RU2013519C1 - Universal preventer - Google Patents

Abstract

FIELD: oil and gas producing industry. SUBSTANCE: device includes sealing members located on two levels and having a gate chamber between them. Blind and pipe rams, sealing rings with spring clamps or clamping rings, and traditional sealing rings are employed in various combinations as the sealing member. EFFECT: enlarged operating capabilities. 4 cl, 7 dwg

Description

 The invention relates to drilling equipment and is intended for sealing wellheads for all purposes.

 The closest analogue is the application N 4.747.447, in which dies "pipe" or "deaf" are located as sealing elements, located at the same level - in the lower part of the preventer, which can be called "die sump". The dies are driven by a hydraulic motor consisting of a cylinder, which is a continuation of the crankcase of the ram and collet piston, in the form of a truncated hollow cone with a hollow rod, the inner diameter of which is the bore diameter of the preventer. In the upper part of the casing, which is a continuation of the cylinder, which can be called a “lock case”, an automatic screw-slotted stop is placed, eliminating arbitrary depressurization of the well.

 Each of the crankcases occupies approximately half the height of the preventer housing.

 The removal of the dies from the axis of the preventer towards its walls, necessary for the passage of the bit, is provided only automatically by the springs. Therefore, when they seize, they may remain in the "preventer closed" position, which will be an obstacle to the passage of the bit. Washing of the dies, the die housing and the column is not provided. The use of other types of sealants, except dies, is excluded. If it is necessary to lock the coupling connection of the string, it is necessary to use a second preventer that increases the construction height of the wellhead strapping and the cost of strapping.

 As a prototype, application N 4.747.447 was adopted, the characteristic and criticism of which is given above.

 The second sinal is accepted a. with. USSR N 1.592.472 under the name "Preventor", in which a traditional cuff in the form of a hollow truncated cone is adopted as a sealant, containing in its cavity an axially movably planted cone-expander, designed to increase the diameter of the wellhead sealing part of the cuff when turning and hoisting column operations during the absence of a pressure above the atmospheric pressure under the preventer. The use of a cone-expander provides the ability to increase the durability of the cuff hundreds or thousands of times, compared with US patent N 2.170.915, N 3.965.987 and a. with. USSR N 309.116. A spring bracelet is placed on the lower outer end of the cuff, designed to force it to the column in those cases when, as a result of exposure to high or low temperatures, it loses its physical properties of self-clamping to the column; when the cuff has already undergone significant wear and even at nominal temperature forms a gap with the column, which completely eliminates its further use. However, a spring bracelet gives a good effect when used on cuffs exposed to high temperatures, for which it was created. With a chilled cuff or cuff made of a material of increased hardness, the spring bracelet does not achieve its goal.

 Replacement of the named preventers in extreme conditions is very dangerous and prohibited by law.

The purpose of the invention is to increase the reliability of sealing wells, expanding the range of applications, the possibility of emergency and safe alignment with the axis of the well, landing on the jig, automatic locking of the mating flanges of the jig and preventer (equipped with the same or different type of sealing elements) in extreme conditions,
Positive effect:
- a significant reduction in financial, material and labor costs for preparatory, final and regular operational operations. In addition, a full guarantee is provided for the exact alignment of the preventer with the well, its docking with the conductor, followed by the automatic locking of their flanges on the gushing well with complete safety for maintenance personnel;
- in the rational use of energy, which drives the sealing elements when it comes from a pump of constant performance. The positive effect is low cost and significantly higher reliability of a constant-flow pump versus a variable-speed pump, an almost uniform load of its drive from the beginning of the sealing process to its completion with the maximum reduction in time and energy for sealing the well;
- in providing the ability to lock coupling joints of the pipe string. Positive effect: elimination of the need to use a second preventer, and consequently, an increase in the construction height of the wellhead harness, a significant increase in operational efficiency and a decrease in the cost of work and wellhead strapping, an increase in the preventer resource by 100%;
- the possibility of automatic locking of the sealing elements against arbitrary depressurization of the wellhead. Positive effect: elimination of emergency release of fluid onto the surface, and consequently, elimination of injuries to maintenance personnel and preservation of the ecological regime;
- the possibility of pacing the sealing elements and cleaning the cavity of the preventer and the pipe string from amorphous and sticking sludge. Positive effect: eliminating the possibility of jamming mechanisms, increasing the durability of the actual sealing elements and improving the quality of sealing;
- the possibility of using hardened or steamed by the action of high temperatures of the cuffs (which are a hollow truncated cone made of elastic material or cuffs worn to form an annular gap between them and a worn pipe string. Moreover, the cuffs are rejected due to wear only of their wellhead, which interacts with a pipe string, which makes up only a fraction of% of its weight, and the remaining part, which has been completely preserved, is destroyed. itsitneyshih cuffs that are made of expensive rubber on the basis of imported components.

 The aim of the invention is the creation of a preventer with a technical characteristic that significantly exceeds the technical characteristic of the prototype of domestic and world analogues.

 Actually expected final positive effect: two- or four-fold increase in durability; its legal and safe use in extreme conditions; high versatility provided by twenty-five layout options; the possibility of locking couplings; high manufacturability at low labor costs.

 The invention and its distinctive (from the prototype and analogue) features is that it is made in a double-locking version and pivotally mounted on the conductor. Automatically centered with it and automatically stops. Its easily replaceable sealing elements (dies, cuffs or lentil rings) are located in the lower and upper crankcases with a sluice gap between them of at least the length of the coupling connection of the column. A double-acting piston block is built into the airlock, representing two hollow truncated cones of a collet piston symmetrically paired with a hollow rod. The inner sections of the collet pistons interacting with the rams are outlined by a curved line, the tangent lines in different sections of which form variable angles with the rams and the axis of the preventer: at the beginning of the sealing stroke, when small forces are required to move the rams - the angles are maximum, and at the end, when a large force is required to press the dies to the column, the angles are minimal. On the outer conical surfaces of the collet pistons ring ratchets are machined. With the mentioned angles of the ring ratchet, the locking dogs interact with the angles corresponding to the angles of the ring ratchet. They are movably seated in the housing perpendicular to its axis and pivotally connected to the spring-loaded two-arm lever of their asynchronous (dogs) turning on and off. The dies are mounted on the splines of the gear shaft, which are in rotational interaction with their gears.

 They are equipped with axial and radial channels for intensive cleaning of the cavities of the preventer. At the output end of one of the pinion shafts there is a lever for walking the dies and hydropercussion removal of amorphous and sticking sludge from the cavities of the preventer. Additional crimping of the cuff around the column is carried out by using a crimping ring with a conical bore, covering the outer wellhead of the cuff remotely attached to the end of the collet piston and axially movable with it.

 In FIG. 1 shows a preventer, layout option 1 with two rows of dies, vertical section. Collet piston in neutral position. To the left of the main axis of the die of the lower and upper rows and to the right of the axis - the upper die - are open for the passage of the bit. To the right of the axis, the lower plate is in contact with the column, sealing the wellhead, which is achieved by displacing the collet block-piston to the lower position.

 In FIG. 2 shows a preventer, in the plane of the axes carrying the dies, a horizontal section.

 In FIG. 3 is a preventer of embodiment II of the arrangement, the upper part of which is provided with dies in the position as in FIG. 1, a vertical section. Its lower part is equipped with a cuff sealant and a spring bracelet for pressing it to the column. To the left of the axis - the well is sealed. To the right is depressurized.

 In FIG. 4 is a preventer of embodiment III of the arrangement, the upper part of which is provided with dies in the position as in FIG. 1, a vertical section. Its lower part is equipped with a cuff sealant and an annular device for clamping it to the column. To the left of the axis - the well is sealed. To the right is depressurized.

 In FIG. 5 is a preventer of embodiment IV of the arrangement, the upper part of which is provided with dies in the position as in FIG. 1, a vertical section. The lower part is provided with a sealant in the form of a lentil ring of elastic material. To the left of the axis is the passage open for broaching the column. To the right - the well is sealed.

 In FIG. 6 shows a hinged landing of a preventer on a conductor; in FIG. 7 - locking mechanism of the flanges of the preventer and the conductor.

 Layout I (Fig. 1) - the preventer die (double-locking) contains as sealing elements two sets of dies located at two levels that are simultaneously included in the work. Dies can be "pipe" designed to seal columns of constant or variable diameters. In another case, one set of dies may be “pipe”, the second - “deaf”. The distance H1 between the lower and upper sets of dies is taken to be not less than the length of the sleeve connection of the pressurized column. This ensures its locking. The number of dies in each set is advisable to take three. Such expediency is proved by basic research. With three dies in one set, their durability and sealing quality significantly increase. In addition, it creates the possibility of using sealing materials as a lining of dies, reduced elasticity, with high performance, including heat resistance.

 The described arrangement I of the arrangement is suitable for operation in any spatial position. Any end of it can dock with the downstream object of the wellhead harness.

To drive the dies, a liquid or gaseous medium supplied under appropriate pressure from conventional sources is applicable. The casing of the preventer can be molded or assembled, for example, from a sleeve I of a casing string, with standard external diameter D 1, length H 2 and internal tapered threads. It is pivotally mounted on the conductor (Fig. 6 and 7). In the walls of the coupling, two through channels 2, 3 are designed for the passage of the working medium and mounting recess 4. Two through radial holes 5, 6 for the locking dogs 7, 8. The front ends of the dogs facing the main axis are cut off on one side at an angle α 1, providing self-braking when a force is applied to the dog, perpendicular to its axis. On the opposite - the angle α 2, for example ^about 45 - Ratchet providing spin pawl radially from the main axis when subjected to the said perpendicular force, ie, when operating in a ratchet mode... Both dogs are movably sealed with the walls of the holes 5, 6 and hinges 9, 10 connected to a two-arm T-shaped lever 11, a hinge 12 mounted on the earring 13 of the coupling 1. The central bore D 2 of the coupling 1 is equipped with a seal 14. It has a rod 15 with an internal the thread 16 of the collet piston 17 - with an external D 3, a through D 4 and the outlines of its cavity R 1, R 2, α 3, α 4, seals 18, an annular ratchet 19, with a cross-section profile of which the profiles of the dogs 7, 8 are matched. In the thread 16 of the collet piston 17, the shank 20 of the collet piston 21 is planted. I from the portion bounded by the D 4 and D 3 to the outside, is delimited radii R1 and R2, which are connected by a straight line, between which and the piston axis concluded structurally acceptable variable angle α 3 - from 30 ^o to α 4 - ^to 45. With α 3 and a constant axial force created by the piston, the maximum compression force of the column with dies is achieved with a significant piston stroke. Under α 4 and a constant axial force developed by the piston, a smaller compression force of the column with dies is achieved with a smaller piston stroke, which as a result positively affects the height of the preventer and the rational flow rate of the working medium. Manufactured pistons with ratchets are carried out only by turning - the cheapest.

 Two identical cylinders 22, 23 are joined with the tapered threads of the coupling 1, with flanges forming a body, the length of which is H 3. Each cylinder is equipped with a set of “pipe” dies 24, 25 or pipe and blind, fitted with splines on the axis, which are gear shafts 26, 27, 28 with blind 29, 30, 31 - axial, designed to supply the flushing medium with channels and radial 32, 33, 34, which are nozzles for supplying the medium to the crankcases 35, 36 in order to remove sludge from the collet pistons 17, 21 , cylinders 22, 23, dies 24, 25 and drill string 37 with an outer diameter D 7, improve the quality of sealing and increase the durability of the dies. The assembled preventer has two working cavities 38, 39 of its hydraulic motor.

 The dies are mounted on their gear shafts, brought to the "preventer is closed" position (Fig. 1) to the right of the axis, the bottom and all three are simultaneously processed by a turning method according to R 3 and the elements adjacent to the column.

 Due to the fact that the dies have a splined fit on their axes, i.e., on the gear shafts 26, 27, 28, interlocked with each other (Fig. 2) by rotating one of them (for example 26), rotation is reported clockwise and counterclockwise at a certain angle of rotation α 5 and synchronously transmitted to other shaft gears 27, 28 and dies. This is necessary for the simultaneous supply of dies to the column and removal from it. With a sharp rotation of the gear shafts with dies, an impact of their rear part, outlined by a radius R 3 on the crankcase wall, is achieved, due to which the amorphous and sticky sludge falls off and is washed off by jets of the washing medium escaping from the radial nozzles 32, 33, 34, making the same oscillatory movements , like dies, washing a much larger area of the crankcase than this can be achieved by jets ejected from fixed nozzles.

 For the described rotation of the dies of the lower and upper rows, a shank 40 is provided on one of the gear shafts of each row (Fig. 1, 2), where, for example, a lever (not shown) can be fitted to perform this operation.

 Work preventer-lineup I (Fig. 1). Sealing and depressurization of the well.

 The flow of the working medium through the channel 2 into the cavity 38, the piston blocks (17-21) (previously located in the middle position of Fig. 1, the left side, when the dies are open to D 4) will begin to move downward by ≈ H 4 and with their shoulder , outlined by R 2, squeeze the dies from the walls of the cylinder 22 and with their collet bore (from R 1 to R 2) will lead them from the neutral position (left side) to the position (bottom right side), i.e. close them. Moreover, when the piston blocks (17-21) move with a constant speed, the rams at the beginning of the movement with insignificant resistance will approach the column at a higher speed than before contact with it. This is achieved by the presence of radius R 1, which is part of the curve forming the bores of the collet pistons, which is used to ensure maximum compression of the dies to the column, at the same pressure of the working medium on the piston.

 Arbitrary movement of the piston blocks (17-21) in the opposite direction and depressurization of the well are excluded by the interaction of a dog 8 with an annular ratchet 19, angle α 1, providing self-braking. In addition, the lever 11 can be equipped with an additional stopper, for example, on the control panel.

 By supplying the working medium through the channel 3 to the cavity 39, the piston blocks (17-21) move upward by ≈ Н 4, as a result of which the lower dies 24 open, moving away from the column by a value a, and the upper dies 25 are closed. Moreover, the arbitrary movement of the piston blocks (17-21), and therefore the depressurization of the well, are excluded by the interaction of the dog 7 with the ratchet 19.

 Work preventer-lineup I (Fig. 1). Lock

 When the columns are paced, consisting of turning and axial movement, in the presence of pressure under the preventer above atmospheric, it is not uncommon for axial movement to stop as a result of stopping the coupling in the sealant. This is possible as a result of a mistake made in the layout of the column, or changed goals and working conditions. In such cases, the upper part of the column rises above the preventer, is assembled with pipes of specified length, is lowered into the well, after which its pacing continues. During the lifting and lowering of the column with a closed sealant, intensive wear occurs with pipes with an untreated surface. This phenomenon is considered normal. In addition, precious time is wasted. The proposed preventer completely eliminates these drawbacks by the fact that, for example, when lowering the column under similar conditions, it is sealed with an upper sealant. When the coupling approaches the upper sealant, it instantly opens, and the lower closes. When the coupling approaches the lower seal, it opens, and the upper instantly closes, after which the pacing of the column continues.

 This eliminates the need for accurate pipe selection in the layout of the column.

 Layout option II (Fig. 3) is a die-cuff with a cuff spline, which contains as a sealing element one set of dies 25 at the top of the preventer, completely repeating layout I (Fig. 1).

 The lower set of dies is replaced by a lip seal, which is a distant analog of a. with. USSR N 1.592.472 and application N 4.702.492 recognized by the invention.

 To obtain such a preventer, which is technologically necessary for drilling and researching wells that differ in particularly difficult technical characteristics of rocks and fluid, a lower cylinder 22 with dies 24 and a collet piston 21 are separated from the preventer (Fig. 1). Instead, a piston 41 with a wedge 42 and a sleeve 43 with a cuff 44 and a bracelet 45. Moreover, the wedge 42 is given the shape of a cylinder. The cuff retains its traditional design - a truncated hollow cone. A sealing device comprising 41 to 45 is the bottom of the preventer.

 The closure of the coupling joints of the drill string using the layout preventer II (Fig. 3) is carried out in the same way as this operation is performed using the layout preventer I (Fig. 1). Layout II is applicable with the cuff in the down position. The preventer joins the lower wellhead well piping with the end where the lip seal is located.

 Layout option III (Fig. 4), the ram-cuff, with a spline and cuff preload, contains as a sealing element one set of dies 25 in the upper part of the preventer, repeating layout I completely (Fig. 1).

 The lower set of dies is replaced by a modified lip seal, which is analogous to a. with. USSR N 1.592.472 and application N 4.702.492 recognized by the invention. It is applicable for conditions when, as a result of exposure to high or low temperatures on the cuff, it loses its physical properties of self-clamping to the column, when the cuff has already undergone significant wear and even forms a gap with the column at nominal temperature.

 Designed for additional forced firing of an overheated or supercooled cuff around the column, in the presence of extreme wear of the cuff and column and the annular gap between them. To obtain such a preventer, the lower cylinder 22 with dies 24 and the collet piston 21 are separated from the preventer (Fig. 1). Instead, a piston 41 with a cylindrical spline 42 and a sleeve 43 with a modified collar 46 is placed. The cuff retains the traditional conical shape of a truncated hollow cone. It can be made not only of rubber, but also of highly heat-resistant plastics. In the base part of the cuff, for example, three holes are formed with their own labyrinth seals, through which tightly sliding rods 47 pass, with their upper ends attached to the piston 41, and on the lower ends a blindly set snap ring 48 with a conical bore.

 When the piston 41 moves upward, the spline 42 exits the cuff, and the ring 48 covers its end and squeezes around the column, sealing the wellhead. When the piston moves down, the ring 48 automatically leaves the cuff, and the wedge 42 automatically increases the passage in it, ensuring the passage of the column contactless with the cuff. The supporting part of the preventer is its cuff section.

 Embodiment IV (FIG. 5) with dies and a lentil ring seal may comprise, for example, one set of dies 25 at the top of the preventer, repeating arrangement I (FIG. 1). And the bottom - lentil ring cuff 49, planted in a sleeve 50. In another case, the preventer can be equipped with two sealants (Fig. 4). The operating conditions of lentil ring cuffs 49 do not differ from the conditions of their operation in domestic and foreign preventers.

 The main disadvantages of the cuff 49 are: the exclusion of the possibility of working at high and low temperatures, residual deformation, destruction by confusion from high specific pressure on it. The supporting part of the preventer is any of its end.

Claims (4)

 1. A universal preventer comprising a hollow body with rotary around axes perpendicular to the axis of the well, and removed from it by an amount smaller than the radius of the cavity of the body, sealing elements, a collet piston and a locking mechanism, characterized in that, in order to increase reliability sealing and expanding the range of use of the preventer, including the automatic centering of its axis with the axis of the well and the locking of the coupling joints of the pipe string, it is equipped with additional sealing elements, installed in the body cavity, a double collet piston with a hollow rod, the inner surface of which interacting with the sealing elements is outlined by a curved line, the tangents to which form angles of variable size with the axis of the preventer, and additional sealing elements are installed with the possibility of interaction with the collet surfaces of the double pistons, the locking mechanism is made in the form of an earring with dogs and a two-shouldered lever mounted on it, installed with the possibility of interaction ystviya the housing and pawls, wherein the double piston has on the outer surface of the annular groove for the locking pawl mechanism.  2. The preventer according to claim 1, characterized in that the additional sealing elements are made in the form of a cuff having the shape of a hollow truncated cone with an axially movable ring with a conical bore made in the shape of the outer surface of the cuff.  3. The preventer according to claim 1, characterized in that it is equipped with an additional stopper located at the end of the body for fixing the latter relative to the wellhead harness, and additional sealing elements together with the body are rotatable around the axes, while the axis of rotation is perpendicular to the axis of the well, and the distance from the axis of rotation to the axis of the well exceeds the radius of the body.  4. The preventer according to claim 1, characterized in that the axes of the additional sealing elements are made rotary and with radial and axial channels for supplying a flushing agent.

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