Darrell W Johnson

US Patent:

7178600, Feb 20, 2007

Filed:

Feb 20, 2004

Appl. No.:

10/783982

Inventors:

Mike A. Luke - Houston TX, US
Tom Fuller - Insch, GB
Darrell Johnson - Katy TX, US
David Brunnert - Cypress TX, US
Brian Grayson - Sugar Land TX, US
David Pavel - Kingwood TX, US
R. K. Bansal - Houston TX, US

Assignee:

Weatherford/Lamb, Inc. - Houston TX

International Classification:

E21B 34/10

US Classification:

166373, 166316, 166319, 1663328, 166375

Abstract:

Methods and apparatus for utilizing a downhole deployment valve (DDV) to isolate a pressure in a portion of a bore are disclosed. Any combination of fail safe features may be used with or incorporated into the DDV such as redundant valve members, an upward opening flapper valve or a metering flapper below a sealing valve. In one aspect, a barrier or diverter located in the bore above a valve member of the DDV permits passage through the bore when the valve member is open and actuates when the valve member is closed. Once actuated, the barrier or diverter either stops or diverts any dropped objects prior to the dropped object reaching and potentially damaging the valve member. In another aspect, the tool string tripped in above the DDV includes an acceleration actuated brake that anchors the tool string to a surrounding tubular if the tool string is dropped.

US Patent:

7278497, Oct 9, 2007

Filed:

Jul 9, 2004

Appl. No.:

10/888558

Inventors:

Jim Terry - Houston TX, US
Tom Bailey - Houston TX, US
Adrian Vuyk - Houston TX, US
Alejandro Coy - Katy TX, US
Ron Divine - Humble TX, US
Darrell Johnson - Katy TX, US

Assignee:

Weatherford/Lamb - Houston TX

International Classification:

E21B 7/04

US Classification:

175 61, 175 70

Abstract:

The present invention generally provides an inexpensive method for drilling a multilateral wellbore where the pressure exerted on a formation of interest by a column of drilling fluid may be controlled. In one aspect, a method for drilling a lateral wellbore from a main wellbore is provided, including running a string of casing with an injection line connected thereto into the main wellbore, wherein the injection line is disposed along an outer side of the casing and a portion of the casing corresponding to a starting depth of the lateral wellbore is made from a drillable material; running a drillstring through the casing to the starting depth of the lateral wellbore, wherein the drillstring comprises a drill bit; injecting drilling fluid through the drill sting; and injecting a second fluid, having a density less than that of the drilling fluid, through the injection line at a rate corresponding to an injection rate of the drilling fluid to control hydrostatic pressure exerted by a column of the drilling fluid and the second fluid returning through the casing.