Novel valve needle of pressure control drilling throttle valve

Abstract

The invention relates to a novel valve needle of a pressure control drilling throttle valve. The valve needle comprises a valve spool (1), a valve rod upper portion (2), a valve rod middle portion (3), a valve rod lower portion (4), a fluid passage (5), a cylindrical pin (6) and a lead filling area (11), stepped through holes are arranged along the axis direction of the valve spool (1), a transverse fluid passage (12) is arranged on the valve rod upper portion (2), the longitudinal fluid passage (5) arranged inside a valve rod is communicated with the transverse fluid passage (12), the valve rod lower portion (4) is connected with the valve spool (1) by means of threaded fit, the matched position of the valve spool (1) and the bottom end surface of the valve rod middle portion (3) is sealed by an O-shaped sealing ring (10), and the cylindrical pin (6) is inserted into a cylindrical pin groove. The valve needle has the advantages that the valve spool is made of YG8 alloy, the contour of the valve spool is machined in a numerically controlled manner according to a profile curve equation, the valve needle is high in machining accuracy, fine in abrasion resistance and erosion resistance, long in service life, fine in sealing performance and convenient to disassemble, and the valve spool is firmly connected with the valve rod.

Description

technical field [0001] The invention relates to the technical field of pressure-management drilling wellhead choke manifolds, in particular to a valve needle of a novel pressure-management drilling choke valve. Background technique [0002] Managed pressure drilling (MPD) is to control wellhead casing pressure in real time through MPD system equipment and technology, so as to realize precise control of bottom hole annular pressure during the whole process of drilling, single connection, tripping in and tripping out. The control of wellhead casing pressure is very important to managed pressure drilling. As a key component of wellbore pressure control, the pressure-controlled choke manifold controls the wellhead back pressure by generating adjustable chokes to realize drilling under static and dynamic conditions. The bottom hole pressure is relatively stable during the process, and the control of the wellhead back pressure is mainly reflected in the scientific design and accur...

AI Technical Summary

Problems solved by technology

The split connecting part adopted in the present invention connects the head and the tail, and the stopper rod is pressed into the central through hole of the connecting part. The connection is firm, but it is difficult to assemble and disassemble, and the stopper rod is forced into the connecting part When it is inside the central through hole, it is easy to cause the deformation of the connecting part, so that the coaxiality error between the head and the tail is large, the control accuracy is low, and it cannot meet the control pressure requirements of MPD

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