Abstract: An automatic rate matching system is provided such that the delivery of bulk material is matched with the quantity of bulk material required by a process. An optical probe is used which determines the depth of material delivered into a hopper, prior to its retrieval for use in the process. The probe and associated electronic components output a signal to a CPU which then varies the speed of a belt conveyor based upon the depth of material. As the material depth decreases, belt speed is increased. Conversely, as material depth increases, belt speed is decreased. Therefore, the delivery rate of bulk material is matched to the quantity required in a process by varying the speed of the conveyor belt, based upon the depth of material in the hopper.

Abstract: A sequential remote control plug release system allows actuation of plug release plungers and manifold valves associated with a cementing plug container only in a predetermined sequence. With regard to a plug container having two plugs, and thus two plug release plungers, and three manifold valves, the middle and upper manifold valves and the upper plug release plunger can be opened and retracted only in a predetermined sequence. This is implemented through interconnected actuation valves and sequencing valves contained in a housing which can be located remotely from the plug container. An improvement in plug release plungers is also disclosed.

Abstract: A vessel for receiving a test sample of fluid whose water content is to be determined and a thermal neutron sensor are retained in cavities of a biological radioactivity shield. The cavities are lined with a material which blocks external thermal neutrons outside the test sample from being detected by the thermal neutron sensor. Another cavity, having an inner end terminated by the lining material, receives a source of fast neutrons which are to be emitted through the liner into the test sample to become thermal neutrons if they interact with hydrogen within the test sample. The latter thermal neutrons which are backscattered to the sensor are detected, and in response an electrical signal encoded to represent the count of detected thermal neutrons is generated to indicate a measure of the water content of the test sample.

Abstract: A method of tracking fluids flowing along a flow path is disclosed. A flow path is initially described corresponding to the flow path geometry which can be subdivided in real time to correspond to actual fluid volumes which are moved through the flow path. A recursive operation is used to account for moved volumes which exceed segment volumes during one tracking time period. An improved definition of a curved flow path segment is also disclosed. The disclosed method also pertains to maintaining a well pressure balanced by compensating for free fall.

Abstract: A control system and method utilizing a race between two responses to a changing stimulus are disclosed. An example of a changing stimulus is pressure which increases at a decreasing rate of change during a closed-in period of a drill stem test in an oil or gas well. In a preferred embodiment two components are moved in different directions, but in a net first direction, until the rate of change of the pressure is sufficiently low (e.g., near steady state), at which time the rates of movement of the two components produce net movement in a second direction. In a preferred embodiment, the change in direction of the net movement moves a control valve which communicates a pressure control signal for opening a bypass valve to commence a flow period of the drill stem test.

Abstract: A perforating gun is designed to have explosive charges spirally disposed around its circumference in accordance with a displacement angle defined as (m/p)(360.degree.), where p is a whole number greater than 4 and m is a whole number greater than 1 but less than (p-1) and where m/p is an irreducible fraction. A U, or horseshoe, shaped retainer clip holds individual charges in respective holes and cavities of an outer carrier tube and an inner carrier tube to prevent horizontal or transverse movement of each charge and thereby hold it in contact with an axially extending detonator cord.

Abstract: A cutting tool to cut a tubular element in a well is constructed of pellets of less sensitive explosive material detonated by a pellet of a more sensitive explosive material. All the explosive material is packaged in individual packages which qualify for a lower cost, faster, safer transportation classification, but which explosive material is consolidated and assembled at a field location into a cutting tool capable of generating a sufficient force to cut the tubular element. A corresponding method is also disclosed.

Abstract: A mixing apparatus includes a tub, an agitator disposed in the tub, a flow mixer which provides an initial mixture into the tub, and recirculating means for recirculating mixture from the tub through the flow mixer. In a particular embodiment, the flow mixer has a vertical sleeve through which a dry substance is received for mixing with a liquid input through an inlet manifold through which the sleeve extends. The flow mixer also includes a valve comprising an orifice plate, a valve plate and a body in which grooves are formed for forming jets of liquid to engage the dry substance in a downwardly spiraling circulation. Connected to the flow mixer below the valve are at least two recirculation inputs below which a diffuser is adjustably connected.

Abstract: A data signal transmission cable particularly adapted for use in seismic prospecting permits high speed digital data transmission. In a preferred embodiment, the cable includes a transceiver at each end and two repeaters located near the center of the cable for differentiating and retransmitting signals transmitted from respective ends to opposite respective ends. Each repeater is energized from the end from which it receives transmitted data. A preferred method permits communicating seismic data signals over two serial pairs of twisted metallic wires.

Abstract: A sequential remote control plug release system allows actuation of plug release plungers and manifold valves associated with a cementing plug container only in a predetermined sequence. With regard to a plug container having two plugs, and thus two plug release plungers, and three manifold valves, the middle and upper manifold valves and the upper plug release plunger can be opened and retracted only in a predetermined sequence. This is implemented through interconnected actuation valves and sequencing valves contained in a housing which can be located remotely from the plug container. An improvement in plug release plungers is also disclosed.

Abstract: An automatic mixture control apparatus includes a micro-computer-based data acquisition and control device which responds in real time to flowmeter and densimeter signals to control water inlet and bulk cement valves so that a cement slurry is produced at the desired rate and density. The data acquisition and control device is programmed to provide means for computing desired positions for the valves and for computing corrections for the positions. A related automatic mixture control method is also disclosed.

Abstract: A process control system includes a remote control computer connected by two pairs of electrical conductors to a local control computer and a monitor computer. The remote control computer provides a set point from entered control information, the monitor computer provides real time information about an operating characteristic of the process, and the local control computer receives feedback information from a characteristic of the process which is controlled by a control signal provided by the local control computer in response to the set point, the real time information and the feedback information. The monitor computer also provides information about monitored characteristics to the remote control computer. The real time information provided by the monitor computer to the local control computer is transmitted separately from the two pairs of electrical conductors.

Abstract: A resonator assembly comprises a rigid support and a rigid crystal which are rigidly connected along linear segments which have one or more matched thermal characteristics. In a particular embodiment, a thermally matched resonator assembly comprises a Z-cut quartz crystal support, a quartz crystal resonator having an active region and including a crystalline structure oriented relative to X-, Y- and Z-crystallographic axes, which X- and Y-crystallographic axes define an X-Y crystallographic plane; and a rigid connector structure for rigidly connecting the resonator to the support along a segment of a line of a plane parallel to or including the X-Y crystallographic plane, which segment extends across a surface of the resonator and is spaced from the center of the active region of the resonator.

Abstract: A digital filter for use with a randomly generated variable, such as in a radioactive densometer, is provided and includes a microprocessor and timing clock for sampling the random variable over a specific time interval. The microprocessor utilizes a weighting factor based upon a first confidence factor and computes the mean value of a first sample of the random variable and compares the number of standard deviations that a subsequent sample is from the mean value of the previous sample and uses a probability related factor to determine if the subsequent sample represents an actual change in density. Further, the microprocessor uses a second confidence factor in determining the weighting factor which counts the number of consecutive times that the subsequent samples are greater than, or less than the mean value and again determines a probability related factor to determine if a change in density is actually occurring.

Abstract: A core holder for testing core permeability includes a modular sleeve comprising a series of sleeve segments aligned longitudinally. Port rings positioned between the sleeve segments have radial holes to allow conditions within the core-receiving cavity formed by the sleeve segments and the port rings to be monitored from outside the core holder. The port rings and the sleeve segments are disposed within a housing, and spacer rings are received about the sleeve segments to support the sleeve segments and port rings within the housing. Conditions within the modular sleeve may be monitored through instruments connected to holes in the housing communicating with the holes in the port rings.

Abstract: A pumping apparatus comprises a fluid end cylinder carrying a double-acting piston which is reciprocated by a hydraulic servo actuator to provide an expanded flow range ability for metering fluids. The hydraulic servo actuator comprises: a hydraulic cylinder carrying a drive piston connected to the fluid end piston; a servo valve; a position transducer; and a microprocessor-based controller. The controller is programmed to accommodate accleration and deceleration of the extend and retract phases of a pump cycle to maintain constant average flow rate out of the fluid end. A control apparatus for controlling a pump and a related method are also disclosed.

Abstract: A pressure control apparatus suitable for controlling pressures in autoclaves permits a plurality of autoclaves to be selectably pressurized from a single pressurizing circuit. The apparatus can be externally controlled to more efficiently multiplex autoclaves to the pressurizing circuit and to more efficiently implement different pressure schedules for the autoclaves. Once a pressure has been set for an autoclave maintained in communication with the main pressurizing circuit, the apparatus automatically monitors the position of the pump piston and resets it from either of its extreme limits of movement to maintain pressure at a desired set point. Corresponding methods are also disclosed.

Abstract: A cup type formation packer shoe is provided to be used in well cementing operations for cementing either casing or tubing in existing casing in a well bore. This packer shoe includes packer cups which are forced into sealing engagement with the existing casing by the cement being displaced into the annulus between the existing casing and the new casing. Further, the packer cups support the column of cement in the annulus preventing flow downwardly past the packer shoe.

Abstract: A process control system includes a remote control computer located remotely from where the process is to be performed, and the system includes a monitor computer and a local control computer both located where the process is to be performed. The monitor computer and the local control computer are connected to the remote control computer by a common cable including at most two communication channels, each defined in a preferred embodiment by a respective pair of electrical conductors.

Abstract: A sensor apparatus includes a pressure sensor, a reference device and a temperature sensor collocated within a common environment. The reference device and the temperature sensor are constructed to have temperature response times matched to the temperature response time of the pressure sensor to compensate for temperature gradients produced either by external heating or by pressure-volume heating.