Abstract: A method and apparatus for collection of pore water samples from a subsurface geologic formation, especially a vadose zone formation having high capillary tension. The method consists of injection of a fluid with known tracer concentrations therein into the formation. The injected displacement fluid develops a wetting front which carries with it the ambient pore water. The mixture of pore water and tracer-bearing displacement fluid is absorbed by a collection system, such as an absorbent member or pumping system. The injection and collection system are attached to a sealing borehole liner for emplacement in a borehole in the formation, and for other functions. Water samples collected in the collector system may be recovered by inversion of the liner, or alternatively by pumping. Samples thus removed from the borehole may be evaluated for chemicals, such as contaminants. The use of the tracer permits pore water characteristics to be distinguished from the motivating displacement fluid.

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: Transducer apparatus for subsurface use. A tubular configured for subsurface disposal is equipped with a cylindrical transducer module formed of a non-conductive material. The module is mounted to surround a section of the tubular and includes a transducer element disposed thereon such that only a surface of the element is exposed along the exterior of the module body. The transducer element is linked to a lead routed through the cylindrical body to exit near the inner bore of the body. The ends of the cylindrical body are covered with a material to form a hydraulic seal. A method for constructing the transducer apparatus.

Abstract: A method for determining a property of earth formations surrounding a borehole includes the following steps: deriving a fluid sample downhole in the borehole, subjecting the sample while downhole to a magnetic field; measuring a magneto-optical shift of a beam of electromagnetic radiation passed through the sample, and determining the property from the measured magneto-optical shift.

Abstract: A device for monitoring the position of an oil/water contact (OWC, 22) between an oil-continuous fluid (2o) overlying a water-continuous fluid (2w) inside a casing pipe (7). The device includes a transmitter (5) for a generating an electromagnetic signal (ST) and the transmitter (5) is provided with electrical energy (GT) from a voltage signal generator (G). The transmitter (5) is arranged inside the casing pipe (7) in the oil-continuous fluid (2o) and above the oil-water contact (22). The electromagnetic wave signal (ST) partly propagates downwards from the transmitter (5), is partly reflected from the oil-water contact (22), and is partly reflected by the end of the casing, giving rise to an upward propagating, reflected electro-magnetic signal (SR).

Abstract: A sensor system includes a carrier configured for a specific application; an electronics module mountable in a number of individual carriers; a feedthrough mountable in a number of individual carriers and in operable communication with the interface; a sensor mounting mountable in a number of individual carriers and in operable communication with the feedthrough; and a sensor array articulated to the sensor mounting.

Abstract: Measurements made with an induction logging tool are processed to provide a resistivity model of fluid invasion of the formation. Up to five zones can be determined over a radial distance of about 0.6 m. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A sensor for performing micro-conductivity measurements during well logging measurements in a borehole includes a magnetic core having a conductive insert wherein windings are driven with alternating current. Some embodiments include a sensor further having a conductive case. Various aspects of the sensor, such as dimensions and conductive properties of fabrication materials are selected to maximize performance of the sensor. Methods for using the sensor call for, among other things, placing the sensor in a well logging tool, and placing the tool in a well bore. A substantial focusing of the magnetic field on the wall of the borehole is achieved and provides for high quality data.

Abstract: For use in logging downhole in an earth borehole, a method for determining a characteristic of oil that may be present in a downhole measurement region, includes the following steps: providing a plurality of crude oil samples; determining the viscosities of the crude oil samples; performing test measurements, using a predetermined operating mode, on media including the crude oil samples to obtain test data; applying a test processing procedure to the test data to obtain an output test parameter relating to the test data and the predetermined operating mode; deriving, for the plurality of crude oil samples, a correlation relating the output test parameter to the viscosities of the crude oil samples; performing downhole measurements in the measurement region with a logging device, operated with substantially the predetermined operating mode, to obtain logging data, and applying a measurement processing procedure to the logging data to obtain an output logging parameter; and determining the oil characteristic us

Abstract: A method for determining a property of earth formations surrounding a borehole includes the following steps: deriving a fluid sample downhole in the borehole, subjecting the sample while downhole to a magnetic field; measuring a magneto-optical shift of a beam of electromagnetic radiation passed through the sample, and determining the property from the measured magneto-optical shift.

Abstract: A probe 1 for measuring the electromagnetic properties of a down-hole material MC, GF, DM of a well-bore WB comprises a metallic pad 2 in contact with the down-hole material. The pad 2 further comprises an open-ended coaxial wire 4 coupled to an electronic circuit 3. The open-ended coaxial wire 4 comprises an inner conductor 4A sunk in an insulator 4B and is positioned sensibly perpendicularly to the well-bore wall. The electronic circuit 3 is able to send a high-frequency input signal into the open-ended coaxial wire 4 and to determine a reflection coefficient based on a high-frequency output signal reflected by the open-ended coaxial wire 4.

Abstract: Earth formations are characterized by using an array of electrodes which can measure streaming potentials in the formation, and by interpreting the data obtained by the electrodes. The electrodes are placed on a wireline tool, a LWD tool, or in a fixed manner about a completed wellbore. The measured streaming potentials are generated by drilling with an overbearing pressure, slitting the mudcake in a borehole, acid injection, or any of various other manners which causes fluid movement. The data obtained is interpreted to locate fractures, measure formation permeability, estimate formation pressure, monitor drilling fluid loss, detect abnormal pressure, etc. Particularly, a streaming potential voltage transient having a double peak profile signifies the presence of a formation fracture.

Abstract: The present invention provides a novel use of a material having a high internal magnetostrictive damping and/or using material with explicitly low magnetostriction as an antenna core material for NMR and resistivity devices in a borehole. The probe stuctural geometry facilitates the use of material, which has a relatively low magnectic permeability.

Abstract: A sensor for measuring mud resistivity in a borehole includes a transmitter having a magnetic moment in a first direction; and a receiver having a magnetic moment in a second direction, wherein the first direction and the second direction are substantially different, wherein the transmitter and the receiver are disposed in an insulating collar of a downhole tool, and wherein the transmitter is disposed at a selected distance no more than 10 inches from the receiver along a longitudinal axis of the downhole tool.

Abstract: The present invention discloses a method and system compensating for thermally induced motion of probe cards used in testing die on a wafer. A probe card incorporating temperature control devices to maintain a uniform temperature throughout the thickness of the probe card is disclosed. A probe card incorporating bi-material stiffening elements which respond to changes in temperature in such a way as to counteract thermally induced motion of the probe card is disclosed including rolling elements, slots and lubrication. Various means for allowing radial expansion of a probe card to prevent thermally induced motion of the probe card are also disclosed. A method for detecting thermally induced movement of the probe card and moving the wafer to compensate is also disclosed.

Abstract: The embodiments of the invention are directed to a new apparatus and method of measuring the water content using time domain reflectometry (TDR), or electrical conductivity in deep soil levels to. The method uses flat, flexible, waveguides attached to a flexible sleeve filled with a filling material which press the flexible waveguides against an irregularly shaped interior borehole wall.

Abstract: This invention provides methods, NMR probes, and NMR systems for the analysis of the contents of sealed food and beverage containers and the like.

Abstract: A method for determining virgin formation temperature of earth formations surrounding a borehole is provided. The time duration of drilling fluid circulation and the time after cessation of drilling fluid circulation at the borehole depth regions of interest are tracked. At a particular borehole depth region of interest, fluid flows from the formations into a device in the borehole, and the temperature of the fluid as a function of time with respect to initiation of fluid flow is measured. The thermal history of formations surrounding the particular borehole depth region is modeled for a cooling phase during drilling fluid circulation, a temperature build-up phase after cessation of drilling fluid circulation, and a formation fluid flow phase after initiation of fluid flow. The model and temperature measurements are used to determine a trend of temperature evolution and the virgin formation temperature by extrapolation from the trend.

Abstract: A fault indicator for indicating the occurrence of a fault in an electrical conductor has a housing, a high capacity battery, a display for indicating the occurrence of a fault, a current sensor for sensing the load current in a monitored conductor a microcontroller for determining the load current, for selecting one of a plurality of trip settings, such as in several steps between 50 A and 1200 A, based upon the determined load current and for determining that a fault condition occurred when the load current exceeds the trip setting. The selected trip setting is stored in memory. The load current is periodically sampled and the trip setting is changed if the load current falls in a different range. The display may include permanent and temporary fault indicating LEDs and additional internal LEDs that cause the housing to glow or flash at nighttime, or a target style display may be used. Upon the load current exceeding the trip setting, the microcontroller begins flashing the permanent fault LEDs.

Abstract: A handheld dual voltage circuit tester, method and electronic circuit that quickly allows a technician to determine whether an automotive electrical system runs on a 12-14 volt circuit or 36-42 volt circuit. The tester may be used for automobiles having a single voltage electrical system, or automobiles with distinct electrical systems operating on one of a 12-14 volts circuit or a 36-42 volt circuit. The tester includes a screwdriver-type elongated handle and probe tip. The tester also includes electronic circuitry disposed within its handle, heat shrink tubing, a conductive spring assembly, a strain relief, a retractable coil cord, a ground clip and insulation that encloses the ground clip. The tester also includes electronic circuitry that emits light of a first color when a 12-14 volt circuit is sensed, and light of a second color when a 36-42 volt circuit is sensed.

Abstract: It is an object to provide an MR system and a floor cover capable of being attached and detached by one operator. In the invention, the floor cover covers a front face of a lower part of an open type MR system, and a cradle on which an object is mounted swiftly moves thereon. The floor cover is provided with a slide capable of moving on the lower part.

Abstract: Apparatus and methods of measuring the electrical resistance of electrically-conductive materials are disclosed. In one aspect, an apparatus includes a substrate, and first, second, third, and fourth elongated conductive members. Each conductive member includes a first portion at least partially disposed on the substrate and a second portion. Each of the first portions is spaced apart from one or more adjacent first portions and is engageable with the electrically-conductive material along a contact length. The apparatus may include a source operatively coupled to the second portions of the first and fourth conductive members, and a meter operatively coupled to the second portions of second and third conductive members.

Abstract: The invention relates to a chuck apparatus for a wafer probe station in which the central conductive surface supports a device-under-test (DUT) over a conductive lower chuck portion. An insulator positions the center conductor surface of the chuck above the lower chuck portion and also positions an electrically isolated conductor along its periphery. A laterally extending shielding element is provided for shielding electromagnetic interference (EMI) from the center conductor surface and the lower chuck portion. The electrically isolated conductor and the conductive lower chuck portion may cooperate to form a line-of-sight electrical barrier between the center conductor surface and the laterally extending shielding element. The invention further relates to methods of manufacturing the chuck apparatus and using the apparatus to accomplish low current and voltage tests in a probe station.

Abstract: A mud resistivity measuring device for use in a borehole includes a pair of current electrodes disposed between a pair of guard electrodes. The measure electrodes are carried on a recessed portion of a logging tool so that the measure current flows substantially along the borehole axis and is relatively insensitive to the formation resistivity. A pair of measure electrodes on the logging tool determines a voltage difference caused by the current flow in the borehole.

Abstract: A heater cable is deployed in a well bore to elevate the temperature of the wellbore above the temperature of the surrounding fluid and the formation. One or more fiber optic strings are included in or carried by the heater cable which is placed along a desired length of the wellbore. At least one fiber optic string measures temperature of the heater cable at a plurality of spaced apart locations. Another string is utilized to determine the temperature of the wellbore. The heater cable is heated above the temperature of the well bore. The fluid flowing from the formation to the wellbore lowers the temperature of the cable at the inflow locations. The fiber optic string provides measurements of the temperature along the heater cable. The fluid flow is determined from the temperature profile of the heater cable provided by the fiber optic sensors.

Abstract: A non-linear junction detector (“NLJD”) detects junctions between two materials exhibiting dissimilar electronic or electrical properties, such as semiconductor junctions or junctions between dissimilar metals. A target junction is illuminated with energy at a fundamental RF frequency and reflections from the non-linear junction are analysed to determine the type of junction detected. The NLJD automatically controls the power output level of a transmitter emitting the illuminating signal so as to drive the signal strength of said received signals towards a predetermined value, e.g. a minimum threshold value. Advantages of the invention are improved system efficiency and the elimination of target saturation effects and unwanted device triggering/indications.

Abstract: A method for measuring properties of a flowing fluid composition comprising at least two different components, while the fluid composition is flowing through a duct or channel, which flow meter comprises: at least one sensor (2, 3) in the shape of a cavity resonator through which at least a portion of the fluid composition passes; at least one electronic circuit (4) comprising a transmitting means (11) adapted to transmit an electronic signal (9) into the flowing fluid via a probe (7, 11); at least one receiving means adapted to receive a signal which has traveled through the flowing fluid composition; and at least one signal processing unit (12) adapted to deduce fluid specific signals from the received signals. An oscillator included in the electronic unit (4) may, in a preferred embodiment, be phase locked to the resonant frequency of the sensor (2, 3) (in a so-called FSA (feedback self-oscillating amplification) method).

Abstract: A high-precision inspection apparatus and method for inspecting a large board with a line sensor camera, the coordinate positions of correction marks on a pair of holding members are read by the camera and compared with predetermined coordinates, and an amount of positional discrepancy of the board is computed. The board is adjusted according to the positional discrepancy, if necessary, and then scanned.

Abstract: A unique means in interpreting anisotropic reservoirs in thinly laminated earth formations regardless of the hole deviation is provided. A high-resolution micro-resistivity formation measurement is used to estimate in real time at the well site the formation anisotropic electrical parameters oriented around the borehole drilled with a conductive fluid. Estimations of the formation anisotropy or hydrocarbon profile are compared and combined with indicators associated with the formation to provide improved evaluations of hydrocarbon content over conventional methods.

Abstract: Sensors are permanently placed in the ground near observation and injection wells in order to passively and continuously monitor the status of seawater advance toward fresh water aquifers near coastal cities as well as the status of fresh water injected into the injection wells. Such sensor devices are installed in the ground and electrically connected to surface acquisition equipment that would, without human intervention, transmit acquired data to a centralized facility for processing and interpretation. Various types of sensors can be used: the sensors used for general reservoir monitoring and/or the sensors used for leak detection, soil heating, and temperature mapping. Alternatively, a special type of sensor can be designed and provided for the purpose of monitoring the status of seawater advance toward fresh water aquifers.

Abstract: A method of measuring the resistivity of drilling mud in a borehole passing through a terrestrial formation includes the steps of a) inserting a sonde into the borehole, the sonde having an elongate body provided with at least one annular current electrode (A0, A′0) and at least two annular guard electrodes (A, A′, A1, A′1, A2, A′2) situated on either side of the annular current electrode; b) performing computed focusing to simulate an operating mode in which at least one current I0 is emitted into the surrounding formation from the annular current electrode, the current I0 being focused in the formation by emitting two currents I1 and I′1 from the two annular guard electrodes situated on either side of the annular current electrode; and c) producing a signal representative of the resistivity Rm of the drilling mud from the simulated operating mode.

Abstract: A magnetic method is disclosed that can be used to map, track and monitor the progress of secondary oil recovery during water or steam floods. An electric current is injected directly into the water hydrocarbon system to be monitored. The electricity that flows in the water creates a magnetic field, which can be monitored. Monitoring the changes in the magnetic field monitors the changes in the water flooding the subsurface hydrocarbon zone. The resulting surface magnetic field is measured at various time intervals. Variation in magnetic field is used to interpret and determine the status of the hydrocarbon recovery zone.

Abstract: The method of the invention makes it possible to determine the hydrocarbon flow rate Qhe in an oil well in production, by causing data acquisition apparatus to pass along the well once only, the data acquisition apparatus being provided with local sensors making it possible to distinguish between water and hydrocarbon. During the single pass, the hydrocarbon bubble count Bc per unit time, the water holdup Hw in the fluid, and the flow section A of the well are measured.

Abstract: The invention relates to a method of measuring the resistivity of a drilling mud by means of a sonde provided with an annular current electrode (A.sub.0) and with annular guard electrodes (A, A'), current I.sub.0 being emitted into the surrounding formation together with focusing currents I and I'. A signal representative of R.sub.m is produced in response to I.sub.0. Various apparatuses for implementing the method are described. Another method implements a technique of computed focusing. Corresponding apparatuses are also described.

Abstract: A method and apparatus for navigating a tool string down a subsurface borehole to its intended location while simultaneously measuring or sensing the borehole environment, electrically, acoustically, mechanically, or by nuclear means, for a characteristic parameter. The hole-finder apparatus incorporating a locally flexible body adapted for attachment to the tool string. As the tool string is navigated through the borehole, the flexible body provides extreme local flexibility to lessen the likelihood of jamming the tool string while tripping down the borehole by providing a lateral force at the obstruction. The hole-finder apparatus further including a sensor or probe measuring means attached to or within the tip of the flexible body for measuring the characteristic parameter.

Abstract: A method for generating a flow profile of a wellbore whereby a resistivity tool is run through the wellbore, while the wellbore is being drilled, to sequentially measure and record, at each of a sequence of selected points along the wellbore, a sequential series of resistivities measured while drilling (MWD). Fluid from the wellbore is then allowed to permeate into the formation. The resistivity tool is then run through the wellbore, after the drilling mud has permeated into the formation, to sequentially measure and record, at substantially the same points at which the MWD resistivity measurements were made, a sequential series of resistivities measured after drilling (MAD). For each point, the arithmetic difference between the MWD resistivity and the corresponding MAD resistivity recorded for the respective point is calculated.

Abstract: Apparatus for insertion in a well which is producing fluids from multiple zones for measuring the concentration of water in the fluids flowing through the well to determine which zone may be producing excessive quantities of water. The apparatus transmits microwave frequency range radiation within a section of the wellbore. The apparatus may utilize a portion of the well casing and a conductor member which is centered in the wellbore by spaced apart centralizers to form a coaxial transmission line within the wellbore. The apparatus may be traversed through the wellbore on a wireline type cable for continuous measurement of the water content of the water-oil mixture flowing through the well to determine which zone is producing excessive amounts of water into the production fluids.

Abstract: A two-port, coaxial, waveguide flowline sensor for transmitting TEM mode electromagnetic radio frequency signals through borehole fluids flowing through a longitudinal flowline cavity of the waveguide. The waveguide flowline sensor responds to changes in the conductivity, dielectric constant, and state of the fluid at high borehole temperatures and pressures. The sensitivity of the sensor is enhanced by impedance mismatches between two feedthrough waveguides comprising the ports of the sensor, and a flowline cavity waveguide.

Abstract: A method for producing, in a hydrocarbon well, a signal indicative of a local flow parameter of a multiphase fluid, includes the steps of placing at least one local sensor in the fluid and producing a signal whose level is characteristic of the phase in which the sensor is immersed, the signal being generated at a spike whose radius of curvature is less than 100 microns. The method is applicable to determining hold-ups of different phases of the fluid.

Abstract: An improved method for modeling a stratified and fractured geological environment is disclosed. The method produces a geometric model of a multi-layered fractured sedimentary medium by performing the steps of obtaining from the medium data relating to fracturation densities n(i)per unit of length in different layers of the medium and interruption densities s(i/j) of fractures in each layer (i) interrupting at interfaces with adjacent layers (j); forming a stratified model having a plurality of strata S(i) with fractures represented as traces across each stratum; and positioning each trace with a determined fractural extension by randomly selecting the measured fracturation densities n(i) and interruption densities s(i/j).

Abstract: A method and apparatus for automatically detecting a lubricant type and the relative quantity of water present in a test sample of lubricating oil includes the use of an open grid capacitive sensor element that incorporates the lubricating oil as a dielectric medium. The sensor element grid is energized by a frequency variable oscillator that automatically responds to changes in the oil dielectric constant with corresponding frequency changes. As a reference, a sample of new or uncontaminated test oil is confined in wet surface contact with the energized, open grid sensor element. Oscillator frequency changes are measured and recorded, either continuously or at frequent intervals, over a standardized elapsed time interval to generate a reference characterization of the frequency-time relationship distinctive of the particular oil. The same is repeated for a sample of contaminated oil and a corresponding frequency-time relationship generated.

Abstract: An improved formation testing method increases the accuracy of in-situ formation pressure measurements by characterizing the mudcake properties. Specifically, after a formation tester is lowered to a desired depth within a wellbore, a pad is extended to gently abut and seal against the mudcake without disturbing the mudcake. When pressed against the mudcake, the pad experiences momentarily higher pressures, which are measured by a probe housed by the pad. These pressures may be enhanced by briefly rejecting fluids through the probe, so as to avoid disturbing the mudcake. The probe continues to measure pressure, which eventually decreases relative to hydrostatic pressure in the wellbore, due to the flow of high-pressure wellbore fluids through the mudcake.

Abstract: A method and apparatus for sensing one or more physical parameters, including acoustic waves having frequencies from approximately 0 Hz to 15 Hz, electromagnetic waves having frequencies from approximately 0 Hz through 35 Hz and seismic waves having frequencies from approximately 0 Hz through 15 Hz, and detecting precursor seismic activity indicated therein. Acoustic waves are sensed using an infrasonic transducer that produces an electrical signal representative of such waves. Electromagnetic waves are sensed using a suitable antenna, the antenna preferably comprising AC power lines. The antenna produces an electrical signal representative of such waves. Seismic waves are sensed using an accelerometer that produces an electrical signal representative of such waves.

Abstract: An early warning system for providing notice that seismic activity, such as an earthquake, is imminent. The earthquake early warning system includes a subterranean detector unit assembly having a plurality of detector units carried by a subterranean inverted conduit. The conduit is filled with a dense, dry inert aggregate and has a soil interface consisting of a perforated metal screen or porous fabric material thus allowing migrating gases to migrate into the conduit. Gas detectors carried by the conduit detect the gases as they migrate into the conduit. Access tubes are provided to allow access to the detectors from the surface of the ground without exhuming the conduit assembly. The conduit would carry a plurality of detectors and associated access tubes for monitoring migration of gases across a linear distance. The detectors are in communication with a monitoring facility for monitoring the rate of migration of gases.

Abstract: A logging apparatus is adapted to be disposed in a mud filled wellbore, and a measurement probe is connected to a bottom of a tool string of the logging apparatus. The measurement probe is adapted for measuring a resistivity of a mud in the mud filled wellbore. The measurement probe includes a bottom electrode disposed on a bottom of the probe when the logging apparatus is disposed in the wellbore, a second electrode, and at least one measurement electrode disposed adjacent the bottom electrode for measuring a voltage potential drop in a region of the mud which is disposed directly below the bottom electrode of the measurement probe when the probe is disposed in the wellbore. When the measurement probe is energized, a current flows in the mud between the bottom electrode and the second electrode.

Abstract: The invention is a method of determining the flow regime of fluid having more than one phase flowing in a conduit. The method includes the step of positioning a sensor in the conduit, the sensor generating measurements capable of discriminating more than one phase in the fluids, generating measurements from the sensor for a period of time, characterizing the measurements with respect to changes in magnitude of the measurements occurring during the period of time, and comparing the characterized measurements to similarly characterized measurements of a similar sensor positioned within flow streams having known flow regimes.In a preferred embodiment of the invention, the characterization of the measurements includes performing a variability analysis of the measurements.

Abstract: An improved system for measuring dielectric properties of fluids in an oil well, utilizing the well casing as a waveguide for certain electromagnetic signals. A production logging tool in accordance with the invention includes a cylindrical mandrel sheathed by a housing. Transmitting and receiving coils are contained in annular grooves defined in the mandrel. In operation, the tool is suspended by a wireline logging cable within the casing of a producing well. The transmitting coils generate magnetic fields and azimuthal electric fields, which induce voltages in the receiving coils. These voltages are affected by the dielectric properties of fluids in the casing, and the voltages may be interpreted to determine dielectric properties such as water resistivity, dielectric permittivity, water hold-up, water cut, and water salinity.

Abstract: An early warning system for providing notice that seismic activity, such as an earthquake, is imminent. The earthquake early warning system includes a subterranean detector unit assembly having a plurality of detector units carried by a subterranean inverted conduit. The conduit is filled with a dense, dry inert aggregate and has a soil interface consisting of a perforated metal screen or porous fabric material thus allowing migrating gases to migrate into the conduit. Gas detectors carried by the conduit detect the gases as they migrate into the conduit. Access tubes are provided to allow access to the detectors from the surface of the ground without exhuming the conduit assembly. The conduit would carry a plurality of detectors and associated access tubes for monitoring migration of gases across a linear distance. The detectors are in communication with a monitoring facility for monitoring the rate of migration of gases.

Abstract: The pressure build-up of hydrocarbon wells is quickly measured allowing the well to be shut-in for a shorter length of time than previously possible to achieve the same results. After the well has been shut-in at the surface the rate of change of the level of the gas/liquid interface within the well bore is determined. The level change data are converted into pressure build-up data and flow rate data. Applying the convolution integral to the pressure build-up data gives the value of the equilibrated pressure of the well. The deconvoluted data can then be used to solve conventional algorithms to determine the state of the well bore and surrounding formation. The operator of the well can then make a variety of decisions, including continuing to produce from the well, stimulating the well, or abandoning the well.

Abstract: There is disclosed in the present specification a method and apparatus for use of a downhole formation multi-tester instrument in the characterization of formation fluids, including measurement of the conductivity of water, often in the presence of hydrocarbons under dynamic flow conditions and determining the hydrocarbon volume of the formation fluid. Utilizing a coaxial transmission line as a flow tube within the formation multi-tester instrument an electromagnetic wave is generated which propagates through the formation fluid in a transverse electromagnetic mode. Measurement of the phase shift and attenuation of the electromagnetic wave at points within the flow tube allow characterization of the fluid inside the cavity of the flow tube for dielectric constant and conductivity. Dielectric constant and conductivity can then be related to fluid conductivity and hydrocarbon volume.