National Oilwell Varco, L.p.

Daniel Hernandez, Jr

James Robert Streater

Jose Saldana

Francisco Tejada, Jr

Filiberto Garcia

Paul Victor Oberlin

John Matthew King

Josefat Rodriguez-Estrada, Jr

James R Streater

A friction reduction system disposable in a wellbore includes a first valve member including an inner surface which includes a valve seat; and a second valve member rotatable concentrically about a central axis of the first valve member and including a radial port coverable by the valve seat of the outer valve member, wherein the friction reduction system includes an open configuration that provides a maximum flow area through a valve of the friction reduction system including the second valve member and the first valve member, wherein the friction reduction system includes a closed configuration that provides a minimum flow area through the valve which is less than the maximum flow area, and wherein the friction reduction system is configured to generate a pressure pulse in a fluid flowing through the friction reduction system in response to the friction reduction system transitioning from the open configuration to the closed configuration.

Downhole concentric friction reduction system

Provided is a safety joint with a moveable seal designed to prevent hydrostatic locking. The safety joint is primarily made up assembling a pin end having a first seal, a threaded connection, and a second, moveable seal to a box end. The moveable seal is disposed in a recess formed in the pin end and includes an O-ring and a spring. When the safety joint is assembled downhole, a volume of fluid may become trapped between the first seal and the second seal. The trapped fluid in turn pushes the O-ring towards the spring, thereby limiting pressure build-up by substantially maintaining the volume trapped between the first and second seals.

Safety joint designed with anti-lock pressure compensation seal

A grapple for use in an overshot has a tension ring with a reduced helix diameter. However, the helix diameter is not reduced on either sides of the control finger slot to allow the grapple to remain in contact with the control. In the alternative, a composite helix member may be utilized. Another embodiment comprises the inclusion of expansion blades on the inner diameter ('ID') of the tension ring which allow the grapple to expand substantially before the fish reaches the segments. Another embodiment provides for a control with an offset finger to allow the guide thread ID to be smaller than the bowl helix major ID. Yet another embodiment provides a spiral grapple having grooves along its axis to provide the ability to catch a larger range of fish.

Assembly and method for wide catch overshot

A grapple for use in an overshot has a tension ring with a reduced helix diameter but the helix diameter is not reduced on either sides of the control finger slot. One embodiment includes expansion blades on the inner diameter ('ID') of the tension ring to allow the grapple to expand substantially before the fish reaches the segments. An embodiment provides for a control with an offset finger to allow the guide thread ID to be smaller than the bowl helix major ID. Also provided is grapple control for a spiral grapple that has at least one gap to allow the grapple control to be more compliant during fishing operations. The control may include one or more bridges of reduced thickness. Alternate embodiments include gaps and support bands with or without bridges and/or a backup ring to help eliminate misalignment of the grapple control with the support shoulder of the overshot guide.

A three-ring seal assembly is provided to seal across extrusion gaps of varying size when used during down hole fishing operations.

Growing community of inventors

Pasadena, TX, United States of America

Daniel Hernandez, Jr