Patent ID: 8607873

Claim:
A device configured to control a fluid flow between a petroleum reservoir ( 6 ) and a pipe body ( 2 ), wherein an inflow chamber ( 10 ) is provided externally of the pipe body ( 2 ) and attached to or integral with the pipe body ( 2 ), the inflow chamber being interactive with a flow controller ( 50 ), wherein the flow controller ( 50 ) is inserted into the inflow chamber ( 10 ) from a region thereof closest to the petroleum reservoir ( 6 ) and thereby closing the chamber ( 10 ) thereat, wherein a wall of the inflow chamber ( 10 ) has a fluid flow restriction ( 18 ) in communication with a borehole ( 4 ) annulus ( 14 ) between the reservoir ( 6 ) and the pipe body ( 2 ), the flow restriction ( 18 ) being interactive with the flow controller ( 50 ), wherein the inflow chamber ( 10 ) communicates with an interior of the pipe body ( 2 ) via a valve seat ( 22 ) inserted in the pipe body ( 2 ), the valve seat ( 22 ) having a through-going valve opening ( 20 ), wherein the flow controller ( 50 ) has a cylinder ( 32 ) and a piston ( 26 ) movable inside the cylinder, the piston ( 26 ) having a first or closing side ( 34 ) facing in a direction of the reservoir ( 6 ) and a second or opening side ( 40 ) facing in a direction of the pipe body ( 2 ), wherein the piston ( 26 ) is spring-loaded by a spring ( 42 ) extending between a bottom region of the cylinder ( 10 ) and said second side ( 40 ) of the piston, the bottom region having an opening, wherein the second side ( 40 ) of the piston ( 26 ) has a piston rod surrounded by the spring ( 42 ), wherein a valve body ( 24 ) is attached to the piston rod, the valve body ( 24 ) being configured to interact with said valve seat ( 22 ) to control flow rate through the valve opening ( 20 ), said valve body ( 24 ) and said valve seat ( 22 ) being interactive with the flow controller ( 50 ), wherein a first end of the cylinder ( 32 ) closest to the reservoir ( 6 ) is sealed off by a first diaphragm ( 44 ), and the cylinder bottom region opening being sealed off by a second diaphragm ( 46 ), the valve body ( 24 ) extending through the second diaphragm ( 46 ) in a sealed manner, wherein a face of the first diaphragm ( 44 ) which faces away from an interior of the cylinder ( 32 ) is in communication with the annulus ( 14 ), and wherein alterations of any pressure difference (ΔP) between a pressure (Pr) from the reservoir ( 6 ) and a pressure (Pt) in the pipe body ( 2 ) and in the inflow chamber ( 10 ) act on said first and second diaphragms ( 44 , 46 ) to control movement of the piston ( 26 ) within the cylinder ( 32 ) and thereby a location of the valve body ( 24 ) relative to the valve seat ( 22 ) to yield a specific fluid flow rate through the valve opening ( 20 ).