RU2214499C2 - Ram-type blowout preventer (versions) - Google Patents

Abstract

FIELD: oil and gas producing industry, particularly, devices for wellhead sealing. SUBSTANCE: ram-type blowout preventer includes body with wellbore vertical channel and ram channel of annular cross-section with sealing members, with covers and drives provided from both sides of sealing members. There is hollow changeable member of prevented in form of open cylindrical insert with through holes in side cylindrical surface. Hollow changeable member is installed in bore of ram channel with through holes coaxial to wellbore channel. Provided on external side cylindrical surface of changeable member, along its guides, from two sides of wellbore channel are sockets for sealing members. Internal surface of cylindrical insert comes in contact surface of cylindrical insert comes in contact with rams. In the second version of preventer realization, channel for rams is rectangular in cross-section as distinguished from the first version and provided with sealing members. Covers and drives are provided from two sides of rams. Ram-type blowout preventer has changeable member in form of hollow open seat with sealing member. Cylindrical part of changeable member is located in sockets of vertical wellbore channel and serves for locking of changeable member. Flat oval part with hole coaxial to cylindrical part is located in ram channel bore with internal working cavity of flat oval shape in plane perpendicular to vertical axis of wellbore channel and serves for contact with rams. Cylindrical part of changeable member is locked by locking screws with conical ends coming in contact with conical recesses made in socket of preventer wellbore vertical channel. Tops of conical ends and conical recesses are located at different levels to provide for pressing of external flat oval part of changeable member to internal plane of bore of ram channel. Sealing member is located in socket made on external side surface of changeable member cylindrical part. EFFECT: increased duration of service cycle of preventer, and performance of repair of preventer damaged surfaces coming in contact with ram seals without dismantling the preventer from wellhead. 3 cl, 8 dwg

Description

 The invention relates to the oil and gas industry, and in particular to devices for sealing the wellhead in order to prevent emissions, and is used as part of a blowout equipment complex.

 A known preventer comprising a housing in which dies with seals and a drive are installed. The dies in the section are cylindrical, limited by the upper and lower semicircles eccentrically located relative to each other (1).

 The main reason for failure of preventers is damage to the surfaces of the preventer in contact with the seal dies. This applies both to preventers with ram channels of circular cross section, and to preventers with ram channels of rectangular cross section.

 The objective of the proposed technical solution is to increase the life cycle of the preventer and repair damaged surfaces of the preventer in contact with the ram seals without dismantling the preventer from the wellhead.

 This task is achieved by the fact that in the known blowout preventer, the preventer, including a housing with a vertical barrel channel and a die channel with sealing elements, covers and actuators are provided on both sides, the die channel has a circular cross section, the preventer further comprises a hollow interchangeable element in the form of an open a cylindrical insert with through holes in the lateral cylindrical surface mounted in the bore of the ram channel through holes in alignment with the stem channel, at the same time, on the outer lateral cylindrical surface of the replaceable element along its guides on two sides of the vertical barrel channel, nests for sealing elements are provided, and the inner surface of the cylindrical insert is in contact with the dies.

где a = 0,01745 • (r + d/2) • arcsin R/r,
d - диаметр сечения уплотнительного кольца;
k = f(P_p) - коэффициент, характеризующий степень деформации уплотнительного кольца (Р_р - рабочее давление превентора).In addition, in a blowout preventer ram preventer, the sealing elements of the cylindrical insert can be made in the form of interchangeable rings, while the position of the points lying on the midline of the bottom of the socket under the sealing element is determined by the dependence
φ = arcsinR / r • cosα,
where r is the radius of the bottom of the nest;
R is the radius of the nest along the midline in projection onto a plane passing through the X, Y axis, perpendicular to the Z axis;
α and φ are the current value of the angle of the radius vector connecting the center of the coordinate axes (point O) with point A lying on the midline of the bottom of the socket under the sealing element, and determining its position in the projections on the XY and YZ plane, respectively, and the average diameter of the sealing element is selected from the ratio

where a = 0.01745 • (r + d / 2) • arcsin R / r,
d is the diameter of the cross section of the sealing ring;
k = f (P _p ) is a coefficient characterizing the degree of deformation of the sealing ring (P _p is the working pressure of the preventer).

 In the second embodiment, in the known blowout preventer, the preventer includes a housing with a vertical stem channel and a ram channel with sealing elements, covers and actuators are provided on both sides of the ram, the ram channel has a rectangular section, the preventer additionally contains a replaceable element in the form of a hollow open saddle with by a sealing element, the cylindrical part of the replaceable element is located in the socket provided in the vertical barrel channel and serves to fix the replaceable element ment, and its flat-oval part with a hole coaxial to the cylindrical part, is located in the bore provided in the ram channel with the inner working cavity of the flat-oval shape in the plane perpendicular to the vertical axis of the barrel vertical channel, and serves to contact the rams, while the cylindrical part of the replaceable element is fixed locking screws with conical ends in contact with the conical sharpeners made in the socket of the vertical barrel of the preventer, and the tops of the horses eskih endings and conical sharpening at different levels to enable the compression of the outer part of the flat oval replacement element to the inner bore plane spot channel, and the sealing member is disposed in a nest formed on the outer side surface of the cylindrical part of the replacement element.

In FIG. 1 shows a preventer with a die channel of circular cross section; FIG. 2 - a preventer with a spot channel of rectangular cross section; figure 3 - the attachment of the removable element in the preventer with a spot channel of rectangular cross section; figure 4 - the implementation of the nest under the seal of the replaceable element along the axes XZ for the preventer with a ram channel of circular cross section; in FIG. 5 - the implementation of the nest under the seal of the replaceable element along the YZ axes for the preventer with a die channel of circular cross section; 6 is a section BB of FIG. 4; Fig.7 - sealing element of a removable element; on Fig - replacement element for the preventer with channels of rectangular cross-section (R _{with the} radius of the flat oval part of the replacement element; D _{with the} diameter of the cylindrical part of the replacement element, e is the eccentricity).

 A blowout preventer consists of a housing 1, covers 2, drives 3, a vertical stem channel 4, a circular cross-section channel 5 for dies 6 (shown in the closed position in FIG. 1) with sealing elements 7 and a hollow interchangeable element made in the form of a hollow open a cylindrical insert (sleeve), with through holes in the lateral cylindrical surface located in the bore of the ram channel 5 on two sides of the barrel channel 4. When installing the through hole of the replaceable element, alignment is established ovomu channel.

 The boring in the die channel is made in such a way that the inner (working) surface of the replaceable element is a continuation of the die channel.

 On the outer lateral cylindrical surface of the replaceable element 8 along its guides on two sides of the barrel channel 4, sockets 9 are provided for the sealing elements 10, which can be made in the form of rings. Locking fonts 19 fix the replaceable element in the axial direction and insure it against rotation.

The sockets 9 in the replacement element for the sealing elements 10 in the blowout preventer with a ram channel of circular cross section are made so that the position of points A lying on the midline 11 of its bottom 12 is determined by the dependence
φ = arcsinR / r • cosα,
where r is the radius of the bottom of the nest;
R is the radius of the nest along the midline in projection onto a plane passing through the X, Y axis, perpendicular to the Z axis;
α and φ are the current value of the angle of the radius vector connecting the center of the coordinate axes (point O) with point A and determining its position in the projections on the XY and YZ planes, respectively.

The sealing element 10 is made of rubber or a polymer material, the average diameter of which is determined from the ratio
D _y = k [1,5 (a + R) - a R],
where a is the diameter of the cross section of the sealing element;
k = f (P _p ) is a coefficient characterizing the degree of deformation of the sealing element (P _p is the working pressure of the preventer).

 The second embodiment of a blowout preventer includes a housing 1, covers 2, actuators 3, a vertical stem channel 4, a rectangular channel 13 for dies 14 (shown in the closed position in FIG. 2) with sealing elements 15 and a replaceable preventer element made in the form a hollow open saddle (for example, a tee), the cylindrical part 16 of which serves to fix the replaceable element in the vertical stem channel 4, and the plane-oval part 17 perpendicular to it with the hole coaxial to the cylindrical 16, is mounted ovana in the bore (socket) provided in the channel 13 for contact with the dies 14 along its inner surface.

 The cylindrical part 16 of the replaceable element is coaxial with the barrel channel and is fixed against rotation and axial displacement by the locking screws 18 with conical ends evenly located in the cylindrical part of the replaceable element with the possibility of contacting with the conical sharpeners 21 made in the socket of the barrel channel 4 of the preventer, while the vertices of the conical ends and conical sharpenings are located at different levels, which makes it possible to tighten the outer rectangular part of the replaceable element to the surface and boring ram channel 13.

 The bores in the spot channel 13 and the stem channel 4 are made in such a way that the inner surfaces of the replaceable element are a continuation of the spot channel and the stem, respectively.

 The major axis 24 of the inner working part 22 of the interchangeable element in contact with the dies is oriented along the ram channel 13 (FIG. 2) and is aligned with it.

 On the outer side surface of the cylindrical part of the removable seat along its guide, a socket 25 is provided for the sealing element 26.

 A method of manufacturing the socket 9 in the replaceable element 8 is that according to the calculated coordinates X, Y, Z of the points of the midline of the bottom of the groove and the rotary coordinate, a program is compiled for processing the sleeve on the CNC machine.

 Replacing a replaceable element in a blowout preventer with a round die channel is carried out as follows: undock the covers, remove the locking pins 19, remove the replaceable element from the boring of the die channel, install a new replaceable element, fix it with pins and mount the covers.

 Replacement of the replaceable element in a blowout preventer with a rectangular die channel is carried out as follows: first, the locking screws 18 (Fig. 3) that hold the replaceable element are unscrewed, remove it through the ram channel 13 (Fig. 2), and then a new replaceable element is installed and fixed its locking screws 18 (Fig. 3).

 The implementation of the proposed technical solution will allow the working (internal) surfaces of the replaceable elements to give the necessary (unlike the entire body) properties required in operation: wear and corrosion resistance, resistance to scoring, strength, low coefficient of friction, etc. This, in turn, It will save expensive high-alloy steels, which would be necessary for the manufacture of the entire body, and when using the proposed proposal only for the manufacture of replaceable elements.

Sourse of information
1. RF patent 2111336, MKI 6 E 21 V 33/06, publ. 05/20/98

Claims (3)

 1. Blow-out ram preventer comprising a housing with a vertical barrel channel and a ram channel with sealing elements, covers and actuators are provided on both sides, characterized in that the ram channel has a circular cross section, the preventer further comprises a hollow interchangeable element in the form of an open cylindrical insert with through holes in the lateral cylindrical surface mounted in the bore of the ram channel through holes through coaxial with the stem vertical channel, while Outer lateral cylindrical surface of the replaceable element along its guides on both sides of the vertical barrel is provided with nests for sealing elements, and the inner surface of the cylindrical insert is in contact with the dies. 2. Blowout preventer ram according to claim 1, characterized in that the sealing elements of the cylindrical insert are made in the form of interchangeable rings, while the position of the points lying on the midline of the bottom of the socket under the sealing element is determined by the dependence:
φ = arcsinR / r • cosα,
where r is the radius of the bottom of the nest;
R is the radius of the nest along the midline in projection onto a plane passing through the X, Y axis. Perpendicular to the Z axis;
α and φ are the current value of the angle of the radius vector connecting the center of the coordinate axes (point O) with point A lying on the midline of the bottom of the socket under the sealing element, and determining its position in the projections on the XY and YZ planes, respectively
and the average diameter of the sealing element is selected from the ratio

where a = 0.01745 • (r + d / 2) arcsin R / r;
d is the diameter of the cross section of the sealing element;
k = f (P _p ) is a coefficient characterizing the degree of deformation of the sealing element (P _p is the working pressure of the preventer).  3. A blowout preventer, including a housing with a vertical stem channel and a die-glass with sealing elements, covers and actuators are provided on both sides, characterized in that the ram channel has a rectangular cross-section, the preventer additionally contains a replaceable element in the form of a hollow open saddle with by a sealing element, the cylindrical part of the replaceable element is located in the socket provided in the vertical barrel channel and serves to fix the replaceable element, and its flat the main part with the hole coaxial with the cylindrical part is located in the bore provided in the die channel with the internal working cavity of the flat oval shape in the plane perpendicular to the vertical axis of the vertical barrel and serves to contact the dies, while the cylindrical part of the replaceable element is fixed with locking screws with conical ends in contact with conical sharpeners made in the nest of the vertical stem of the channel of the preventer, and the vertices of the conical ends and conical sharpenings are located at different levels to provide the possibility of pressing the outer flat oval part of the replaceable element to the inner plane of the bore of the die channel, and the sealing element is located in the socket made on the outer side surface of the cylindrical part of the replaceable element.

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