David D Fletcher

US Patent:

7117938, Oct 10, 2006

Filed:

May 30, 2003

Appl. No.:

10/449301

Inventors:

William R. Hamilton - Conroe TX, US
David Curtis Fletcher - Houston TX, US
Donald D. Rae - Willis TX, US

Assignee:

Gray EOT, Inc. - Willis TX

International Classification:

E21B 19/16

US Classification:

166 7753, 81 5716, 81 5724, 166 774, 175 85

Abstract:

Drilling rig apparatus for connecting and disconnecting well pipe at a drilling rig. A remotely controlled power wrench assembly is mounted on a remotely controlled lifting mechanism attached to a base spaced about the well axis on the rig floor. The wrench assembly includes upper and lower wrenches carried by the lifting mechanism. The wrench assembly includes a lower wrench for gripping a lower box coupling of a drill pipe section at the well center. An upper wrench is provided for torquing and spinning an upper pin coupling into or out of threaded engagement with the lower box coupling. A manipulator is pivotably carried on a rod supported from the wrench assembly. The manipulator captures a drill pipe section and transfers the drill pipe section between the well axis and a position at the side of the wrench assembly. A slot is provided between frame members of the base for placement of a power slip manipulator for setting and releasing slips in the rotary table.

US Patent:

20130203179, Aug 8, 2013

Filed:

Apr 8, 2011

Appl. No.:

13/640344

Inventors:

Matthew J. Vincent - Kingwood TX, US
David L. Fletcher - Kingwood TX, US
Vijay Nanda - Houston TX, US

International Classification:

G01N 25/00

US Classification:

436147

Abstract:

Disclosed is a method for determining when to replace a guard bed material used to remove one or more catalyst poisons from a feed based on a parameter change in a process. A guard bed having a guard bed material is in fluid communication with a catalyst bed having a catalyst. At least three monitors are positioned in said guard bed or said catalyst bed and at least one parameter of the guard bed or catalyst bed is monitored. A feed component comprising one or more catalyst poisons is supplied to said guard bed or said catalyst bed. The feed is contacted with said guard bed material or said catalyst to remove at least a portion of a catalyst poison and to form a product which produces an increase or a decrease in said parameter. The monitored parameters are compared to determine when to replace the guard bed material.

US Patent:

20160187271, Jun 30, 2016

Filed:

Mar 7, 2016

Appl. No.:

15/062965

Inventors:

- Baytown TX, US
David L. Fletcher - Kingwood TX, US
Vijay Nanda - Houston TX, US

International Classification:

G01N 25/00
C10G 45/72
C07C 2/70
C10G 45/08

Abstract:

Disclosed is a method for determining when to replace a guard bed material used to remove one or more catalyst poisons from a feed based on a parameter change in a process A guard bed having a guard bed material is in fluid communication with a catalyst bed having a catalyst. At least three monitors are positioned in said guard bed or said catalyst bed and at least one parameter of the guard bed or catalyst bed is monitored. A feed component comprising one or more catalyst poisons is supplied to said guard bed or said catalyst bed. The feed is contacted with said guard bed material or said catalyst to remove at least a portion of a catalyst poison and to form a product which produces an increase or a decrease in said parameter. The monitored parameters are compared to determine when to replace the guard bed material.