AUTOMATIC CHOKE OPTIMIZATION AND SELECTION FOR MANAGED PRESSURE DRILLING

摘要

A choke valve assembly, system, and method can be used with a drill string in a wellbore to aid in controlling the bottom hole pressure during drilling of the wellbore. The choke valve assembly can have a primary choke and one or more supplemental chokes, where these choke valves each have a controllable range relative to the flow and pressure of drilling fluid passing through the assembly. A control unit can automatically actuate the primary choke and one or more supplemental chokes in order to both maintain the choke valves within their controllable ranges and concurrently maintain a consistent boom hole pressure in the connected wellbore.

主权项

1. A choke valve assembly, comprising:
a primary choke in fluid communication with an outlet; a secondary choke in fluid communication with the primary choke and the outlet; and a control unit operatively coupled to the primary choke and the secondary choke, wherein the control unit is programmed with instructions to automatically adjust the secondary choke to keep a coefficient of flow (Cv) of the primary choke within a primary choke controllable range.