Chung J Chang

US Patent:

6671380, Dec 30, 2003

Filed:

Feb 26, 2001

Appl. No.:

09/793685

Inventors:

Chung Chang - Wilton CT
Hiroshi Hori - Sagamihara, JP

Assignee:

Schlumberger Technology Corporation - Ridgefield CT

International Classification:

H04R 2500

US Classification:

381190, 310367

Abstract:

An acoustic transducer includes a polarized piezoelectric shell having a spiral-shaped surface. The acoustic transducer serves as a receiver or a transmitter. In one embodiment, the acoustic transducer includes a solid spiral shell having outer and inner spiral-shaped surfaces, and the shell is polarized, wired and packaged to operate in hydrophone-mode. In another embodiment, the acoustic transducer includes a shell defining an exterior spiral-shaped surface and a spiral slot; and the slot defines a closed cavity with an interior spiral-shaped surface. In a preferred bender-type receiver embodiment, the shell is polarized, wired, and packaged to operate in bender mode for maximum sensitivity and best low-frequency performance.

US Patent:

6782970, Aug 31, 2004

Filed:

Apr 25, 2002

Appl. No.:

10/138274

Inventors:

Chung Chang - Wilton CT

Assignee:

Schlumberger Technology Corporation - Ridgefield CT

International Classification:

G01V 100

US Classification:

181101, 181105, 181108, 367 86, 175 1

Abstract:

A shaftless acoustic source is disclosed having a solenoid, a bullet and driving electronics. The bullet, which is positioned inside the solenoids 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.

US Patent:

7302346, Nov 27, 2007

Filed:

Dec 19, 2005

Appl. No.:

11/311609

Inventors:

Chung Chang - Wilton CT, US
Marwan Moufarrej - Houston TX, US
Sandip Bose - Brookline MA, US
Tarek Habashy - Danbury CT, US

Assignee:

Schlumberger Technology Corporation - Ridgefield CT

International Classification:

G01V 3/18

US Classification:

702 9

Abstract:

A device and method for determining a geophysical characteristic of a borehole using at least one logging device is provided, wherein the at least one logging device includes at least one sensing device. The method includes associating the at least one sensing device with the borehole, wherein the at least one sensing device includes a sensing device measurement length. The method also includes operating the at least one sensing device to generate borehole data responsive to a borehole portion disposed essentially adjacent the sensing device measurement length, wherein the borehole data includes start time of scan, location of the at least one sensing device at start time of scan, stop time of scan and location of the at least one sensing device at stop time of scan. Furthermore, the method includes correlating the borehole data to determine the geophysical characteristic.

US Patent:

7334661, Feb 26, 2008

Filed:

Feb 5, 2004

Appl. No.:

10/772634

Inventors:

Jahir Pabon - Brookfield CT, US
Chung Chang - Wilton CT, US
David L. Johnson - Bethel CT, US
Vivian Pistre - Tokyo, JP
Tarek Habashy - Danbury CT, US
Smaine Zeroug - Ridgefield CT, US
Toshihiro Kinoshita - Sagamihara, JP
Hitoshi Sugiyama - Sagamihara, JP
Hiroshi Hori - Sagamihara, JP
Atsushi Saito - Sagamihara, JP

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G01V 1/16

US Classification:

181108, 181102, 181111, 181112, 181122

Abstract:

An acoustic logging tool sleeve with a preferably discontinuous, alternating structure that is acoustically opaque in some zones, and acoustically transparent in others. The sleeve may be modular, with several stages connected together. The multiple stages provide a sleeve that may be useful with a variety of borehole logging tools to reduce or eliminate the transmission of noise to the receiving elements.

US Patent:

7578359, Aug 25, 2009

Filed:

Dec 22, 2006

Appl. No.:

11/615526

Inventors:

Richard Coates - Middlebury CT, US
Chung Chang - Lexington MA, US
Iain Cooper - Sugarland TX, US
Marcel Boucher - Houston TX, US

Assignee:

Schlumberger Technology Corporation - Cambridge MA

International Classification:

E21B 47/14

US Classification:

175 40, 175 50, 1661771, 181106, 181113

Abstract:

An acoustic source for delivering acoustic energy to a ground formation, particularly a rock formation, the source including (a) a solenoid to generate an electromagnetic field, (b) a bullet positioned within the influence of the electromagnetic field, (c) a casing surrounding and enclosing the solenoid and bullet so that both the solenoid and the bullet are protected from the surrounding environment, in use the solenoid being electrically energized to cause the bullet to be propelled by electromagnetic force so that the bullet impacts an anvil portion of the casing in contact with the ground formation is provided.

US Patent:

7617908, Nov 17, 2009

Filed:

Nov 13, 2006

Appl. No.:

11/559252

Inventors:

Chung Chang - Lexington MA, US
Richard Timothy Coates - Middlebury CT, US
Jean G. Saint Germain - Cambridge MA, US

Assignee:

Schlumberger Technology Corporation - Ridgefield CT

International Classification:

G01V 1/02

US Classification:

181121, 181106, 181108, 181113, 367 25, 166249, 1662542, 166209, 166210, 166211

Abstract:

Elastodynamic waves are generated by a tool having a hammer rotatably connected with a housing by a first hinge and an actuator arm rotatably connected with the hammer by a second hinge. An axial force applied to the actuator arm by a drive shaft and spring is translated and amplified to a radial impact force by rotation of the hammer around the first hinge. The tool may also include a stabilizer arm connected to the actuator arm by a third hinge, and connected to the housing by a fourth hinge. The housing may be an acoustic wireline tool cylinder having an opening that permits the hammer mass to extend outside the housing when rotated in a first direction. The housing may also include a second opening that permits the hammer mass to extend outside the housing when rotated in a second direction, and a third opening that permits the hammer mass to extend outside the housing when rotated between the first and second openings.

US Patent:

7895938, Mar 1, 2011

Filed:

Oct 17, 2005

Appl. No.:

11/163385

Inventors:

Chung Chang - Wilton CT, US
Tung-Sheng Chang - Cupertino CA, US
Alexander Chang - Wilton CT, US
Chung-Hsing Chris Lee - Cupertino CA, US
Jean Saint Germain - Ridgefield CT, US

International Classification:

A47J 31/44
A23B 5/005
E21B 7/15

US Classification:

99293, 426399, 392303

Abstract:

A method and apparatus using steam to sterilize liquid dispensers. This is achieved by injecting steam into a drained dispenser machine equipped with a cover having a safety valve that matches the top of the dispenser to provide sealing. The steam is generated by a steam generator physically integrated with the new liquid dispenser machine. The steam circulates through the fluid compartment of the liquid dispenser and continues through its conduits and exits at the taps which are held open by a stepped boss. The sanitizing period can be adjusted and controlled. After sterilizing the machine, the cap of the dispenser is removed and its taps are released in order to return the machine back to its normal operation.

US Patent:

8009510, Aug 30, 2011

Filed:

Oct 23, 2008

Appl. No.:

12/256860

Inventors:

Chung Chang - Lexington MA, US

Assignee:

Schlumberger Technology Corporation - Cambridge MA

International Classification:

G01V 1/42
E21B 47/00

US Classification:

367 57, 367 25, 367 27, 175 40

Abstract:

Methods and related systems are described making seismic measurements. Seismic energy is transmitted into the earth using a surface seismic source. The seismic energy is received with one or more downhole receivers located in a borehole. In response to the received seismic energy from the surface seismic source, seismic energy is transmitted into the earth using a downhole seismic source. The seismic energy from the downhole seismic source is then received with one or more surface receivers located on the surface of the earth. A delay interval is measured downhole between the first arrival of the seismic energy from the surface seismic source and the transmission from the downhole seismic source. A surface interval is measured between the transmitting of seismic energy from the surface seismic source and first arrival of the seismic energy from the downhole seismic source using the one or more surface receivers. Travel time can be calculated by subtracting the delay interval from the surface interval.