Abstract: A perforating gun and one or more volume-receiving surge canisters can be actuated at a time delay after perforation for creating a dynamic underbalance condition to aid in directing debris out of the perforations and fractures and into the wellbore. A timer and triggering device actuate one or more canisters in parallel or series after a pre-determined time delay or delays which can be related to wellbore conditions following perforation. Use of propellant-type perforating gun further benefits from favorable propellant burn conditions for forming perforations and followed thereafter by a perforation-cleaning underbalance pressure conditions characterized by one or more of an increased rate of change depression of the pressure in the adjacent annulus, a greater magnitude of pressure depression and a longer duration of underbalance.

Abstract: This invention relates to a measurement tool, and in particular to a measurement tool for use in determining the density and/or viscosity of a stationary or moving fluid. The measurement tool has been designed for use in borehole applications during the location and exploitation of oil and gas reserves. The measurement tool has a resilient pipe with a substantially uniform cross-section along its length, and the fluid is located within the pipe. The pipe carries an exciter which is connected to a signal generator, the exciter and signal generator being adapted to impart transverse and/or rotational oscillations to the pipe. Measuring the frequency of the oscillations can be used to determine the density and/or the viscosity of the fluid within the pipe.

Abstract: Apparatus and methods for determining one or more fluid parameters of interest by irradiating fluid with a source of nuclear electromagnetic radiation and subsequently measuring attenuation and absorption properties of the fluid from which parameters of interest are determined. Measurements are made with a formation tester tool comprising preferably two functionally configured flow lines. The source simultaneously irradiates fluid contained in opposing irradiation sections that can be integral sections of each of the two flow lines. A radiation detector is dedicated to each irradiation section and measures radiation attenuation and absorption properties fluid contained within each flow line section. Absolute and relative fluid parameters of interest are determined from the responses of the two radiation detectors.

Abstract: Apparatus and methods for determining borehole diameter and standoff for neutron porosity logging systems. The apparatus comprises an isotopic neutron source, a single epithermal neutron detector and two thermal neutron detectors, where all detectors are at different axial spacings from the neutron source. Thermal neutron porosity is determined from the combined response of the thermal neutron detectors. Epithermal neutron porosity is determined from the response of the single epithermal neutron detector. Embodied as a wireline system, a difference between thermal neutron porosity and epithermal neutron porosity is used to compute a tool standoff, which in turn is used to correct the thermal neutron porosity for effects of standoff. Borehole size measurements are made independently and preferably with a mechanical caliper of a density tool subsection.

Abstract: Memory tool deployment method, system, and apparatus include a landing ring fit on a pipe deployed in a well. A drop-off tool has a landing collar and has a tool string with one or more memory tools. The drop-off tool is connected to a wireline and is deployed through the pipe in the well with the wireline. The drop-off tool is landed on the landing ring on the pipe so that the memory tools extend beyond the pipe. The wireline is released from the drop-off tool and is removed from the pipe so that logging operations can be performed. After logging, the wireline is redeployed in the pipe in the well and is reconnected to the drop-off tool to retrieve the memory tools from the pipe.

Abstract: A monopole acoustic transmitter with at least one disc assembly with a plurality of piezoelectric discs configured to optimized acoustic pressure output within a desired frequency range while meeting physical restrictions of LWD and MWD logging systems. The transmitter is disposed in a recess or “slot” in the perimeter of a logging tool housing to reduce acoustic pressure waves transmitted directly along the tool housing and to optimize acoustic energy transmission into the borehole environs. In order to increase acoustic pressure output at a desired logging frequency range, the plurality of piezoelectric discs in each of at least one disc assembly are connected electrically in parallel and fired simultaneously. The polarity of the discs and the wiring arrangement are such that each disc expands or contracts in a common direction during simultaneous firing by an applied voltage.

Abstract: An acoustic logging system that measures distribution of foam cement and other material in a casing-borehole annulus. The distribution is preferably displayed as map. A borehole tool utilizes at least one acoustic transducer with a known frequency response and mounted on a rotating scanning head that is pointed essentially perpendicular to the borehole wall. The response of the transducer is used to measure an original impedance map of material within the borehole-casing annulus. A fast Fourier transform is used to generate a FFT map from the data comprising the original impedance map. The original impedance map is then combined with the FFT map using logic rules to obtain a final impedance map that is indicative of material within the casing-borehole annulus.

Abstract: This invention relates to a measurement tool and method of use, and in particular to a measurement tool for use in determining a parameter of a stationary or moving fluid. The measurement tool has been designed primarily for use in borehole formation testing. The measurement tool can measure the dielectric constant of a fluid within a pipe or surrounding the tool. The pipe or wall between the tool and the fluid is electrically insulating. The tool has pair of capacitor plates mounted adjacent to the pipe or wall, a signal generator which can deliver an alternating electrical signal to at least one of the capacitor plates, and a detector for measuring a signal dependent upon the electrical capacitance between the capacitor plates. The measurement tool can additionally measure the electrical resistivity of the fluid.

Abstract: A system for measuring pressure in a well borehole using two pressure sensing gauges that are exposed to an area of common pressure. Pressure measurements are made with preferably two pressure gauge assemblies each containing a single pressure sensing gauge. The two pressure gauge assemblies are removably disposed within a receptacle or “pocket” in the outer surface of a wall of a formation tester tool section. When disposed or “side loaded” in the pocket, the gauges within the pair of assemblies are axially aligned and positioned in a plane that is normal to the radius of the formation tester tool section. Both pressure sensing gauges can be connected to respond to the same fluid pressure originating from a probe or port section of a formation tester tool. By disposing the pressure gauge assemblies in a receptacle or “pocket” in the outer surface or wall of a formation tester tool section, the pressure sensing gauges are exposed to wellbore fluids. Pressure sensing gauges are selected to have low mass.

Abstract: In a well control system and method, a tool driver on a toolstring is configured to activate a telemetry tool in response to a predetermined threshold of accelerometer data measured by an accelerometer. For example, the predetermined accelerometer data threshold preferably corresponds to an acceleration level expected while drilling mud is being pumped at a slow pump rate of a well control operation through the drill pipe of the well. When a fluid influx occurs during drilling, the well is shut-in so that the tool driver turns off the telemetry tool. The drill pipe and casing pressures of the shut-in well are obtained. Then, drilling mud having a first weight is pumped into the drill pipe at a slow mud pump rate. Because the tool driver is set to activate the telemetry tool in response to accelerometer data at the slow pump rate, the telemetry tool begins sending downhole pressure data to the surface.

Abstract: A system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying the rotation speed of the drill bit. The steering system comprises a motor disposed in a bent housing subsection and operationally connected to a drill string and to the drill bit. The rotation speed of the drill bit is periodically varied by periodic varying the rotation speed of the motor or by periodic varying the rotation speed of the drill string. Periodic bit speed rotation results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, resulting in borehole deviation. Both the drill string and the drill motor are rotated simultaneously during straight and deviated borehole drilling.

Abstract: An acoustic transmitter with preferably a plurality of piezoelectric plates configured to optimized acoustic pressure output within a desired frequency range while meeting physical restrictions of LWD and MWD logging systems. The transmitter is disposed in a recess in the perimeter of a logging tool housing to reduce acoustic pressure waves transmitted directly along the tool housing and to optimize acoustic energy transmission into the borehole environs. In order to increase acoustic pressure output at a desired logging frequency range, the plurality of piezoelectric plates are connected electrically in parallel and fired simultaneously. The polarity of the plates and the wiring arrangement are such that each plate expands or contracts in a common direction during simultaneous firing by an applied voltage. The desired output frequency is obtained by selectively polarizing and dimensioning the plates within the plate assembly.

Abstract: A borehole logging system for the measure and the telemetry of properties and conditions of a well borehole environs. The system is embodied to measure fluids within the borehole, to measure high resolution images of the wall of the borehole, to transfer of data to and from equipment operating within the borehole environment, and to determine the status of equipment operating within the borehole. The embodiments are based upon emission, measurement and processing of electromagnetic radiation in the near infrared (NIR) region of the radiation spectrum.

Abstract: An acoustic logging system with a borehole tool comprising a transmitter assembly and an axially spaced receiver assembly. The transmitter and receiver assemblies are optionally rotatable with respect to each other, depending upon the embodiment of the logging system. The logging system is designed to measure, among other parameters, the velocity (or slowness) and amplitude of shear wave energy induced by the transmitter assembly within formation penetrated by the borehole. These parameters are extracted from full wave acoustic data responses of receiver elements comprising the receiver assembly, and are measured as a function of azimuth around the borehole. These parameters are subsequently used to determine anisotropic properties of the formation, such as the azimuthal direction of formation fracturing with respect to the well borehole. Optional rotation of the transmitter and receiver assemblies minimizes adverse effects of maintaining calibration and balance of multiple transmitters and receivers.

Abstract: An electrical wireline conveyed baling system for removing large volumes of liquids from a well borehole with a single trip of a bailer tool string. The system also utilizes one or more blow out preventers thereby allowing wireline bailing operations to be carried out while controlling well pressure. A bailer tool string that is conveyed by the wireline comprises a tool head containing a pump, at least one carrier section, and a no-return valve. Once deployed in the borehole, a first signal transmitted via the wireline from the surface activates the pump thereby reducing pressure within the carrier section. A second signal transmitted via the wireline from the surface opens the no-return valve thereby allowing liquid to flow from the borehole into the carrier section. The bailer tool string containing liquid is subsequently retrieved via the wireline thereby removing liquid from the borehole.

Abstract: An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance.

Abstract: In an underbalanced drilling system and method, a change is induced in flowing bottom hole pressure in a wellbore. Data of the surface flow rate of effluent is then measured in response to the induced change. This measured data is obtained using a multi-phase flow meter before a separator of the underbalanced drilling system. Algorithms in computer software analyze the flowing bottomhole pressure and the measured surface flow rate data and determine both permeability and formation pressure for a portion of the wellbore in real-time during the underbalanced drilling operation. Ultimately, portion of the wellbore is characterized with the determined permeability and formation pressure.

Abstract: A formation tester system with a tester tool comprising two or more functionally configured flow lines. The two or more functionally connected flow lines cooperating with one or more pumps and cooperating valves direct fluid to and from various axially disposed sections of the tester tool for analysis, sampling, and optionally ejection into the borehole or into the formation. The functionally connected flow lines extend contiguously through the sections of the tester tool. The functionally configured flow lines, cooperating with the one or more pumps and valves, can also direct fluid to and from various elements within a given tester tool section. Manipulation of fluid flows within the tester tool, as well as analysis, sampling and/or ejection operations, can be varied with the tester tool disposed in the borehole using appropriate commands from the surface of the earth.

Abstract: A system for measuring an acoustic property of material penetrated by a well borehole. The system uses a borehole logging tool comprising preferably one acoustic transmitter and preferably a plurality of acoustic receivers. An independent measurement is used to determine azimuthal orientation of the tool within the borehole. Firings of the transmitter are based upon azimuthal orientation of the tool. Receiver responses resulting from preferably a plurality of transmitter firings per tool revolution are combined to form at least one composite transmitter response. The composite receiver response is compensated for adverse effects of the tool operating eccentered within the borehole.

Abstract: A drilling system utilizing a plurality of independent telemetry systems. The drilling system uses a drill collar as a pressure housing for downhole components of the system. One or more sensors are disposed within the pressure housing. These sensors can be MWD sensors, LWD sensors, or both MWD and LWD sensors. A plurality of independent borehole telemetry systems is used to telemeter sensor response data to the surface of the earth. Each sensor cooperates with a downhole component of at least one of the independent telemetry systems. The plurality of telemetry systems can be of the same type, such as a mud pulse systems. Alternately, the telemetry systems can be of different types including a mud pulse system and an electromagnetic system.