water-filled porosity of formations surrounding a borehole. Bound-water-filled porosity is the fraction of the...
4092583 Apparatus and method for determination of subsurface porosity utilizing microwave electromagnetic energy  
The disclosure is directed to an apparatus and method for determining the water-filled porosity of formations surrounding a borehole. Means are provided for deriving a first quantity which is a...
4077003 Microwave method and apparatus utilizing dielectric loss factor measurements for determination of adsorbed fluid in subsurface formations surrounding a borehole  
An apparatus and method for determining the amount of adsorbed fluid in formations surrounding a borehole. In accordance with the present invention, means are provided for deriving a first...
4063151 Microwave apparatus and method for determination of adsorbed fluid in subsurface formations surrounding a borehole  
An apparatus and method for determining the amount of adsorbed fluid in formations surrounding a borehole. In accordance with the present invention, means are provided for deriving a first...
4052662 Method and apparatus for investigating earth formations utilizing microwave electromagnetic energy  
A method and apparatus for investigating earth formations surrounding a borehole by injecting microwave electromagnetic energy into the formations and then taking measurements which relate to the...
4045724 Electromagnetic wave method for mapping subterranean earth formations  
The present invention is directed to a method for remotely mapping subterranean coal beds prior to and during in situ gasification operations. This method is achieved by emplacing highly...
3984758 Method and apparatus for geophysical exploration in drill holes by means of very low frequency waves  
A method and apparatus for geophysical exploration which does not require the installation of a low frequency transmission source in the proximity of the drill hole.A surface pick-up 3 detects the...
3944910 Method and apparatus utilizing microwave electromagnetic energy for investigating earth formations  
A method and apparatus for investigating earth formations surrounding a borehole by injecting microwave electromagnetic energy into the formations and then taking measurements which relate to the...
3849721 MICROWAVE LOGGING APPARATUS HAVING DUAL PROCESSING CHANNELS  
An apparatus for investigating, with propagating microwave electromagnetic energy, earth formations surrounding a borehole. In accordance with the invention there are provided first and second...
3690164 PROCESS FOR PROSPECTING OF THE GROUND LAYERS SURROUNDING A BOREHOLE  
To determine physical characteristics of successive ground strata, signals are transmitted from successive depth locations in a borehole and received at a surface location spaced from the location...
3582766 PASSIVELY CONTROLLED DUPLEXER-COUPLER APPLIED TO A HELICAL ANTENNA FOR USE IN A BOREHOLE PENETRATING AN EARTH FORMATION  
A passively controlled duplexer-coupler is applied to a helical antenna for use in a borehole penetrating an earth formation to produce cross-polarized transmitting and receiving characteristics.
3551797 HIGH FREQUENCY ELECTROMAGNETIC WELL LOGGING METHODS AND APPARATUS  
3479581 VERTICAL RESISTIVITY LOGGING BY MEASURING THE ELECTRIC FIELD CREATED BY A TIME-VARYING MAGNETIC FIELD  
3449657 HELICAL ANTENNA FOR IRRADIATING AN EARTH FORMATION PENETRATED BY A BOREHOLE AND METHOD OF USING SAME  
3440523 METHOD AND APPARATUS FOR ELECTROMAGNETIC DETERMINATION OF THE POSITION OF BOUNDARIES OF AND DISCONTINUITIES IN A GEOLOGICAL FORMATION  
3412815 Electromagnetic radiation method for guiding the drilling of oil wells after the borehole has entered a massive earth formation of chemically deposited material, by a mistake, accident, or the like  
3412323 Subsurface electromagnetic irradiation ranging method for locating fractures within formations  
3412322 Discontinuity location by frequency modulation electromagnetic energy  
3412321 Oil-water contact location with frequency modulated electromagnetic energy  
3403328 High-strength logging tool housing having a compressibly stressed side wall  
3398356 Method utilizing a pair of subsurface antennas for determining the physical properties effecting radio energy propagation through earth  
3391334 Resistivity logging based upon electromagnetic field measurements carried out with three vertically spaced detectors  
3383586 Power supply including non-conductive mechanical transmission means for radio frequency exploration unit  
3378097 Transducer rotating mechanism for borehole logging tools  
3350634 Electromagnetic investigation for salt webs interconnecting spaced salt domes  
3286163 Method for mapping a salt dome at depth by measuring the travel time of electromagnetic energy emitted from a borehole drilled within the salt dome  
3213358 Method and apparatus for generating and detecting shear waves in earth formations  
3114875 Microwave device for testing formations surrounding a borehole having means for measuring the standing wave ratio of energy incident to and reflected from the formations  
2992325 Earth signal transmission system  

Matches 401 - 434 out of 434 < 1 2 3 4 5 6 7 8 9