Abstract: The present invention provides a cementing tool for cementing multiple stages within a well. The assembly includes a housing assembly which defines one or more cementing ports. A first sleeve assembly is retained within the housing and is movable from a first position, where the sleeve covers the port, and thereby precludes fluid flow therethrough, to a second position wherein the sleeve opens the cementing port. The apparatus also includes a second sleeve assembly which is movable from a first position away from the cementing port to a second position wherein the sleeve assembly covers the port. The first sleeve is cooperatively configured with the housing assembly to provide engaging surfaces which resist rotation of the first sleeve relative to the housing. Additionally, the first sleeve and the second sleeve assembly are configured to limit relative rotation when the two pieces are longitudinally adjacent one another.

Abstract: A system and method for reducing pressure in a container pressurized with a fluid provided to the container from a pressurizing fluid source communicate the pressurizing fluid with a receptacle between two valves, close a first one of the valves so that a portion of the pressurizing fluid is contained in the receptacle, and open a second one of the valves so that at least part of the portion of the pressurizing fluid is released from the receptacle.

Abstract: Apparatus and method for detecting the presence of extraneous magnetic fields having a predetermined weak magnitude include a transformer having an excitation winding, an output winding, and a saturable core which will saturate in a magnetic field of a predetermined saturation magnitude. The core is made of amorphous metal alloy and is shaped to cancel the electromagnetic effects of magnetic fields having flux lines which are substantially parallel with respect to the transformer. An excitation circuit is connected to the excitation winding for generating a magnetic field having an excitation magnitude of lesser magnitude than the saturation magnitude of the core. The excitation magnitude and the weak magnitude of the extraneous magnetic fields combine to create a magnetic field of greater magnitude than the saturation magnitude of the core. A detector circuit is connected to the output winding for detecting and indicating saturation of the core.

Abstract: Expandable casing portions are provided, such as casing slip joints or expansion joints, on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. The fracture initiation location may be provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. These slots may be formed by a hydraulic jet which is directed through the opening and then pivoted generally about the point of the opening. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells, but are also useful on vertical wells.

Abstract: A measurement/calibration/probe storage apparatus particularly suitable for measuring pH of fluids and slurries used in the treatment of oil and gas wells. The apparatus includes an enclosure having a conduit for the conveyance of a fluid or slurry therein, a flow chamber being in fluid communication with the conduit, a probe sensor for measuring a preselected attribute of a fluid, or slurry, residing within, or, passing through the flow chamber. The apparatus further includes an electronic processor in electrical communication with the probe sensor for calculating and providing a display of the attribute being measured and a calibration chamber being configured to receive the probe sensor. At least one calibration fluid container being in fluid communication with the calibration chamber is also provided. A control valve is provided for controlling the flow of fluid from each calibration fluid container into the calibration chamber and for controlling the draining of the calibration chamber.

Abstract: A system for sensing the passage of a member past a predetermined location along a tubing disposed in an oil or gas well comprises: a magnet connected to the member, the magnet having a soft body so that the magnet can be drilled out by a drill bit lowered into the well after the member has passed the predetermined location; and a sensor, connected to the outside of the tubing at the predetermined location, for detecting a magnetic field of the magnet as the member with the magnet connected thereto passes the sensor.

Abstract: A cement mixing and pumping simulator comprises actual and virtual equipment. In response to an operator controlling this equipment, signals representing operating characteristics of a cement mixing system realistically represented by the actual and virtual equipment are generated. These signals are communicated for displaying the operating characteristics to the operator so that the operator obtains real-time responses to the operator's control of the actual and virtual equipment.

Abstract: A self-contained multiple channel pressure recorder comprises a single, compact, portable housing containing two quartz pressure transducers and electrical circuits for sensing two pressures communicated into the housing to the pressure transducers, for sensing ambient temperature, and for converting the sensed pressures into electrical signals representing absolute pressure magnitudes compensated both for temperature and calibration effects. The resulting data can be locally displayed through a display mounted on the housing, or the data can be remotely transmitted through an electrical coupling mounted on the housing.

Abstract: Fluid level in a container is determined using a single pressure transducer connected to a portable body. The body contains a computer having a memory in which fluid level-to-fluid volume conversion data are stored for different shapes of containers so that fluid volume can be readily obtained for the shape of the respective container once fluid level is determined. These features allow a single monitoring apparatus to be used for monitoring different types of containers. The apparatus preferably includes a radio so that multiple apparatus can communicate in a system with a central remote operator interface device. Fluid level is determined by dividing a pressure reading from the bottom of the fluid by a fluid density determined from two prior pressure reading taken across a known distance (density equals the difference between the two readings divided by the distance).

Abstract: A method of determining static gel strength of a fluid in a container comprises: commencing relative movement between the fluid in the container and a member disposed in the fluid in the container so that torque is created; stopping the relative movement; and sensing the torque during the time between commencing and stopping the relative movement and detecting the peak torque during such time, wherein the detected peak torque defines the static gel strength of the fluid.

Abstract: A dual crystalline resonator package comprises either (1) two crystalline bodies, in adjoining cavities of which bodies a crystalline temperature resonator and a crystalline reference resonator are respectively connected and which bodies are directly connected together, or (2) such two crystalline bodies in conjunction with a third crystalline body which is connected directly between the two first-mentioned bodies and to opposite sides of which third body the resonators are connected so that the resonators extend therefrom into the cavities of the two first-mentioned bodies. Either of these embodiments can be used for generating temperature data signals in a high pressure, high temperature well wherein the respective embodiment is lowered and exposed to such high pressure and high temperature. A modification of the second embodiment eliminates one of the resonators and the respective body having the cavity into which the eliminated resonator would otherwise extend.

Abstract: A manifold for a front-discharge fluid end reciprocating pump. The manifold comprises tubular portions which are connected to ports on the pump by threaded engagement of a plurality of nuts. The manifold has a center portion and at least one branch portion which intersects the center portion. Another tubular portion having a ported end is in communication with the center and branch portions and provides an outlet for the manifold. At least one nut on the manifold is a standard nut having lugs extending therefrom adjacent to an outer surface of the nut. A special nut is used on at least one of the connections and has lugs extending adjacent to the inner surface thereof. The lugs on the special nut have a longitudinal thickness less than the nuts on the standard nut. In this way, the nuts may be engaged with closely adjacent ports on the pump without interference of the lugs on the nuts with one another.

Abstract: An apparatus and method for sensing temperature in an oil or gas well use an AC-cut temperature crystal connected to a Z-cut crystalline member contained in a crystalline housing that can be subjected to high pressures and temperatures.

Abstract: A tank handling and protection apparatus is particularly suitable for handling tanks carrying liquid additives for oil field servicing operations on offshore vessels. The apparatus includes a frame base and first and second mounting racks attached to the frame base each of those mounting racks having a full-size tank base location defined thereon. Releasable connecting devices are provided for releasably connecting at least one tank to each mounting rack. A protective cage is I0 attached to the frame base and surrounds the tank locations. The protective cage includes removable side walls which allow the tanks to be placed on the frame base with a forklift or the like. The protective cage also has top openings which allow the tanks to be placed on the mounting racks with a sling and crane lifting them through the top openings. The apparatus itself may also be handled with either the forklift or crane and sling.

Abstract: A system and method for mixing cement slurries at an oil or gas well site and for pumping such slurries into the well provide automatic combined and interrelated density and pumping control and selectable sequential control of predetermined mixing and pumping stages. Specific conditions automatically controlled include water rate, water pressure, slurry density, recirculating slurry pressure and downhole pump rate. Each of these conditions is the subject of a respective control loop that operates independently, but under control from a central controller. The central controller generates interrelated inlet water, inlet dry cement and outlet downhole pumping control signals responsive to operated-entered desired operating characteristics.

Abstract: A system and method for reducing pressure in a container pressurized with a fluid provided to the container from a pressurizing fluid source communicate the pressurizing fluid with a receptacle between two valves, close a first one of the valves so that a portion of the pressurizing fluid is contained in the receptacle, and open a second one of the valves so that at least part of the portion of the pressurizing fluid is released from the receptacle.

Abstract: Amplification or generation of very low (and variable) frequency, low voltage, high current bipolar signals useful in electrical borehole telemetry systems is achieved using a duty cycle control device for causing the alternate direct application of a positive voltage and a negative voltage to an integrator. A commutated clamp is connected to the input of the integrator for switchably connecting the integrator directly into a current loop with the load, connected to the output of the integrator, when neither voltage is being applied to the input of the integrator.

Abstract: A concentrator/extractor apparatus for employing solvent to extract a substance from a sample in order to increase the concentration of the substance in less time than prior art apparatuses is disclosed. The disclosed apparatus, and kits including the disclosed apparatus and compatabile components, is provided with a sample containing body in which a hydrophobic membrane is utilized to prevent the sample liquid from migrating to the concentrator portion of the combination extractor/concentrator apparatus. Solvents having densities greater than, or lower than, the sample may be used to process such samples by the disclosed apparatus.

Abstract: The present invention relates generally to laboratory apparatus and more particularly to disposable suspended magnetic stirrers. An apparatus having a stirring vessel closure and a stirring vessel is disclosed. The stirring vessel closure includes a suspended magnetic impeller, the elevation of which is adjustable by a moveable bearing. The invention is particularly suitable for applications in which solids must be suspended in a liquid medium with a minimum of shear forces, such as in the suspension of tissue cell cultures in a growing medium. The disclosed stirring vessel closure has inclined access ports to allow improved pipette accessibility to the interior of the stirring vessel while also providing improved close packing of stirring vessels during usage or storage.

Abstract: A valve includes a seat surrounding an orifice having a concave seating surface and a plug having an annular sealing surface for sealingly contacting the seat. The sealing surface is convex and creates a convex discontinuity in an axially-extending, cross-sectional profile of the plug. The sealing surface retains approximately the same amount of contact area with the seating surface when the plug is misaligned or tilted with respect to the seat as when aligned.