CPC E21B 7/15 (2013.01) [E21B 21/08 (2013.01)] | 19 Claims |
1. A downhole mixer comprising:
a housing having an uphole end and a downhole end;
a channel to convey a drilling fluid through the housing, the channel including an entrance proximate the uphole end and an exit proximate the downhole end; and
a flow restrictor positioned in the channel between the entrance and the exit, wherein the flow restrictor comprises an elongational flow orifice having a fixed diameter at one end of the elongational flow orifice to manage an electrical property of the drilling fluid by creating a pressure drop between the entrance and the exit to increase shear stress in the drilling fluid;
wherein the elongational flow orifice has a length L and at least a first diameter D1, a second diameter D2, and an average inner diameter D, wherein the length L is at least two times the average inner diameter D.
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