Mitsubishi Chemical Corporation

Other

Mitsubishi Denki Kabushiki Kaisha

Japan National Oil Corporation

Ryosuke Taniguchi

Takashi Shimada

Takahiro Sakamoto

Chizuko Furo

Shinichi Hattori

Yasuhiro Hirano

Noritaka Egami

Takahiro Saka

Kanji Matsuhashi

Shusaku Mandai

Ken Sato

Kenji Shinohara

Kenji Furui

A diverting agent is provided which does not completely dissolve in water and seawater in an ultra-low temperature to low temperature range (5° C. to 30° C.) for a certain period of time (about 5 minutes to 3 hours), and is quickly dissolved and removed after a certain period of time in an excavation method using a hydraulic fracturing method. Also provided is a diverting agent containing a polyvinyl alcohol-based resin having 2.3 mol % to 15 mol % of a hydrophilic modifying group in a molecular structure thereof.

Diverting agent and method of filling fracture in well using same

An object of the present invention is to provide a diverting agent that can exhibit sufficient filling properties against a fracture in a well in an excavation method using a hydraulic fracturing method, and that is excellent in solubility after a predetermined period of time has passed. The diverting agent of the present invention contains a polyvinyl alcohol-based resin having an average polymerization degree of 1000 or more.

A diverting agent is provided that exhibits sufficient filling properties against a fracture in a well because of swelling without complete dissolution for a certain period of time (about 30 minutes to 5 hours), and that quickly dissolves and can be removed even at a low temperature of 40° C. to 60° C. after a certain period of time has passed. Also provided is a diverting agent that contains a modified polyvinyl alcohol-based resin.

A diverting agent is provided which has solubility in water that can be controlled excellently and which does not easily dissolve at an early stage of filling of fractures in a well in excavation method using a hydraulic fracturing method and dissolves in water and can be easily removed after filling is no longer needed. The diverting agent contains powdery polyvinyl alcohol-based resins having an average particle diameter of 800 to 2000 μm.

Diverting agent and method of filling fracture in well using the same

A diverting agent of the present invention contains a polyvinyl alcohol-based resin, wherein when the diverting agent is added to a 0.48 mass % aqueous solution of guar gum to prepare a mixed solution having a concentration of 12 mass %, a dispersion liquid obtained by dispersing the mixed solution at 30&#xb0; C. for 60 minutes is pressurized and dehydrated at a pressure of 1 MPa using a pressure dehydration device including a drainage part having a slit having a width of 2 mm, and a regression line represented by an equation (A): y=ax+b (in the equation (A), y is a cumulative dehydration amount (g), x is a square root of a time (minutes) elapsed from start of pressurization, a and b are a slope and an intercept of the regression line, respectively, and 0&#x3c;x&#x2264;2) is calculated by a least squares method from a scatter diagram plotted on a graph in which the square root x of the time is plotted on a horizontal axis and the cumulative dehydration amount y is plotted on a vertical axis, a slope a of the equation (A) satisfies a condition (B): a&#x2264;80.

An elastic wave generator includes an excitation coil, a magnetostriction oscillator around which the excitation coil is wound and an oscillator support. The excitation coil is wound around the oscillator, which is made of laminated magnetostriction sheets having a positive strain characteristic, in which length varies directionally upon magnetic excitation. The oscillator support has a first support surface bearing against a first end surface of the magnetostriction oscillator, intersecting the direction along which the length of the magnetostriction oscillator changes and a second support surface shrink-fit against a second end surface of the magnetostriction oscillator, intersecting the direction along which the length of the magnetostriction oscillator changes. Thus, the changes in the length of the magnetostriction oscillator due to the magnetic excitation of the excitation coil appearing at the first and second end surfaces is directly supported by the first and second support surfaces. The magnetostriction oscillator is shrink-fit by cooling so it may be placed between the support surfaces while cooled.

Method of mounting elastic wave generator

An acoustic wave transmission system comprises an acoustic wave generating metal tubular member for converting information about the bottom of a borehole, which is obtained by a bottom hole sensor, into an acoustic wave. The acoustic wave generating metal tubular member includes a acoustic wave generating mechanism having at least a magnetostrictive oscillator which is mounted in a recess formed in an outer wall of the acoustic wave generating metal tubular member, and on which a compressive load is imposed by means of a pre-load mechanism using a vise. The magnetostrictive oscillator is constructed of a stack of thin plates each made of a metal magnetostrictive material having a property of increasing its dimensions when magnetized, the thin plates being bonded together by a heat-resistant adhesive. The magnetostrictive oscillator can thus have a buckling strength large enough to resist the compressive load imposed thereon by the pre-load mechanism and a stress due to a strain caused in itself. The acoustic wave generating metal tubular member further includes an excitation current supplier for supplying either a rectangular, sinusoidal, or triangular alternating excitation current modulated with the information about the bottom of the borehole and having a frequency that is half the carrier frequency of the acoustic wave, or a series of excitation pulses modulated with the information about the bottom of the borehole and having a pulse repetition rate that is equal to the carrier frequency of the acoustic wave, to an excitation winding wound around the magnetostrictive oscillator.

Acoustic wave transmission system and method for transmitting an acoustic wave to a drilling metal tubular member

A nondestructive testing apparatus is provided with a wave transmitter by a metal-based magnetostrictive vibrator, a magnetically excited current feeding device for feeding the magnetically excited current to the magnetostrictive vibrator, a wave receiver for detecting an acoustic elastic wave propagating through the measurement object, a filter for extracting a signal in a target frequency band to be measured, and an automatically amplifying rate controlling function-equipped amplifier for automatically controlling the amplifying rate so as to obtain a given magnitude amplitude regardless of the magnitude of the reflection wave or the transmission wave detected by the wave receiver, which constitute a feedback loop. The apparatus is further provided with a signal processor for processing the signal detected by the above-described wave receiver, and a display device for displaying the process result obtained by the signal waveform detected by the above-described wave receiver or the above-described signal processor.

Nondestructive testing apparatus

A vibration exciter machine has magneto striction elements (5,6) supported by a driven pile (2), for providing a vibration of up and down direction to the driven pile (2), and a drive circuit (D1) for controlling expansion and contraction movement of the magneto striction elements (5,6) by changing a supply time period of a current supplied to the magneto striction elements (5,6). By controlling of the drive circuit (D1) the supply time period of the current which flows in the magneto striction elements (5,6) is changed to control the expansion and contraction movement of the elements (5,7). Thereby a horizontal vibration component can be eliminated and only vertical vibration component can be transmitted to the driven pile material (2).

Vibration exciter machine

An information transmitting apparatus using a tube includes a magnetostrictive vibrator to generate a first elastic wave depending upon underground information, a resonance tube body resonating with the elastic wave to generate a second elastic wave having a natural frequency, and a drill string to propagate the second elastic wave, thereby permitting a long transmission distance.

Information transmitting apparatus using tube body

A non-destructive examination device has an excitation current generation device for supplying an excitation current based on a control signal from a control device, a vibration excitor device for generating an elastic wave in accordance with athe excitation current and for vibrating an examination target to be examined by using the elastic wave; a response detection device (an acceleration sensor) for detecting a response of the vibration of the examination target caused by the elastic wave and for processing the response data in order to select desired examination information. The excitation current generation device generates the excitation current of an alternating pulse wave such as a pulse wave, or a rectangular wave, or a triangular wave, or a sine wave based on the control signal which is also a pulse signal. It can be acceptable to incorporate a plurality of the vibration excitor devices on the examination target in the non-destructive examination device.

Growing community of inventors

Tokyo, Japan

Ryosuke Taniguchi