RU2264529C1 - Preventer - Google Patents

Abstract

FIELD: bottomhole equipment used for underground oil and gas well repair, for sealing well head in emergency and during long operation interruption.

SUBSTANCE: preventer has body with axial channel, pipe rams for sealing pipes to be lowered in well through above axial channel, blind rams for sealing axial channel in the absence of pipes in the well. Composite, namely hydraulic and manual ram drive is made as hydraulic cylinder with high-pressure and low-pressure compartments and piston with screw rod. Piston has channel to establish communication between high-pressure and low-pressure compartments. The channel is provided with bypass valve made as a slide spring-loaded from both sides. Value of spring power and width of gap between slide and seat orifice of the piston are chosen to provide free working liquid flow from one compartment into another one in "manual drive" mode. In "hydraulic drive" mode slider may move in one of its extreme positions under the action of dynamic head in liquid at hydraulic cylinder inlet so that slider closes above channel in the piston.

EFFECT: increased ability of manual ram driving.

9 dwg

Description

The invention relates to equipment used in the underground repair of oil and gas wells, and is used to seal the mouth in the event of an emergency at the well, as well as during a long break in work.

Known preventer containing a housing with an axial channel, hydraulic dies for sealing pipes that are lowered into the well through the axial channel, blind dies with hydraulic drives for sealing the axial channel in the absence of pipes in the well, a screw rod used to manually drive dies in the event of a hydraulic failure or fixing dies after moving them to the "closed" position [1]. A disadvantage of the known preventer is the lack of a bypass channel of the working fluid from the cavities of the hydraulic cylinder. When moving the piston with a manual screw rod, the entire volume of the working fluid occupied by the hydraulic cylinders will flow through the remote hoses through the hydraulic system of the power unit. With a considerable length of the remote hoses and at low ambient temperatures in the winter season, manual control of the dies with pumping of the thickened working fluid becomes a very problematic procedure.

Also known is a preventer containing a housing with an axial channel, hydraulic dies for sealing pipes that are lowered into the well through the axial channel, blind dies with hydraulic drives for sealing the axial channel in the absence of pipes in the well, a screw rod used to manually drive dies in the event of a hydraulic failure or fixing the dies after moving them to the closed position [2]. A disadvantage of the known preventer is also the lack of a bypass channel of the working fluid from the cavities of the hydraulic cylinder and with the problems of manual drive dies described above.

The technical problem solved by the invention is to facilitate the manual drive of the dies.

The problem is solved in that the preventer containing a housing with an axial channel, pipe dies for sealing pipes that are lowered into the well through an axial channel in the housing, dies for sealing the axial channel in the absence of pipes in the well, combined (hydraulic and manual) dies drive, made in the form of a hydraulic cylinder with a piston equipped with a screw rod, made so that the piston is equipped with a communication channel for cavities of high and low pressure with a bypass valve, made, for example, in the form of a movable gold ka, which is in the open position in the BOP mode "manual drive" and "hydraulic" mode in the closed position.

The invention is illustrated by drawings, which depict:

In Fig.1 is a General view of the preventer in the "hydraulic drive" mode.

Figure 2 is a General view of the preventer in the mode of "manual drive".

Figure 3 is a side view of a preventer along AA (without steering wheels).

Figure 4 is a horizontal section along BB.

Figure 5 - fragment In a horizontal section along BB in the "hydraulic drive" mode.

Figure 6 - fragment In a horizontal section along BB in the mode of "manual drive".

7 is a view of G; a cross-sectional piston with an image of the communication channel of the high and low pressure cavities with the bypass valve in the open position in the "manual drive" preventive mode.

In Fig.8 is a view of; a cross-sectional piston with an image of the communication channel of the high and low pressure cavities with the bypass valve in the closed position in the "hydraulic drive" preventive mode when the working fluid is supplied from the bottom up.

Figure 9 is a view of G; a cross-sectional piston with an image of the communication channel of the high and low pressure cavities with the bypass valve in the closed position in the "hydraulic drive" preventive mode when the working fluid is supplied from top to bottom.

The preventer comprises a housing 1 with an axial channel 2 for pipe passage (not shown), pipe dies 3, blind dies 4, side covers 5 with a hydraulic actuator made in the form of a hydraulic cylinder 6, a piston 7, a rod 8, a screw 9 and a helm 10 (Fig. 1). To the fittings 11 are connected hoses from the energy block (figure 2). The fittings 11 are connected by communication channels with the working cavities of the hydraulic cylinders 6, made in the housing 1 and the side covers 5. The piston 7 is equipped with a communication channel 12 of the high and low pressure cavities with an overflow valve made, for example, in the form of a spool 13 spring-loaded on both sides by springs 14 (Fig.7). The end surfaces of the spool 13 are alternately in contact with the gaskets 15, depending on the direction of supply of the working fluid. The magnitude of the force of the springs 14, the cross section of the communication channel 12 and the gap between the spool 13 in the bore of the piston 7 are selected so that in the "manual drive" mode, the working fluid freely flows through the gap of the spool 13 from one cavity of the hydraulic cylinder 6 to another and back, and in the "hydraulic drive" mode, the working fluid would move the spool 13 to one of the extreme positions, depending on the direction of its supply.

The preventer works as follows.

In the "manual drive" mode (Figs. 2; 6 and 7), the piston 7 receives forced movement from the rod 8 when the screw 9 is rotated by the hand wheel 10. The piston 7 slowly moves to the center of the preventer, the working fluid freely flows through the message channel 12 and the gap between the spool 13 in the bore of the piston 7. Thus, the piston moves in the hydraulic cylinder 6, passing through the communication channel 12 the working fluid from one cavity of the hydraulic cylinder 6 to another. However, the working fluid does not create significant resistance to the movement of the piston 7.

In the "hydraulic drive" mode (Figs. 1, 5, 8 and 9), the piston 7 moves under the influence of a high-speed pressure of the working fluid entering the hydraulic cylinder 6 at high pressure (up to 14 MPa). With such an intense pressure, the spool 13 moves to the extreme position against the gasket 15 and blocks the communication channel 12. The piston 7 performs a complete hydraulic actuating cycle. When changing the direction of supply of the working fluid to the hydraulic cylinder 6, the described process is repeated, but with the movement of the spool 13 in the opposite direction.

The advantage of the inventive preventer is the ease of control of the preventer in the "manual drive" mode by communicating the cavities of the hydraulic cylinder through the communication channel in the piston.

Sources of information

1. Composite catalog of oil and gas equipment and services. The third issue, under the leadership of V.Yu. Krasik, A.D. Kuzmina. Publishing house "Fuel and Energy", M. 1998, p. 501.

2. 1995-96. Composite catalog of oil and gas equipment and services. Volume 1. Published by Gulf Publiching Company. Publishing house "Fuel and Energy", M. 1998, p. 415.

Claims (1)

A preventer containing a housing with an axial channel, pipe dies for sealing pipes that are lowered into the borehole through an axial channel in the housing, blind dies for sealing the axial channel when there are no pipes in the well, combined hydraulic and manual dies drive made in the form of a hydraulic cylinder with high cavities and low pressure and a piston with a helical rod, characterized in that the piston has a communication channel for cavities of high and low pressure, equipped with an overflow valve in the form of a slide valve, spring-loaded with two springs, and the magnitude of the force of the springs and the size of the gap between the spool and the bore of the piston are selected with the possibility of free flow of the working fluid from one cavity to another in the "manual drive" mode, and in the "hydraulic" spool under the influence of the high-speed pressure of the working fluid coming in the hydraulic cylinder, has the ability to move to one of the extreme positions and overlap the communication channel of the cavities.

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