Abstract: Method and apparatus are provided for determining the formation pressure. The magnitude of formation pressure may be derived as a function of changes in bottomhole pressure following swabbing the borehole to draw formation fluids into the borehole, monitoring the borehole for influx of formation fluids, determining the reduced pressure due to swabbing, repeating the swabbing and monitoring steps until an influx of formation fluids is detected thereby determining the pressure of the formation.

Abstract: This specification teaches a method of attaching a fluid conducting metal tube (12) a heat dissipating metal fin (14) that includes the following steps. A metal tube (12) is formed having a generally elliptical cross-section having first similarly curved surfaces (22--22) at opposite ends of a major axis thereof and second similarly curved surfaces (24--24) at opposite ends of a minor axis thereof. A heat dissipating metal fin (14) is formed. An elliptically shaped collar (20) is formed on the fin, this collar providing an opening through the fin and being at least about 11/2 times the thickness of the metal forming the fin. The tube is fitted inside the opening of the fin so that areas of these two elements are juxtaposed. The tube is expanded along the major axis so as to bring the first similarly curved surfaces at opposite ends thereof into contact with portions of the collar in juxtaposition therewith.

Abstract: In a borehole telemetry system for acoustically transmitting data over a pipe suspended in a borehole, the level of noise in the data stream is inherently high due to the environment existing in a drilling operation and to the physical characteristics of a drill string. It has been discovered that certain discrete frequency passbands exist in a drill string which permit transmission of an acoustic signal with a minimum level of attenuation. In addition, it is now known that a fine structure exists within these frequency passbands which presents gaps or voids that attenuate the signal at a much higher rate. These gaps are on the order of 20 Hz.By generating an acoustic signal at a precise frequency spectrum within these passbands and then phase shifting the signal before its transmission, the energy spectrum of the transmitted signal is spread out over a sufficient frequency range to bridge these gaps.

Abstract: The method disclosed in this specification is one of reducing the green density of an article cast in a slip casting operation. The article is cast from a casting slip containing silicon metal particles, yttrium containing particles, and a small amount of a fluoride salt which is effective to suppress flocculation of the silicon metal particles by y.sup.+3 ions derived from the yttrium containing particles. The method is characterized by the following step. A small amount of compound which produces a cation which will partly flocculate the particles of silicon metal is added to the casting slip. The small amount of this compound is added so that when the casting slip is slip cast into a casting mold, the partly flocculated particles of silicon will interrupt an otherwise orderly packing of the particles of silicon and particles of yttrium. In this manner, the green density of the slip cast article is reduced and the article may be more easily nitrided.

Abstract: This specification is directed to a rack assembly (40) used in the vacuum brazing of aluminum heat exchangers (10). The rack assembly of this invention includes an upper rack support structure (42) having front (44) and rear (46) facing portions. A pair of rails (48--48) are mounted from the upper rack support structure so that the pair of rails extend from the front facing portion to the rear facing portion thereof in a spaced-apart relationship. The spacing (50) between the pair of rails is sufficient that fluid tubes and fin strips of a heat exchanger can pass therethrough while an upper header member thereof is supported on opposite sides of the pair of rails. An upper locking structure holding device (52) is mounted on the rear facing portion of the pair of rails for holding a locking structure (66) therein. A releasable locating structure holding device (54) is mounted on the front facing portion of the pair of rails for releasably holding a locating structure therein (78).

Abstract: In accordance with an illustrative embodiment of the present invention, a seal or bearing lubricating system adapted for use in a downhole tool such as a drilling motor includes chamber means packed with grease for lubricating said seal and/or bearing, and centrifugal separator means responsive to rotation of a shaft included in said tool for separating and trapping solid particles suspended in the well fluids to prevent contamination of the grease by such solid particles. Pressure equalization across a principal rotating shaft seal also is disclosed.

Abstract: This disclosure is directed to a method of making an infrared reflective glass sheet. The method has the following steps. The glass sheet formed of soda/lime silica glass is selected. The glass sheet is heated to a temperature in a range from 900.degree. to 1100.degree. F. If desired, the sheet glass selected may be selected at the time it is being manufactured in a glass manufacturing operation and it would have upon leaving a process such as a float process a temperature in a range of 900.degree. to 1100.degree. F. An organic/tin ion-containing, chlorine-free compound is applied to a surface of the glass sheet. Application of this compound forms a tin oxide seal coating having a columnar grain microstructure on the surface of the glass sheet. A coating of tin oxide is applied to the tin oxide seal coating. The coating of tin oxide is formed from the decomposition of butyltin trichloride.

Abstract: This disclosure is directed to a method of making an infrared reflective glass sheet. The method has the following steps. The glass sheet formed of soda/lime silica glass is selected. The glass sheet is heated to a temperature in a range from 900.degree. to 1100.degree. F. If desired, the sheet glass selected may be selected at the time it is being manufactured in a glass manufacturing operation and it would have upon leaving a process such as a float process a temperature in a range of 900.degree. to 1100.degree. F. An organic/metallic ion-containing, chlorine-free compound is applied to a surface of the glass sheet. Application of this compound forms a metallic oxide seal coating on the surface of the glass sheet. A coating of tin oxide is applied to the metal oxide seal coating. The coating of tin oxide is formed from the decomposition of butyltin trichloride. The glass sheet is cooled to room temperature after application of the metal oxide seal coating and the tin oxide coating thereon.

Abstract: This specification is directed to a new article of manufacture. In particular, the article is a glass sheet having first and second sides spaced apart in generally parallel planes with a multilayer coating on one of the sides of the glass sheet. The side of the glass sheet having the multilayer coating thereon is designated as the film side of the glass sheet while the other side is designated as the glass side of the glass sheet. The multilayer coating film is a film selected from the group of films consisting of a copper, stainless steel, titanium dioxide multilayer film; a copper, titanium, titanium dioxide multilayer film; and a copper, titanium, titanium nitride multilayer film. The multilayer coating film is characterized, when applied to 6 mm thick clear glass, as having: (1) a film side Y-x-y chromaticity value of reflective color falling within area A of the graph of FIG. 1 of this specification; (2) a glass side Y-x-y chromaticity value of reflective color falling within area B of the graph of FIG.

Abstract: An electrically heated windshield of generally trapezoidal shape has been bus bars of uniform conductivity throughout their length extending in line contact with the upper and lower edges of a continuous uniformly thick trapezoidal-shaped electrically conductive coating provided on the windshield surface for deicing and defrosting the windshield. The line of contact of the upper bus bar with the conductive coating has a length generally equal to the entire effective length of the upper edge of the conductive coating. The lower bus bar is symetrically located along the lower edge of the conductive coating and has a line of contact length equal to the sum of the length of the upper bus bar plus generally about one-half the difference between the entire effective length of the lower edge of the conductive coating minus the length of the line of contact of the upper bus bar.

Abstract: This specification discloses a method of making a titanium dioxide element (20) which can be used as an oxygen sensing element. The method involves the selection of at least a pair of electrically conductive leads (12--12) which resist oxidation at high temperatures. The leads are placed in a position generally close to one another with a slurry bridgeable space therebetween. Slurry (14) is applied to the pair of spaced leads. The slurry contains titanium dioxide, an organic heat decomposable binder, and an organic solvent. The slurry is one that when applied to the pair of spaced leads the surface tension of the slurry draws it into a compact generally spherical shape about the pair of spaced leads. The slurry is dried, heated and sintered so that the titanium dioxide particles contained in the slurry are sintering together to form a titanium dioxide oxygen sensing element bridging the bridgeable space between the pair of spaced leads.

Abstract: A down-hole signal transmitter for a mud pulse telemetry system comprises a flow constrictor defining a throttle orifice for the mud flow, a throttling member displaceable to vary the throughflow cross-section of the throttle orifice, and a pump for displacing the throttling member against the mud flow in order to modulate the mud flow. The displacement of the throttling member is controlled by a hydraulic amplifier, comprising a main pressure relief valve and a subsidiary control valve, and a solenoid to which the output signal of a measuring instrument is supplied. When the main valve is close, the pump displaces a ram, coupled to the throttling member, upwardly.

Abstract: Method and apparatus for measuring the flow velocity of drilling mud returning from the annulus of a borehole. At least two parametric acoustic pulse transducers are longitudinally disposed with respect to a conduit with a pair of acoustic receivers positioned therebetween. The transducers each generate strong, focused acoustic waves comprised of combined dual frequencies directed at the center of the conduit area in which fluid flow is to be measured. The transducers are actuated alternately and produce time variant signals permitting measurement of fluid flow by employing the Doppler effect on the parametric secondary acoustic pulses. The utilization of combined dual frequency acoustic transducers provides a primary signal having sufficient strength to produce a non-linear response in the liquid and produce secondary, low frequency wave propagation directly from within the mud itself. The low frequency waves enhance wave propagation through gas cut muds and enhance signal recognition in the receivers.

Abstract: A drilling mud flow rate detector, including a sub adapted for being positioned in the drill string, having a sonic signal generator located near the center of the sub in both the incoming mud flow path and the return mud flow path. A set of sonic signal receivers is located at both ends of the sub in both the mud input flow path and the mud return flow path and corresponding sets of sonic signal transmitters are located near the center of the sub. The distance between the transmitting transducers at the center of the sub and the receiving transducers located at each end of the sub are equal so that under a condition of no mud flow, the sonic signals arrive at each end of the sub simultaneously. During mud flow, "doppler effect" will produce phase shifts in the sonic signals which are proportional to the direction and the rate of mud flow. Signals received by the receiving transducers are processed to produce an input mud flow rate signal and an output mud flow rate signal which are then compared.

Abstract: A circuit (10) for obtaining a voltage reading (V.sub.o) from a sensing element is characterized by the following structure. A first circuit (12) connects a first end (14) of a voltage source (16) to a first end (18) of a resistance heater (20). A second circuit (22) connects a second end (24) of the voltage source to a second end (26) of the resistance heater. A sensing element (28) has two leads (30,32). A third circuit (34) connects lead (30) of the sensing element to an external circuit (36). A load resistor (40) is coupled between the second circuit and the third circuit. An interconnecting circuit (42) couples lead (32) of the sensing element intermediate the resistance heater. The electrical resistance of resistance heater is substantially less than the electrical resistance of the sensing element.

Abstract: This specification is directed to a method of making a compound selected from the group consisting of birnessite compounds of the formula Bi.sub.x Mn.sub.y O.sub.2y+1.5x.zH.sub.2 O, wherein the y/x ratio is in a range of from about 7 to about 18 and the z/y ratio is in a range of from about 0.5 to about 0.6, Pb.sub.x Mn.sub.y O.sub.2y+x.zH.sub.2 O, wherein the y/x ratio is in a range of from about 6 to about 10 and the z/y ratio is in a range of from about 0.5 to about 0.6, and manganese oxide compounds containing both of these compounds. The method is characterized by the following steps. A solution is formed by mixing Mn(NO.sub.3).sub.2 with a nitrate of bismuth or lead or mixtures thereof. The solution is maintained at a relatively constant temperature and NaOH is added to the solution, whereby Mn(OH).sub.2 and a hydroxide of bismuth or lead or mixtures thereof form a suspension. While the suspension is being agitated, oxygen is passed through the suspension, whereby the Mn(OH).sub.

Abstract: A method of making a silicon metal containing article is characterized in the following steps. A water vehicle first slurry is formed which contains silicon metal particles, this first slurry being substantially free of ions which would cause a flocculation of the silicon metal particles. An organic vehicle based second slurry is formed which contains a compound which has an ion which would cause flocculation of silicon metal particles contained in a water vehicle slurry. The organic vehicle of said second slurry, however, is effective to suppress formation of ions by the ion forming compound. The first and the second slurries are added to form a castable silicon metal particle containing slurry in which the compound contained in the organic vehicle can form ions when in contact with the water vehicle. The castable silicon metal particle containing slurry is introduced into a casting mold.

Abstract: An improved temperature sensing structure (40) for use in a glass bending furnace (10) is made of the following. A thermocouple element (42) is provided which has a pair of thermocouple leads (44) and (46) terminating in a junction (48) which defines a planar loop portion of the thermocouple element. Mounting structure (50) is provided for mounting the pair of thermocouple leads with the planar loop portion thereof projecting outwardly from a free end. A protection tube has an elongated portion (54) in surrounding relationship to the mounting structure which mounts the pair of thermocouple leads and a free end portion (56) which in part surrounds a significant portion of the planar loop portion of the thermocouple element. The surrounding part of the free end portion of the protection tube is positioned so that the planar loop portion of the thermocouple element lies in a plane in facing relationship to an unsurrounding part of the free end portion of the protection tube.

Abstract: A device for determining the stuck point of a drill pipe in a borehole consisting of two relatively movable sections, anchoring means for each section, a sensing means for detecting relative movement of the two sections and producing an inductance representative of the movement. The inductance is transformed into a frequency modulated signal which is transmitted to the surface and converted from a non-linear direct current voltage representation of relative movement to a linear direct current voltage.

Abstract: When surveying a borehole using an instrument responsive to the earth's magnetic field, a length of non-magnetic drill collar is necessary to house means for measuring the magnetic field in the borehole perpendicular to the direction of the borehole axis. The instrument determines the inclination angle and the highside angle from the gravitation measurements, with these measurements and the magnetic measurements, the azimuth angle is determined. Using the method of this invention a minimum length of non-magnetic material necessary for an accurate measurement may be calculated and used.