1
Charles L Melcher, Ralph A Manente, Jeffrey S Schweitzer: Methods and apparatus for gamma-ray spectroscopy and like measurements. Schlumberger Technology Corporation, Brumbaugh Graves Donohue & Raymond, November 28, 1989: US04883956 (52 worldwide citation)

Improved borehold logging methods and apparatus for detecting and measuring photon and other radiation from earth formations. Such radiation may be, for example: natural; generated by a source and modified by interaction with formation constituents; produced during or immediately following interacti ...


2
Felix K Chen, William Bertozzi, Gary W Corris, William Diamond, Joseph A Doucet, Jeffrey S Schweitzer: Circular induction accelerator for borehole logging. Schlumberger Technology Corporation, Richard G Berkley, Leonard W Pojunas, June 16, 1992: US05122662 (30 worldwide citation)

A compact circular magnetic induction accelerator (betatron) for use as a borehole gamma ray source includes a field magnet and generally circular pole pieces composed of a class of ferrite having the general formula M.sup.2+ Fe.sub.2.sup.3+ O.sub.4, where M represents two or more divalent metal ion ...


3
Peter D Wraight, Russel C Hertzog, Darwin V Ellis, Hubert D Scott, Jeffrey S Schweitzer, James A Grau: Logging apparatus and method for determining absolute elemental concentrations of subsurface formations. Schlumberger Technology Corporation, Chilton Alix & Van Kirk, March 7, 1989: US04810876 (26 worldwide citation)

Logging apparatus and methods for detecting first signals indicative of the absolute concentrations of the first category of elements in the rock matrix, for irradiating the formation with a pulse of high energy neutrons and for detecting a second signal indicative of the relative concentrations of ...


4
Seikichi Akiyama, Hiroyuki Ishibashi, Takeshi Utsu, Charles L Melcher, Jeffrey S Schweitzer: Single crystal scintillator. Hitachi Chemical, Leonard W Pojunas, November 23, 1993: US05264154 (23 worldwide citation)

A single crystal scintillator and apparatus for prospecting underground strata using the scintillator is described. The single crystal scintillator is a cerium doped gadolinium silicate compound of the formula:


5
Jeffrey S Schweitzer, Ralph M Tapphorn: Method for investigating the front profile during flooding of formations. Schlumberger Technology Corporation, Brumbaugh Graves Donohue & Raymond, April 25, 1978: US04085798 (21 worldwide citation)

A method of determining the flood front profile created during the production flooding of an oil-bearing formation utilizes cased observation boreholes located between the injection wells and the producing wells. The time and depth of arrival of the flood front at an observation borehole are detecte ...


6
Ralph A Manente, Frank Bruni, Charles L Melcher, Carl A Peterson, Jeffrey S Schweitzer: Method of growing lutetium oxyorthosilicate crystals. Schlumberger Technology Corporation, Brigitte L Jeffery, Leonard W Pojunas, Martin D Hyden, August 26, 1997: US05660627 (19 worldwide citation)

A method for producing lutetium oxyorthosilicate crystals includes maintaining the interface between a crystal and the melt from which it is pulled substantially flat as the crystal is grown. In a Czochralski growth method, the rate of rotation of the crystal and its diameter are typically controlla ...


7
Bradley A Roscoe, Jeffrey S Schweitzer, Kenneth E Stephenson: Method of measuring flow velocities using tracer techniques. Schlumberger Technology Corporation, Martin D Hyden, Leonard W Pojunas, August 6, 1996: US05543617 (10 worldwide citation)

A method of measuring flow velocities in flowing fluids includes injecting into the flow a non-radioactive tracer having a neutron capture cross section higher than that of the flowing fluids, for example a gadolinium compound, and measuring the neutron capture cross section in the fluid downstream ...


8
Jeffrey S Schweitzer, Ralph M Tapphorn: Lithology determination from the calcium and magnesium activation lines. Schlumberger Technology Corporation, Brumbaugh Graves Donohue and Raymond, June 17, 1980: US04208580 (6 worldwide citation)

In the illustrative embodiments of the invention disclosed, the lithology of an earth formation traversed by a well bore is investigated by irradiating the formation with a neutron source and generating an energy spectrum of the activation gamma rays resulting therefrom. From the spectrum thus obtai ...


9
Charles L Melcher, Jeffrey S Schweitzer: Method of growing lutetium aluminum perovskite crystals and apparatus including lutetium aluminum perovskite crystal scintillators. Schlumberger Technology Corporation, Leonard W Pojunas, Keith G W Smith, William B Batzer, October 5, 1999: US05961714 (6 worldwide citation)

A method for producing lutetium aluminum perovskite crystals includes heat aging the crystal melt and maintaining the interface between a crystal and the melt from which it is pulled substantially flat as the crystal is grown. In a Czochralski growth method, the rate of rotation of the crystal and i ...


10
Jeffrey S Schweitzer, Ralph M Tapphorn: Salinity and lithology determination from the sodium and chlorine activation lines. Schlumberger Technology Corporation, Brumbaugh Graves Donohue & Raymond, September 13, 1983: US04404467 (5 worldwide citation)

In the illustrative embodiments of the invention disclosed, the lithology and salinity of an earth formation traversed by a well bore are investigated by irradiating the formation with a neutron source and generating an energy spectrum of the activation gamma rays resulting therefrom. From the spect ...