Abstract: Disclosed is a method of and an apparatus for measuring the thickness of an object, usually a metal strip, by using a radiation beam and digital techniques and, more generally, a method of linearization of an exponential function which can be advantageously implemented by digital techniques. First, a counter is preset to a count corresponding to a predetermined magnitude of a value to be linearized. Then, a sequence of pulses whose number is representative of the value to be linearized is generated. The pulses of this sequence are counted so as to generate a signal each time the number of pulses counted corresponds to a standard value unit. Each signal so generated is used to modify by a predetermined count the count of the preset counter whereby, at the end of the sequence, the contents of the preset counter is representative of the value to be linearized.

Abstract: Digital calculating apparatus, which is particularly suitable for linearizing a digitized output signal produced by a non-linear transducer such as a thermocouple, comprises a store connected in a recirculating loop including combined adder and subtractor circuit, means for changing a number entered in the store to a predetermined target value by a linear or an exponential progression involving groups of N adding or subtracting-cycles, means for counting and storing the numbers of groups of cycles required to achieve the target value, and means for entering another number in the store and subjecting it to the same numbers of groups of M adding or substracting cycles, where M .ltoreq. N, to produce the required answer. For linearizing the digitized output signal x from a thermocouple, where x is given by T = a.sub.o + a.sub.1 x + a.sub.2 x.sup.2 + . . . ta.sub.n x.sup.

Abstract: In the representative embodiment of the new and improved apparatus for testing earth formations disclosed herein, fluid-admitting means are sealingly engaged with a potentially-producible formation and a selectively-movable chamber is expanded to draw mudcake and other plugging materials from the isolated face of the formation into the receiving chamber. Thereafter, the chamber is shifted to communicate the screened entry port of the fluid-admitting means with the isolated formation so as to retard or prevent the erosion of loose formation materials as the formation is tested. When the testing is completed, the chamber is cleared and returned to its initial port-closing position and the fluid-admitting means disengaged to ready the apparatus for subsequent operations.

Abstract: In the representative embodiment of the present invention disclosed herein, shaped charges adapted for installation in a typical end-loaded carrier are respectively provided with a domed annular retainer member of a thin, but substantially rigid and stiff, material which is coaxially disposed over the forward end of each charge. A smaller-diameter externally-tapered sleeve of a somewhat yieldable or deformable material is cooperatively arranged for positioning on each domed retainer member once its associated shaped charge is installed in the carrier facing and aligned with a lateral port therein. Then, as a port plug having an internally-tapered recess is installed in the port and telescopically forced over the sleeve, the forward portion of the retainer sleeve will be laterally compressed for securing the shaped charge in position with little or no inward or axial deflection of the domed retainer.

Abstract: In accordance with an illustrative embodiment of the present invention as disclosed herein, a wireline pulling and running tool can be preset at the surface by simple adjustment for functioning as either a pulling or a running tool, and for release from an associated hanger mandrel by jarring either upwardly or downwardly. A tubular support that carries pivotally mounted gripping elements which are yieldably urged toward disengaged position, has a control body movably mounted therein. The control body has a plurality of sets of circumferentially spaced recess means than can be selectively aligned with the gripping members to enable release thereof in response to vertical movement of the control body from an initial upper or lower position where the body is releasably fixed to the support by a shear pin.

Abstract: In the representative embodiments of the present invention described herein, a drilling mud is circulated through a drill string at a sufficient rate to effectively operate an impeller-driven electrical generator arranged on a tool coupled in the drill string for supplying power to downhole electrical circuits and one or more downhole condition-measuring devices on the tool. By selectively controlling the flow of drilling mud past the impeller in accordance with the conditions being monitored by the condition-measuring devices, data-encoded acoustic signals are produced in the circulating fluid and transmitted to the surface for detecting and decoding as power is simultaneously supplied to the downhole system by the generator.

Abstract: In accordance with illustrative embodiments of the present invention disclosed herein, a shock absorber adapted to be incorporated in a drill string includes axially splined housing and mandrel members that enclose a resilient structure which absorbs longitudinal vibrations and shock loads and otherwise attenuates exciting forces generated by the drill bit. The resilient structure comprises inner and outer cylindrical torsion tube springs providing a low spring rate.

Abstract: This invention relates to electronic analogue to digital converters of the integrating type wherein a capacitor is successively charged by an input signal and discharged by a reference signal, the time required for discharge serving as a measure of the amplitude of the input signal.The invention provides a converter wherein the integrator has differential inputs and the control means applies successively the input signal and the reference signal to the same input of the integrator if these signals are of different polarity, but successively to different ones of the differential inputs if input signal and reference signal are of the same polarity.The invention has application in measuring positive or negative input signals whilst employing a single principal reference signal and may be used advantageously in digital voltmeters for making d.c. measurements in the presence of interference.

Abstract: The crankshaft bears a mark which passes in front of a sensor. When the crankshaft is rotated as the engine turns, the sensor delivers a squarewave signal when this mark passes in front of it. The mark and the sensor are positioned with respect to each other such that when the end of the mark passes in front of the sensor the piston is in a given low position and moves up toward the spark plug and such that when the other end of the mark passes in front of the sensor, the piston has substantially reached its maximum stroke within the cylinder in the vicinity of the spark plug, i.e. when it produces the maximum compression of the combustion gases located in the cylinder. The output of the sensor is connected to the input of a reset circuit of a counter and to the input of a count start and stop circuit of this counter and also to the input of a transfer control circuit.

Abstract: The analogue to digital converter is of the bipolar mark-space type and includes an integrator for integrating the analogue input signal to be converted. A square wave generator is connected to the input of the integrator so as to superimpose a triangular periodic signal on the output signal produced by the integrator.First and second level detectors are connected to compare the output signal from the integrator with first and second detector levels respectively to produce first and second control signals respectively when the magnitude of the output signal from the integrator exceeds the first level and falls below the second level respectively. Switch means responsive to the first and second control signals are provided to respectively apply first and second reference signals. The conversion interval is set equal in duration to the duration of an integral number of cycles of the periodic triangular signal.

Abstract: Electronic analogue to digital converters of the integrating type wherein a capacitor is successively charged by an input signal and discharged by a reference signal, the time required for discharge serving as a measure of the amplitude of the input signal.

Abstract: In the representative embodiment of the present invention disclosed herein, new and improved pipe-inspection apparatus for examining oilfield piping includes, along with other flaw-inspection devices, a flux-leakage inspection device uniquely arranged for detecting minute magnetic-flux anomalies which are indicative of metal defects such as cracks, pits, holes and the like. In contrast, however, to the prior-art high-intensity electromagnetizers typically having cores of minimum magnetic reluctance, the unique pipe-inspection apparatus of the present invention instead employs an electromagnetizer having a core of a substantial length and minimum cross-sectional area to specifically make its reluctance relatively large in relation to the combined magnetic reluctances of the magnetized piping wall and the annular clearances between the piping wall and the magnetizer pole pieces.

Abstract: In accordance with an illustrative embodiment of the present invention, a hollow mandrel mounted in a production string has an eccentrically disposed, lateral recess adapted to receive a measuring instrument. A plug-in contact assembly is located at the lower end of the recess and is connected to an electric cable which is fixed to the outside of the production string. The measuring instrument includes a receptacle assembly on its lower end which is fitted onto the contact assembly during emplacement of the instrument in the recess, thereby to provide in combination with the cable an insulated electric connection between the measuring instrument and the surface. The measuring instrument can be placed into, or removed from, the recess as desired, for example by means of conventional running and pulling tools that are lowered into the production string at the end of a wireline.

Abstract: Artificial lift apparatus for use in a well having an outer pipe string for flow of a first fluid and an inner pipe string for flow of a second fluid. The apparatus may comprise a tubular receiver for connection in the inner pipe string and having ports for providing communication between the inner and outer pipe string. The receiver may include an inner tubular member and a concentrically surrounding outer tubular member defining an annular passageway therebetween through which at least a portion of the first fluid flow may pass. The apparatus may also include a well tool adapted for movement through the inner pipe string for engagement with the receiver inner tubular member and being provided with at least one valve for controlling fluid flow between the inner and outer pipe strings through the ports.

Abstract: A multiband radio transceiver capable of operating in the CW, USB, and LSB modes is disclosed including a dual conversion receiver having digital apparatus for displaying the carrier frequency of the signal to which the transceiver is tuned. A mixer is included for deriving a premix signal related in frequency to the frequencies of two local oscillator signals. The display apparatus includes a counter for counting the frequency of the premix signal. In order to provide a direct display of the tuned signal carrier frequency, a number which varies according to the intermediate frequency of the signal to which the transceiver is tuned is loaded into the counter prior to occurrence of the counting operation. Apparatus is provided for loading the proper number into the counter in accord with the operating mode of the transceiver.

Abstract: An anchoring system for a floating drilling vessel or the like comprises a wire rope having one end attached to an anchor and the other end secured to the drilling vessel. The secured end has attached thereto a floating tag line with a length greater than the location water depth, making it possible to easily recover a wire rope that is cast-off in the event the vessel is required to quickly leave its location, for example, in an emergency.

Abstract: In the representative embodiment of the present invention disclosed herein, a well bore flowmeter is provided with a fluid-driven spinner which is uniquely mounted on the closed end of a hollow shaft that is coaxially disposed over a spindle and rotatably journalled thereon by one or more bearings located in the enclosed annular chamber defined between the shaft and the spindle. To protect the bearings, the chamber is filled with a lubricant and the chamber is communicated with the exterior of the flowmeter only by way of a multi-directional passage which effectively serves to block the entry of well bore debris as the flowmeter is operating. As a further protection for the bearings, one or more valve members are also preferably provided for blocking communication with the bearing chamber as the flowmeter is moved into and out of a well bore. These valve members are preferably actuated by the extension and retraction of a centralizer provided for centering the flowmeter as it is operated in a well bore.

Abstract: In the representative embodiment of the new and improved formation-testing apparatus disclosed herein, a wall-engaging sealing pad is arranged around the forward end of a normally open tubular probe which is adapted to be placed in communication with an adjacent earth formation and carries an extendible filter probe coaxially supported therein by a tubular valve member. If a formation being tested is relatively incompetent, the filter probe will be advanced into the formation without allowing further erosion of loose formation materials with the valve member acting to block communication through the outer probe. Alternatively, should a formation being tested be relatively competent, the filter probe will remain in its normal retracted position and the valve member will cooperatively block communication through the filter probe and instead provide an unrestricted flow passage through the outer probe to a sample-collecting system on the apparatus.

Abstract: New and improved methods and apparatus exemplifying the present invention are disclosed herein for measuring the changes in total elongation of a drill string due to variations in the tensional forces acting thereon during a typical well drilling operation on a floating platform, measuring the changes in the total length of the drill string as it is moved into and out of the borehole from the platform, and measuring the changes in the position of the platform in relation to the upper end of the drill string which are caused by wave motion. Thereafter, these measurments are uniquely combined for producing an output signal which is representative of the changes in the borehole depth. The combined measurements are also converted for producing another output signal which is representative of the actual rate of penetration of a drill bit coupled to the drill string.

Abstract: A ramp type analogue to digital converter including an integrating circuit the output of which is first set to a level dependent upon the magnitude of an analogue input voltage to be converted. A reference signal is then applied to ramp down the integrator output level to a datum level and the conversion is effected by counting clock pulses while the integrator output is ramping down to datum level. The magnitude of the reference signal and the numerical weighting of the clock pulses being counted are scaled down by a common factor when the ramp reaches a value close to the datum level so that the slope of the ram is reduced and the resolution of conversion is increased as it approaches datum. Thus, compared with a ramp type digital voltmeter having a constant slope discharge ramp and a given resolution, the discharge time is reduced for the same resolution of conversions.