Device and method for measuring pressure in pipe column water hole after cock is closed during blowout

Abstract

The invention discloses a device and a method for measuring pressure in a pipe column water hole after a cock is closed during blowout. The device comprises a measuring clamp which is clamped on the cock during working; the measuring clamp is provided with a measuring hydraulic device which is connected with an oil pump. The measuring hydraulic device comprises a hydraulic cylinder barrel and a piston rod arranged in the hydraulic cylinder barrel, the two ends of the piston rod extend out, a piston is arranged on the piston rod, and the cross sectional area of the piston is equal to the area of the lower surface of a rotary knob of the cock; the end, extending out of the hydraulic cylinder barrel, of the piston rod is connected with a rotary knob of the cock in a matched mode during working. And a pressure gauge is arranged between the oil pump and the measuring hydraulic device. Operation is safe and reliable, and the principle is simple and feasible. According to the utility model, the cock does not need to be opened, the pressure in the tubular column (i.e., the vertical pressure of the shut-in well) can be accurately measured under the well shut-in safety state, and the problem that the vertical pressure cannot be accurately obtained after the cock shuts in the well is solved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, and relates to a device and method for measuring the pressure inside the water hole of the tubing after the plug is closed during a blowout. Background Technology

[0002] As oil and gas fields are developed at deeper depths, formation pressure increases, and the pressure on well control equipment also increases. During drilling and workover, if the formation pressure exceeds the annular fluid column pressure, the formation pressure will push the fluid in the annulus upwards along the drill string. At the same time, formation fluid will also infiltrate the fluid inside the drill string and slide along it, resulting in a well kick or blowout.

[0003] After a well kick or blowout, it is necessary to quickly shut off the wellhead blowout preventer assembly (to control the annulus) and the stopcock installed on the drill string (to control the water passage). The stopcock is closed by using a special tool to rotate the knob, which rotates the ball valve to close the water passage. After shut-in, the annulus pressure (casing pressure) can be read through the choke manifold pressure gauge, but the water passage pressure (standby pressure) cannot be read due to the closure of the blowout preventer (stopcock) at the wellhead, affecting subsequent accident handling procedures. Simultaneously, during accident handling, it is necessary to open the stopcock to establish a circulation channel. However, in the shut-in state, the ball valve of the stopcock is difficult to open due to the immense unidirectional pressure (up to 50 MPa or more). When the standby pressure in the drill string is high, the stopcock is difficult to open, often causing damage to the stopcock and the upper manifold. The ease of opening the stopcock is directly related to the standby pressure in the drill string. It is necessary to know the magnitude of the standby pressure and apply a corresponding balancing pressure (to balance the standby pressure in the well) in the opposite direction from the stopcock to ensure successful opening. Therefore, it is essential to accurately measure the stand-up pressure inside the tubing nozzle when the stopcock is closed. However, there are currently no effective monitoring tools or methods for monitoring the stand-up pressure inside the tubing after the stopcock is closed during oil drilling and workover operations. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that there are no effective monitoring tools and methods for monitoring the standing pressure in the tubing after the plug is closed during oil drilling and well workover operations, and to provide a device and method for measuring the pressure in the water hole of the tubing after the plug is closed during a blowout.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides a measuring device for measuring the pressure inside the tubing after the plug is closed during a blowout, comprising a measuring clamp held on the plug during operation; a measuring hydraulic device is provided on the measuring clamp, and the measuring hydraulic device is connected to an oil pump; the measuring hydraulic device includes a hydraulic cylinder and piston rods disposed therein with both ends extending out, a piston is provided on the piston rods, and the cross-sectional area of ​​the piston is equal to the lower surface area of ​​the plug knob; the end of the piston rod extending out of the hydraulic cylinder is engaged with the plug knob during operation; a pressure gauge is provided between the oil pump and the measuring hydraulic device.

[0007] A further improvement of the present invention is as follows:

[0008] The measuring fixture is a circular fixture composed of two semicircular rings connected together; the two semicircular rings are connected by a connector; the measuring hydraulic device is installed through one of the semicircular rings, and the axis of the piston rod is perpendicular to the axis of the semicircular ring.

[0009] The two semicircular rings are provided with connecting protrusions at their joint positions, and threaded holes are provided on the connecting protrusions. The connecting component is a bolt, which passes through the threaded holes to fix the two semicircular rings together and fix them on the stopcock.

[0010] When the hydraulic cylinder is in operation, the end away from the knob is provided with an oil return nozzle and an oil inlet nozzle connected to the oil pump.

[0011] The measuring hydraulic device is connected to the oil pump via an oil pipeline; the length of the oil pipeline is greater than the set safe distance between the operator and the wellhead.

[0012] The oil pipeline includes an oil inlet pipeline connected to the oil inlet nozzle and an oil return pipeline connected to the oil return nozzle; a control valve and a safety valve are installed on the oil inlet pipeline; and a pressure gauge is installed on the oil inlet pipeline.

[0013] The oil pump is either an electric hydraulic pump or a manual hydraulic pump.

[0014] The hydraulic cylinder and the piston rod are sealed with a metal seal.

[0015] The portion of the piston rod extending out of the hydraulic cylinder is a prismatic structure that matches the groove shape on the knob used for switching the valve.

[0016] Secondly, the present invention provides a method for measuring the pressure inside the tubing after the plug is closed during a well blowout, comprising the following steps:

[0017] Step 1: Install the measuring fixture at the position of the knob on the stopcock, so that the piston rod in the measuring hydraulic device is connected to the knob, and then tighten the two semi-circular rings of the measuring fixture with bolts.

[0018] Step 2: Turn on the oil pump and slowly increase the pressure. Observe the pressure gauge reading. When the pressure gauge reading rises sharply, the pressure value at the inflection point is the pressure value inside the water hole of the tubing after the stopcock is closed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses a device for measuring the pressure inside the tubing after the stopcock is closed during a blowout. One end of the piston rod in the hydraulic measuring device is connected to the knob of the stopcock. The sealing device between the knob and the ball valve has an elastic seal, which has the characteristic of generating a certain displacement under pressure. The oil pump applies pressure, pushing the piston towards the knob. The knob of the stopcock tends to displace inwards. The hydraulic pressure inside the tubing hinders the inward movement of the knob. When the oil pump pressure is less than the pressure inside the tubing, the pressure slowly rises with the pressurization of the hydraulic cylinder. When the oil pump pressure and the pressure inside the tubing are balanced, the pressure inside the hydraulic cylinder is stable, and the stopcock knob begins to slowly move inwards (this stroke is very short, 3-5 mm). When the oil pump pressure is greater than the pressure inside the tubing, and the knob moves inwards and contacts the ball valve, the pressure inside the hydraulic cylinder rises sharply. Therefore, the inflection point when the pressure inside the hydraulic cylinder rises sharply is the pressure inside the tubing. The pump is stopped, and this pressure is recorded to obtain the shut-in pressure at this time. This hydraulic measuring device is externally mounted to the shut-in cock, ensuring safe and reliable operation. Its principle is simple and feasible. Without opening the cock, it accurately measures the pressure inside the tubing (i.e., shut-in standpressure) while maintaining a safe shut-in state, solving the problem of inaccurate standpressure measurement after the cock has been shut in.

[0021] Furthermore, the measuring hydraulic device is connected to the oil pump via an oil pipeline; the length of the oil pipeline is greater than the set safe distance between the operator and the wellhead, which can ensure the safety of the operator. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a structural diagram of the measuring fixture in a device for measuring the pressure inside the tubing after the plug is closed during a blowout, according to the present invention.

[0024] Figure 2 This is a side view of the measuring hydraulic device in a measuring device for the pressure inside the tubing after the plug is closed during a blowout, according to the present invention.

[0025] Figure 3This is a partial cross-sectional view of the measuring hydraulic device in a measuring device for the pressure inside the tubing after the plug is closed during a blowout, according to the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of a device for measuring the pressure inside the tubing after the plug is closed during a blowout, according to the present invention.

[0027] Figure 5 This is a structural diagram of the plug in this invention.

[0028] Wherein: 1-Measuring fixture; 2-Connecting bolt; 3-Hydraulic cylinder gland; 4-Glander bolt; 5-Hydraulic cylinder barrel; 6-Piston rod; 7-Return nozzle; 8-Inlet nozzle; 9-Upper hexagonal rod; 10-Piston seal; 11-Glander seal; 12-Cylinder body seal; 13-Lower hexagonal rod; 14-Cock valve; 15-Measuring hydraulic device; 16-Control valve; 17-Pressure gauge; 18-Inlet line; 19-Oil pump; 20-Return line; 21-Safety valve; 22-Cock valve body; 23-Knob; 24-Ball valve. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0034] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings:

[0036] See Figure 1 and Figure 4This invention discloses a device for measuring the pressure inside the tubing eye after the plug is closed during a blowout. The device includes a measuring clamp 1 held on the plug 14 during operation. The measuring clamp 1 is a circular clamp composed of two semi-circular rings connected together. The plug 14 includes a plug body 22, in which a ball valve 24 is disposed. The ball valve 24 is connected to one end of a knob 23, and the other end of the knob 23 extends out of the wall of the plug body 22. Connecting protrusions are provided at the points where the two semi-circular rings are connected, and threaded holes are provided on the connecting protrusions. The connecting element is a bolt, which passes through the threaded holes to fix the two semi-circular rings together, thus fixing them to the plug 14. The measuring hydraulic device 15 is mounted through one of the semicircular rings, with the piston rod 6's axis perpendicular to the semicircular ring's axis. The measuring fixture 1 is equipped with the measuring hydraulic device 15, which is connected to an oil pump 19. The measuring hydraulic device 15 includes a hydraulic cylinder 5 and piston rods 6 extending from both ends within it. A piston is mounted on the piston rod 6, and the cross-sectional area of ​​the piston is equal to the lower surface area of ​​the knob of the stopcock 14. When working, the end of the piston rod 6 extending from the hydraulic cylinder 5 engages with the knob of the stopcock 14. A pressure gauge 17 is installed between the oil pump 19 and the measuring hydraulic device 15. The measuring hydraulic device 15 is connected to the oil pump 19 via an oil pipeline; the length of the oil pipeline is greater than the set safe distance between the operator and the wellhead. The oil pipeline includes an inlet pipeline 18 connected to the inlet nozzle 8 and a return pipeline 20 connected to the return nozzle 7; a control valve 16 and a safety valve 21 are installed on the inlet pipeline 18; a pressure gauge 17 is installed on the inlet pipeline 18. The oil pump 19 is an electric hydraulic pump or a manual hydraulic pump. Connect one end of the piston rod 6 in the hydraulic measuring device 15 to the knob of the stopcock. The oil pump 19 applies pressure, pushing the piston towards the knob. The knob will tend to move inwards, but the hydraulic pressure within the tubing hinders this inward movement. When the pressure in the oil pump 19 is less than the pressure within the tubing, the pressure slowly rises with the increase in pressure in the hydraulic cylinder. When the pressure in the oil pump 19 balances with the pressure within the tubing, the pressure in the hydraulic cylinder stabilizes, and the stopcock begins to move slowly inwards (this stroke is very short, 3-5 mm). When the pressure in the oil pump 19 exceeds the pressure within the tubing, and the stopcock contacts the ball valve, the pressure in the hydraulic cylinder 5 rises sharply. Therefore, the inflection point when the pressure in the hydraulic cylinder 5 rises sharply is the pressure within the tubing. Stop the pump and record this pressure to obtain the shut-in pressure at this point. This hydraulic measuring device is externally mounted to the stopcock after the well has been safely shut in; it is safe, reliable, and based on a simple and feasible principle. Without opening the plug, the pressure inside the tubing (i.e., shut-in stand-up pressure) can be accurately measured while maintaining a safe shut-in state, solving the problem of not being able to accurately obtain stand-up pressure after plug shut-in.

[0037] See Figure 2 and Figure 3The hydraulic cylinder 5, when in operation, has a return oil nozzle 7 and an inlet oil nozzle 8 connected to the oil pump 19 at the end away from the knob. The hydraulic cylinder 5 and the piston rod 6 are sealed with a metal seal. The portion of the piston rod 6 extending out of the hydraulic cylinder 5 is a prismatic structure that matches the groove shape of the switch valve 14 on the knob.

[0038] This invention also discloses a method for measuring the pressure inside the tubing after the plug is closed during a well blowout, comprising the following steps:

[0039] Step 1: Install the measuring fixture 1 at the position of the knob on the stopcock 14, so that the piston rod 6 in the measuring hydraulic device 15 is connected to the knob, and then tighten the two semi-circular rings of the measuring fixture 1 with bolts.

[0040] Step 2: Turn on oil pump 19 and slowly increase the pressure. Observe the reading of pressure gauge 17. When the reading of pressure gauge 17 rises sharply, the pressure value at the inflection point is the pressure value in the water eye of the tubing after the stopcock is closed.

[0041] The method is described below with reference to specific embodiments:

[0042] Implementation conditions: Select a plug valve with a nominal diameter of 5 1 / 2”, an outer diameter of 139.7 mm, a rated pressure of 105 MPa, and a shut-in pressure that is the difference between the formation pressure and the drilling fluid column pressure, and does not exceed the maximum shut-in pressure at the wellhead; the experimental medium is clean water, and the temperature is ambient temperature of 5-30℃.

[0043] S1. Prepare test fixture 1, measuring hydraulic device 15, oil pump 19 and pipeline instruments and other facilities according to the size of the cock and the rated pressure.

[0044] The wellhead blowout preventer is closed, and the drill string connection stopcock 14 is closed, allowing the drill string to withstand the pressure of the formation overflow fluid. The measuring clamp 1 holds the stopcock 14, and the upper hexagonal rod 9 of the piston rod 6 is matched and connected to the stopcock knob. Considering factors such as formation pressure and drilling fluid column pressure, the hydraulic pump 19 is planned to be an electric or manual hydraulic pump with a pressure of less than or equal to 60 MPa.

[0045] S2. Install the measuring fixture 1 at the knob position of the stopcock 14. The measuring hydraulic device 15 is embedded in the fixture. The hexagonal rod 9 on the piston rod matches the stopcock knob. Connect the bolt 2 and start tightening with a wrench.

[0046] Before installing the measuring fixture 1, the knob of the stopcock 14 must be aligned with the hexagonal 9 on the piston rod of the measuring hydraulic device 15, and the hexagonal 9 on the piston rod must be inserted into the knob of the stopcock 14 for hydraulic measurement. When installing the two-part fixture, first install half on the side without the measuring hydraulic device 15, then install the other half, quickly connect the bolts 2, and tighten them with a wrench.

[0047] S3. Connect pipelines, valves, pumps, and other facilities to ensure that the valves are in the open position.

[0048] After installing and tightening the measuring fixture 1, connect the oil nozzle 8, return oil nozzle 7, control valve 16, pressure gauge 17, high-pressure oil pipe 18, return oil pipe 20 and oil pump 19 together.

[0049] The high-pressure oil pipe 18 and the return oil pipe 20 are connected by quick-connect interfaces at both ends, and are longer than 10 meters. There is a separation between the hydraulic oil pump 19 and the measuring hydraulic device 15 at the test site to ensure operational safety.

[0050] S4. After confirming that the installation is correct, begin hydraulic measurement.

[0051] Open valve 16 to inject hydraulic oil into the hydraulic cylinder chamber via oil pump 19, simultaneously venting the air inside the cylinder. First, raise the oil pressure to 0.5 MPa and maintain it for 5 minutes, checking for leaks at all connections. If no leaks are found, slowly increase the pressure and record the readings. When the oil pressure decreases, it indicates that the valve knob has been opened. Continue to slowly increase the pressure. When the oil pressure rises sharply, record the pressure data at the inflection point; this pressure value is the internal pressure of the tubing. Stop increasing the pressure. After depressurizing, repeat the above steps three times, and calculate the average of the three readings as the internal pressure of the tubing. Based on the internal pressure of the tubing, set the torque value for opening the valve. The valve can then be opened with a special wrench for subsequent emergency handling measures.

[0052] The working principle of this invention is as follows:

[0053] The piston rod 6 of the measuring hydraulic device 15 is connected to the hexagonal inner valve knob. The movement of the piston rod 6 pushes the valve knob inward to establish a balance with the hydraulic pressure in the tubing. As the pressure inside hydraulic cylinder 5 increases, it pushes the stopcock knob inward (in the stopcock structure, the stopcock valve knob itself will have a certain displacement outward after the well is shut in and pressurized. When the hydraulic cylinder of the hydraulic measuring device pushes, the stopcock valve knob will have a certain displacement inward). The hydraulic pressure in the tubing hinders the stopcock knob from moving inward. When the pressure inside hydraulic cylinder 5 is less than the pressure inside the tubing, the pressure will slowly rise as the oil pump 19 pressurizes. When the pressure inside hydraulic cylinder 5 is balanced with the pressure inside the tubing, the pressure inside hydraulic cylinder 5 is in a stable state and begins to push the stopcock knob to move slowly inward (this stroke is very short, 3-5mm). When the pressure inside hydraulic cylinder 5 is greater than the pressure inside the tubing and the stopcock knob moves inward and contacts the ball valve, the pressure inside hydraulic cylinder 5 rises sharply. Therefore, the inflection point when the pressure inside hydraulic cylinder 5 rises sharply is the pressure inside the tubing. Stop the pump, record this pressure, and you can get the shut-in stand pressure at this time. When the pipeline pressure exceeds the set value, the pressure can be reduced by releasing pressure through safety valve 21. Therefore, the pressure inside the tubing can be measured by the pressure of the hydraulic cylinder.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for measuring the pressure inside the tubing after the plug is closed during a well blowout, characterized in that, The device includes a measuring fixture (1) that is clamped onto a stopcock (14) during operation; a measuring hydraulic device (15) is provided on the measuring fixture (1), and an oil pump (19) is connected to the measuring hydraulic device (15); the measuring hydraulic device (15) includes a hydraulic cylinder (5) and piston rods (6) that are disposed inside the cylinder and extend out at both ends, a piston is provided on the piston rods (6), and the cross-sectional area of ​​the piston is equal to the lower surface area of ​​the knob of the stopcock (14); when the piston rod (6) extends out of the hydraulic cylinder (5), it is connected to the knob of the stopcock (14) during operation; a pressure gauge (17) is provided between the oil pump (19) and the measuring hydraulic device (15).

2. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... The measuring fixture (1) is a circular fixture composed of two semi-circular rings connected together; the two semi-circular rings are connected by a connector; the measuring hydraulic device (15) is installed through one of the semi-circular rings, and the axis of the piston rod (6) is perpendicular to the axis of the semi-circular ring.

3. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 2, is characterized in that... The two semicircular rings are provided with connecting protrusions at the joint positions, and threaded holes are provided on the connecting protrusions; the connecting component is a bolt, which passes through the threaded holes to fix the two semicircular rings together and fix them on the stopcock (14).

4. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... When the hydraulic cylinder (5) is working, the end away from the knob is provided with an oil return nozzle (7) and an oil inlet nozzle (8) connected to the oil pump (19).

5. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... The measuring hydraulic device (15) is connected to the oil pump (19) via an oil pipeline; the length of the oil pipeline is greater than the set safe distance between the operator and the wellhead.

6. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 5, is characterized in that... The oil pipeline includes an oil inlet pipeline (18) connected to the oil inlet nozzle (8) and an oil return pipeline (20) connected to the oil return nozzle (7); a control valve (16) and a safety valve (21) are provided on the oil inlet pipeline (18); and a pressure gauge (17) is provided on the oil inlet pipeline (18).

7. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... The oil pump (19) is an electric hydraulic pump or a manual hydraulic pump.

8. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... The hydraulic cylinder (5) and the piston rod (6) are sealed with metal.

9. The device for measuring the pressure inside the tubing after the plug is closed during a blowout, as described in claim 1, is characterized in that... The portion of the piston rod (6) extending out of the hydraulic cylinder (5) is a prismatic structure that matches the groove shape of the knob for the switch plug (14).

10. A method for measuring the pressure inside the water hole of the tubing string after the plug is closed during a well blowout, characterized in that, Includes the following steps: Step 1: Install the measuring fixture (1) at the position of the knob on the stopcock (14), so that the piston rod (6) in the measuring hydraulic device (15) is connected to the knob, and then tighten the two semi-circular rings of the measuring fixture (1) with bolts. Step 2: Turn on the oil pump (19), slowly increase the pressure, and observe the reading of the pressure gauge (17). When the reading of the pressure gauge (17) rises sharply, the pressure value at the inflection point is the pressure value inside the water hole of the tubing after the stopcock is closed.

Images