Abstract: A method of monitoring gas in a downhole environment is discussed which provides downhole a mid-infrared light emitting diode, operates the diode to transmit respective infrared signals on a first optical path extending from the diode through a downhole gas sample and a second optical path extending from the diode through a reference gas sample, detects the transmitted infrared signals, and determines the concentration of a component of the downhole gas sample from the detected signals.

Abstract: The invention describes a method of cement lining a wellbore to enable a fixed sensor internal of the lining to sense characteristics of the external formations surrounding the wellbore using, at the region of the sensor position, a permeability changing device before completion of setting of the cement to create, in use, a permanent fluid communication through the cement lining between the external formation and the sensor.

Abstract: A method and system is disclosed for communicating information from a downhole location to the surface including a plurality of releasable vessels containing predetermined signal information affixed to the vessels prior to placement of the vessels downhole and indicative of the presence of at least one of three or more predetermined downhole conditions and a sensing and releasing system that senses the occurrence of the downhole condition, such as a simple threshold, and release the vessels in response to the sensing. The predetermined downhole condition can be characteristic of the fluid being produced in the borehole, such as water fraction, a certain level of mechanical wear or damage to downhole equipment such as bit wear, or the firing a one or more charges on a wireline deployed perforation tool.

Abstract: A control system for a hydrocarbon well is also disclosed. A control valve system is used to control the flow of fluid being produced by the well. A real time sensor is provided downhole and is used to make real time measurements of phase characteristics of the fluid. A controller is used to control the valve system so as to reduce the risk of undesirable phase transitions in the fluid based on the real time measurements made by the sensor. The sensor includes an acoustic transducer configured to emit acoustic energy into the fluid at a level which causes a phase transition in the fluid. The controller determines the level of acoustic energy emitted into the fluid, and also determines the pressure associated with a phase transition using the level of emitted acoustic energy.

Abstract: A method and system for publishing information on a network-based computer system is disclosed using a network of client computers, network file server and a Light Weight Directory Access Protocol (LDAP) directory server, wherein the LDAP directory server is adapted to store information defining and limiting the rights of authors and readers in the system; and the network file server is adapted to resolve file server pointers to one or more files on the file server and directory files on the LDAP directory server transmitted from the client computer into requests for files and directory files; to retrieve from the LDAP directory server directory content; and to convert the directory content into web-publishable information and including the web-publishable information as part of the requested files displayed on the client computer for editing further parts of the files.

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: Improved methods, apparatus, and systems for obtaining information regarding a formation, a casing, or fluid within the casing utilize an interrogator and one or more sensing devices attached to a casing in a wellbore. The interrogator, which is located and typically movable inside the wellbore, is effectively a toroidal transformer which includes an elongate conducting body surrounded by a core of high magnetic permeability material and carrying a winding. The sensing device, which is positioned and fixed in an opening cut in the casing, includes a housing, a sensor with associated electronic circuitry and an electrode. The electrode is insulated from the casing by an insulator, and the housing of the sensing device is typically adapted to provide a hydraulic seal with the opening in the casing. The interrogator and sensing device communicate in a wireless manner.

Abstract: A sensing apparatus is provided for use downhole, comprising a housing and sensing means with the housing containing a plurality of separable elements to which data acquired by the sensing means is transferred. The separable elements are releasable from the housing to convey the acquired data to surface. The separable elements have a spherical outer casing of around 1 to 10 cm diameter which surrounds a memory chip. The casing has a sealable aperture so that electrical connection to the chip can be established within the housing.

Abstract: A modification to the Coates-Timur relationship to produce a more coherent relationship applicable to carbonate formations is disclosed. In this method, permeability may be determined using porosity and the ratio of bound fluid volume to (1—bound fluid volume). This method also allows for improved estimation of irreducible water saturation of a carbonate formation using the ratio of kc and (e?f+kc). Likewise, the bound fluid volume of a carbonate formation may be determined using the ratio of ?kc and (e?f+kc). In these relationships, e, x, and f are constants according to the following relationships e=xc, f=bc+1, x is between 1 and 100 mD (preferably 10 mD).

Abstract: A method of processing sonic wireline or logging while drilling data acquired in a borehole that includes filtering the sonic data to attenuate tool-borne and borehole-borne arrivals; migrating the filtered sonic data; and beamforming the filtered and migrated sonic data to determine a position of a reflector with respect to the borehole. The sonic data may be processed down-hole, transmitted to the surface, and used for geosteering purposes while drilling. The filter may comprise an adaptive noise-attenuating filter capable of attenuating noise arising from different borehole modes from desired signal and allowing for changes in the source signature.

Abstract: The present invention relates to a method and apparatus for determining the presence of magnetic materials in a media, such as an earth formation. More specifically, the method of the present invention correlates a diffusion-relaxation calibration function representative of magnetic materials with a 2-D function developed using diffusion-editing to determine the presence and relative content of magnetic materials in a media.

Abstract: The present invention discloses a diffusion edited pulse technique that allows information about a fluid to be extracted, comprising: a) obtaining a fluid sample; b) generating a sequence of magnetic field pulses in the fluid, the sequence comprising an initial magnetic field pulse, a first portion that follows the initial magnetic field pulse, and a second portion that follows the first portion; c) detecting magnetic resonance signals using the second portion of the sequence; d) modifying the first portion of the sequence, and repeating steps (b) and (c); and e) extracting information about the fluid by determining relaxation and diffusion characteristics and their correlation based on the signals detected in steps (c) and (d). Also disclosed is a logging tool equipped with a processor to implement the diffusion edited pulse technique.

Abstract: A method and system of monitoring the movement of at least one front in an inter-well region is comprised of: providing a first well representing the origination of at least one front (such as a saturation front or a salinity front); providing one or more monitoring locations, each equipped with at least one sensor; and monitoring the arrival of at least one front at one or more monitoring locations. The origination well may be any type of permanent or temporary well, but is preferably an injector well. Likewise, the monitoring location(s) may be any type of permanent or temporary well such as an observation well, a production well, an exploratory well, and an appraisal well. Information regarding front arrival times may be used to characterize or appraise the formation. Front arrivals may be monitored as a function of time to develop their respective time evolution and shape.

Abstract: The present invention relates to a method and apparatus for determining the wettability of a porous media, such as bone, plant, food, wood or molecular sieves, etc., having two or more fluids. The method of the present invention correlates a diffusion-relaxation calibration function representative of at least one fluid in the porous media with a 2-D function developed using diffusion-editing to determine wettability of the porous media.

Abstract: In one embodiment of the present invention, a method of measuring the molecular displacement of a fluid is disclosed comprising: (a) applying a strong magnetic field gradient to the fluid; (b) applying a sequence of oscillating magnetic field pulses to the fluid wherein the sequence includes a first portion followed by a second portion, wherein the first portion spatially modulates the magnetization state of the fluid and the second portion monitors the evolution of the modulation; (c) detecting magnetic resonance signals from the fluid; and (d) analyzing the detected signals to determine the molecular displacement of the fluid. This method may be used to determine the diffusion of the fluid or the restricted diffusion of the fluid through the porous media if the fluid is within a porous media (such as earth formation, bone, wood or other material). Also disclosed is a logging tool configured to implement this methodology.

Abstract: The present invention discloses a method and apparatus to make a nuclear magnetic resonance measurement on a flowing fluid using varied wait times. In one method, NMR measurements are made by: a) flowing the fluid through a static magnetic field; b) applying a group of oscillating magnetic field pulses to the flowing fluid, wherein the group of pulses is comprised of an initial pulse and one or more refocusing pulses; c) detecting magnetic resonance signals from the flowing fluid; d) after a wait time, repeating (b) and (c) one or more times, wherein at least two of the repetitions have varied wait times; and e) analyzing the detected magnetic resonance signals to extract information about the flowing fluid. Further, varied wait time measurements may be useful in determining the flow rate of the sample.

Abstract: Nuclear magnetic resonance techniques are used in a fluid sampling tool that extracts a fluid from subsurface earth formations into a flow channel within the tool. The magnetic resonance techniques involve applying a static magnetic field and an oscillating magnetic field to the fluid in the flow channel, and magnetic resonance signals are detected from the fluid and analyzed to extract information about the fluid such as composition, viscosity, etc.

Abstract: The present invention discloses an acoustic resonator device capable of nucleating bubbles in a formation fluid under borehole-like conditions wherein the static pressure is higher than the bubble point pressure. The device is comprised of one or more coaxial layers forming a central conduit, wherein at least one of the coaxial layers is comprised of an electro-acoustic transducer material such as including piezoelectric or magnetorestrictive materials. This device is preferably designed to be in fluid communication with a host tool to allow in-situ sampling and bubble point determination. Also disclosed is an in-situ method of fluid analysis in a borehole for determining phase characteristics of a formation fluid using the device. Cavitation may be induced using the device in either a captured volume sample or a flow-line sample.

Abstract: A shaftless acoustic source is disclosed having a solenoid, a bullet and driving electronics. The bullet, which is positioned inside the solenoid's coil, can be accelerated by a magnetic force generated when a current pulse is applied to the coil. Acoustic energies are generated upon the impact of the bullet with an object, such as a borehole wall. This impact force can be described by the Hertzian Contact Theory (also referred to herein as Hertzian Theory) as a point of normal force with a time function similar to a half period sine function. A retraction device may be used to retract the bullet back into the solenoid after firing.

Abstract: The present invention discloses a method and apparatus to detect bubbles in a fluid sample to determine if gases are present, wherein an ultrasonic source is used and its properties monitored. Fluctuations in the ultrasonic source's electrical properties indicate the presence of bubbles/gas. Alternatively, the ultrasonic source may be used to cavitate the sample and induce the nucleation of bubbles. In such a system/method, bubbles may be detected by either (1) monitoring the ultrasonic source properties, (2) monitoring the compressibility of the sample, (3) monitoring the sample properties, including harmonics and subharmonics. The method and apparatus disclosed herein may be used in a borehole such as with a sampling means (including either a flowing sample or a stationary sample) or in a surface lab.