METHOD AND APPARATUS FOR PRECISE CONTROL OF WELLBORE FLUID FLOW.

摘要

A method for controlling flow of fluid from an annular space in a wellbore includes changing a flow restriction in a fluid flow discharge line from the wellbore annular space. The flow restriction is changed at a rate related to a difference between at least one of a selected fluid flow rate out of the wellbore and an actual fluid flow rate out of the wellbore, and a selected fluid pressure in the annular space and an actual pressure in the annular space.