Patent ID: 7044229

Claim:
A downhole valve device ( 1 ) in a drill string ( 14 ) in a petroleum well ( 2 ) for adjusting the annular fluid velocity and wellbore pressure, comprising a valve housing ( 20 ) having connection means for connecting the valve housing between adjacent segments ( 12 , 13 ) of the drill string, the valve housing further comprising a longitudinal bore ( 22 ) forming an unimpeded fluid connection between the adjacent segments, the valve housing ( 20 ) being provided with at least one valve ( 23 ), located between longitudinal bore ( 22 ) and an annulus ( 3 ′, 4 ′) between the well ( 2 ) and the drill string ( 14 ), the valve ( 23 ) being caused to open and close to the flow of drilling fluid from the longitudinal bore ( 22 ) to the annulus ( 3 ′, 4 ′) between the well ( 2 ) and the drill string ( 14 ) by an actuator ( 27 ), said actuator ( 27 ) responding to a control device ( 28 ) connected to a sensor ( 30 ) that detects changes in downhole physical parameters or signals from the surface, the valve ( 23 ) of the downhole valve device ( 1 ) being further provided with means to permit even distribution of drilling fluid into the annulus.