Abstract: The present invention is directed to sonic logging while drilling. A transmitter and at least one receiver are mounted on a drill collar for performing sonic investigations of the formation traversed by a borehole. It has been discovered that a drill collar has a natural stop band or notch where acoustic energy propagating in this frequency range is severely attenuated. Thus, to reduce drill collar acoustic coupling, the transmitter is operated within this natural stop band of the drill collar. An imperforate stop band filter is also included between the transmitter and receiver to enhance the natural stop band. The transmitter is mounted transverse to the longitudinal axis of the drill collar, and is preferably mounted within means that reduce drill collar acoustic coupling.

Abstract: A universal sampling device for retrieving samples of high and low viscosity substances at various depths and from specific portions of contained bodies of materials without being completely submerged therein, is disclosed. The sampling device is made of chemically inert material, has manually operable inlet and outlet vent valve means attached to opposite inlet and outlet ends of a relatively long tube into which the sample enters upon opening of the inlet and outlet valve means at the desired point in the substance to be tested. Means are provided for manually closing and opening of the inlet valve means such as pushing and pulling a valve stem by hand into sealingly engagement with an inlet valve body. Another method attaches a valve stem to an adjustable valve control rod extending upwardly through the tube and outlet valve means.

Abstract: The present invention is a disposable bailer having an elongated tube with opposite inlet and outlet ends of the tube, both ends being integral with the tube and tapered; with an inlet valve means, the inlet end of the tube being continuously molded with the tube to form an internal cavity for containing the inlet valve means.

Abstract: The invention is a process of manufacturing an abrasive article with the steps of forming an abrasive article in the unfired state comprising an abrasive, a vitreous bond and a polymer resin wherein the polymer resin has an elastic modulus greater than about 2.0.times.10.sup.9 Pa, a weight gain due to moisture absorption when measured after exposure to a 90.degree. C. temperature and 85% relative humidity for 10 hours of less than about 2 wt % and a weight loss on firing in a nitrogen atmosphere at 5.degree. C. per minute to 550.degree. C. of greater than about 95 wt %, and firing the abrasive article thereby decomposing the polymer resin and creating pores in the abrasive article. The invention further includes the abrasive article formed in the unfired state by the above process.

Abstract: A device for cutting cured and uncured (green) pavement including concrete which is capable of cutting a straight groove without the guidance of an operator. The cutting blade is positioned between the front and rear soft contour wheels in a vertical plane which is side-to-side equi-distant between the wheels. The blade, blade drive motor and the wheel drive motor are arranged so that each wheel carries approximately the same weight to enable the cutting device to move, unassisted, in a straight line.

Abstract: Finished articles made of flexible polyvinyl chloride (PVC) using plastisol technology are improved in terms of resistance to heat and solvents and reduction in plasticizer migration by incorporating into the traditional plastisol ingredients substantial amounts of blocked di- or polyisocyanates and di- or polyols and/or di- or polyamines, which, upon heating react with each other to form a polymer network within the article while the PVC is gelling.

Abstract: A remotely controlled fluid sampling device adapted to take and retrieve samples from any depth or level within a body of fluid comprises an elongated tubular container, the upper outlet end of which is sealingly attached to an end cap. The end cap has a vent passage, a drain passage, a manually operated stop cock for opening and closing off the drain passage, and an eye or hook portion for attaching a support means thereto. A sealed housing is sealingly attached to the opposite inlet end portion of the tubular container and encloses an upper valve chamber with a fluid passage in its outer wall and a lower power chamber separated by an upper end wall in which a valve bore is sealingly engaged by an axially moveable valve stem.

Abstract: A diamond element having good bonding properties and a method for fabricating the diamond element in which a diamond substrate is coated by and bonded to a first layer of chromium carbide, a second layer containing titanium, vanadium, zirconium, niobium, tantalum, iron, cobalt, nickel or copper, is bonded to said first layer, and a third layer of tungsten, or molybdenum deposited by a CVD technique utilizing metal halides, is bonded to said second layer. The second layer functions to protect the chromium carbide layer against attack by halide containing gas during the CVD deposition of the tungsten, or molybdenum.

Abstract: A diamond element having good bonding properties and a method for fabricating the diamond element in which a diamond substrate is coated by and bonded to a first layer of chromium carbide, a second layer containing titanium is bonded to said first layer, and a third layer of tungsten, or molybdenum deposited by a CVD technique utilizing metal halides, is bonded to said second layer. The second layer functions to protect the chromium carbide layer against attack by halide containing gas during the CVD deposition of the tungsten, or molybdenum.

Abstract: The invention relates to a method of determining the porosity of an undergound formation being drilled by a rotating drill bit mounted at the lower end of a drill string. The torque (TOR) and the weight (WOB) applied on the bit when drilling the underground formation are measured; the effect of the geometry of the drill bit on the torque and weight on bit response is determined; the porosity (phi) of the formation being drilled is derived from the measured TOR and WOB taking into account the effect of the geometry of the drill bit. Preferentially, the porosity phi is determined from the following equation:TOR=(k.sub.1 +k.sub.2.phi)WOB.sup.awhere k.sub.1, k.sub.2 and a are parameters characteristic of the geometry of the drill bit.

Abstract: Well logging techniques and apparatus are disclosed for determining formation resistivity at different radial depths of investigation and with greater accuracy than prior techniques, for determining the existence, locations and properties of beds and caves, and for determining changes in the size of a borehole.

Abstract: A method is proposed for better determining the azimuth and inclination of a borehole in which a priori information regarding the magnitude of the earth's gravitational field strength, its magnetic field strength and direction are utilized to constrain the measured components of the earth's gravitational and magnetic field vectors. The constrained fit method adjusts the accelerometer and the magnetometer tri-axis measurements to optimize agreement between the measured data and the a priori magnetic and gravity field strengths and the magnetic dip angle. The adjustment that is selected is that which produces the least increase in the statistical measure .chi..sup.2.

Abstract: Formation Strength and other measurement while drilling parameters are combined to produce a formation volumetric analysis which may including the traditional volumetric components of clay volume, sand volume, total porosity, and water filled porosity. In shaley formations, the volumetric analysis may also include an excess or overpressure porosity. Formation Strength may be derived from measurements of torque and weight on bit and be corrected for such effects as bit dullness, mud weight and hydrostatic pressure balance.

Abstract: A well logging apparatus is disclosed including a cylindrical housing with a transmitting antenna and first and second receiving antennas. The antennas are formed on insulating material in recesses in the housing and have a waterproof rubber covering. The receiving antennas have adjacent compartments containing signal conditioning circuits.

Abstract: A variety of flow and pressure measurements are obtained to characterize the drilling fluids hydraulics system of the borehole drilling process. Notably, a differential pressure measurement which measures the difference between the pressure internal to and external of the drill bit is made close to the drill bit. From this and other measurements are obtained valuable information on whether a change in pressure drop is due to a leak or a lost bit nozzle, on corrections to the downhole weight on bit measurement, on the rate of rotation of a downhole positive displacement drilling motor, on the efficiency of the drilling motor, and on an indication of whether a leak in or a blockage of the drill string has occurred and its location.

Abstract: A method is provided for determining the state of wear of a multicone drill bit. Vibrations generated by the working drill bit are detected and converted into a time oscillatory signal from which a frequency spectrum is derived. The periodicity of the frequency spectrum is extracted. The rate of rotation of at least one cone is determined from the periodicity and the state of wear of the drill bit is derived from the rate of cone rotation. The oscillatory signal represents the variation in amplitude of the vertical or torsional force applied to the drill bit. To extract periodicity, a set of harmonics in the frequency spectrum is given prominence by computing the cepstrum of the frequency spectrum or by obtaining an harmonic-enhanced spectrum. The fundamental frequency in the set of harmonics is determined and the rate of cone rotation is derived from the fundamental frequency.

Abstract: A communications system for providing communication between a downhole well logging apparatus and external equipment in which a portion of the external equipment is placed in an aperature in a side wall of the well logging and electromagnetic signals are exchanged.

Abstract: Methods are disclosed which provide for determining in situ the characteristics of hydrocarbons including oil API gravity in a formation traversed by a borehole. The vanadium content in the formation is determined from a logging tool. The total vanadium content is then systematically separated into an oil vanadium content and a formation matrix or clay vanadium content. From the oil vanadium content and a determination of formation bulk density, porosity and oil saturation, the vanadium concentration of the oil is derived in parts per million, from which the API gravity is determined.

Abstract: A method is proposed for determining the distance from an investigating device to the surface of a medium capable of supporting wave propagation. According to the method, a propagatory wave is generated at a given location along the surface of said medium and spaced laterally therefrom. The propagatory wave is caused to enter the medium and to propagate in the medium. The phase of the propagating signal is detected at a pair of locations respectively spaced longitudinally along the surface of the medium by different distances from the transmitting location. An indication of the lateral spacing between the detecting means and the medium is determined in response to the phase information detected at the pair of locations.

Abstract: The invention in one aspect provides a method of testing drilling mud in use which comprises periodically sampling the circulating mud and analyzing its aqueous filtrate at the rig site by ion chromatography for selected positive and negative ions; one or more other parameters of the sampled mud and/or mud filtrate (e.g. pH, temperature) may also be measured; preferably the composition of the mud filtrate thus monitored is interpreted to indicate downhole interactions, with the composition of the mud supplied to the hole being adjusted to or towards the optimum as drilling proceeds. The invention also provides a method in which the solids of the periodically sampled mud are analyzed at the rig site, e.g. for sorbed ions and/or for cation exchange capacity; the values so obtained are preferably combined with those for the mud filtrate analysis and used in the diagnosis of downhole conditions for adjustment of the composition of freshly supplied mud.