US 11,851,991 B2
Downhole concentric friction reduction system
John M. King, Conroe, TX (US); Daniel Hernandez, Jr., Pasadena, TX (US); James R. Streater, Jr., Humble, TX (US); and Paul Oberlin, Houston, TX (US)
Assigned to National Oilwell Varco, L.P., Houston, TX (US)
Filed by National Oilwell Varco, L.P., Houston, TX (US)
Filed on Oct. 8, 2021, as Appl. No. 17/496,896.
Prior Publication US 2023/0111289 A1, Apr. 13, 2023
Int. Cl. E21B 41/00 (2006.01); E21B 34/06 (2006.01)
CPC E21B 41/00 (2013.01) [E21B 34/06 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A friction reduction system disposable in a wellbore, comprising:
a first valve member comprising an inner surface which comprises a valve seat extending arcuately between a pair of opposed flanking surfaces whereby the valve seat defines a channel that extends arcuately from a first of the pair of flanking surfaces to a second of the pair of flanking surfaces; and
a second valve member rotatable concentrically about a central axis of the first valve member and comprising a central passage and a radial port coverable by the valve seat of the first valve member;
wherein the friction reduction system comprises an open configuration in which fluid communication is established between the central passage of the second valve member and the arcuate channel, the open configuration providing a maximum flow area through a valve of the friction reduction system comprising the second valve member and the first valve member;
wherein the friction reduction system comprises a closed configuration in which fluid communication is restricted between the central passage of the second valve member and the arcuate channel, the closed configuration providing 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.