David A. Helms has been granted 12 US patents while listed as an inventor at Chevron . The first was granted in 1985 and the most recent in April 1997. David A. Helms ranks #396,045 of 4,157,543 US inventors in our database (top 9.5%). Patent records list David A. Helms in Houston, TX, US.
Patents per Year Patents granted per year, 1985 to 1997 Bar chart with a peak of 4 patents in 1990. peak 4 1985: 1 patents 1985 1987: 1 patents 1987 1990: 4 patents 1990 1991: 1 patents 1991 1994: 1 patents 1994 1995: 2 patents 1995 1996: 1 patents 1996 1997: 1 patents 1997
Issued Patents All Time
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Showing 1–12 of 12 patents
Patent # Title Co-Inventors Date Approx Value ⓘ
5625293 Determination of the watercut of a multiphase flow directly from measured microwave frequency dielectric properties John D. Marrelli , Joseph D. Stafford , Michael G. Durrett , Gregory J. Hatton 1997-04-29
5483171 Determination of water cut and gas-fraction in oil/water/gas streams Gregory J. Hatton , John D. Marrelli 1996-01-09
$35,021,000
5473256 Combination microwave waveguide and pressure barrier Joseph D. Stafford , Gregory J. Hatton 1995-12-05
$18,821,000
5412326 Means and method for analyzing a petroleum stream John D. Marrelli , Michael G. Durrett , Lisa L. Pepin , Gregory J. Hatton 1995-05-02
$57,067,000
5315117 Volume meter system Gregory J. Hatton , Michael G. Durrett 1994-05-24
$29,543,000
5014010 Dual frequency microwave water cut monitoring means and method Michael G. Durrett , Gregory J. Hatton 1991-05-07
$13,805,000
4977377 Microwave water cut monitor with temperature controlled test cell Michael G. Durrett , Gregory J. Hatton , Earl L. Dowty , John D. Marrelli , Joseph D. Stafford +1 more 1990-12-11
$14,154,000
4947127 Microwave water cut monitor Gregory J. Hatton , Michael G. Durrett , Earl L. Dowty , John D. Marrelli 1990-08-07
$8,028,000
4947128 Co-variance microwave water cut monitoring means and method Gregory J. Hatton , Michael G. Durrett , John D. Marrelli , Joseph D. Stafford 1990-08-07
$8,028,000
4947129 Petroleum stream microwave watercut monitor John D. Marrelli 1990-08-07
$8,028,000
4660414 Petroleum stream monitoring means and method Gregory J. Hatton , Thomas M. Williams, Jr. 1987-04-28
$10,111,000
4499418 Water cut monitoring means and method Gregory J. Hatton , Thomas M. Williams, Jr. 1985-02-12
$15,314,000
