Simulation experiment device for confining pressure test of oil and gas well

Abstract

The utility model relates to the technical field of oil and gas confining pressure experiments, in particular to a confining pressure simulation experiment device for oil and gas well testing. The oil and gas well test confining pressure simulation experiment device comprises a steel cylinder, mounting holes are formed in a cylinder body of the steel cylinder, a mounting pipe is fixedly mounted in each mounting hole, and a fluid valve group is arranged in each mounting pipe. According to the confining pressure simulation experiment device for the oil and gas well test, the steel cylinder is assembled with the mounting pipe, independent and controllable fluid jet points are formed, the built-in fluid valve group can be subjected to self-locking sealing design or manual adjustment opening and closing, radial non-uniform confining pressure simulation can be achieved, real stress distribution of a stratum is restored, and the confining pressure simulation effect is improved. The fluid valve group can be independently opened and closed, so that the injection points can be dynamically adjusted in the experiment process, the injection points in different directions can be opened and closed in stages, and meanwhile, the stress concentration phenomenon of a near wellbore zone in the drilling process is reduced by gradually increasing the radial injection points.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas confining pressure experiments, in particular to a simulation experiment device for the confining pressure of oil and gas well tests. Background Art

[0002] The confining pressure experiment in oil and gas well tests is a core type of rock mechanics experiment, mainly used to simulate the confining pressure (also known as hydrostatic pressure or lateral confinement pressure) that formation rocks bear underground under laboratory conditions, so as to measure the mechanical properties of rocks in this more realistic environment.

[0003] In the prior art, hydrostatic pressure simulation is mostly achieved through a sealed cavity, which has significant limitations. For example, the distribution of the injection points of the existing wellbores for experiments is single, and it can only simulate uniform confining pressure, unable to restore the radial non-uniform stress field in the real formation (such as the anisotropy in the fracture development area), and it is difficult to dynamically adjust the injection points, and it is impossible to flexibly increase or decrease or switch the pressure application points during the experiment.

[0004] Therefore, it is necessary to provide a new simulation experiment device for the confining pressure of oil and gas well tests to solve the above technical problems. Content of the Utility Model

[0005] To solve the above technical problems, the utility model provides a simulation experiment device for the confining pressure of oil and gas well tests.

[0006] The simulation experiment device for the confining pressure of oil and gas well tests provided by the utility model includes a steel cylinder, the top of the steel cylinder is provided with a threaded opening, and an end cover connected by threads is installed on the top of the steel cylinder;

[0007] A plurality of annularly distributed and radially arranged mounting holes are formed in the barrel body of the steel cylinder, a mounting pipe is fixedly installed in each mounting hole, and a fluid valve group is arranged in the mounting pipe, and a fluid liquid guide pipe is externally connected through the mounting pipe;

[0008] An integrally formed arc seat is arranged in the mounting pipe, a through cavity is arranged on the end face of the arc seat, and an arc-shaped expansion cavity is arranged at one end of the arc seat close to the steel cylinder;

[0009] The fluid valve group includes a fixed disk, a sliding rod connected in a sliding manner is inserted on the fixed disk, one end of the sliding rod extends out of the mounting pipe, and the other end of the sliding rod extends into the arc-shaped expansion cavity and is fixedly welded with a steel ball, and a spring is sleeved on the sliding rod, and the spring is used to drive the steel ball to block the through cavity to seal the mounting pipe.

[0010] Preferably, a reset cavity and a locking cavity coaxial with the arc-shaped expansion cavity are further formed in the installation pipe. The reset cavity is located between the arc-shaped expansion cavity and the locking cavity, and an internal thread section is arranged on the inner wall of a section of the locking cavity close to the reset cavity.

[0011] Preferably, a threaded column is fixedly sleeved on the sliding rod, and the threaded column is located in the locking cavity.

[0012] Preferably, a plurality of annularly distributed liquid flow cavities are formed in both the fixed disk and the threaded column.

[0013] Preferably, one end of the spring is fixedly connected to the cavity wall of the reset cavity close to the arc-shaped expansion cavity, and the other end of the spring abuts against the fixed disk.

[0014] Preferably, a knob is fixedly installed at one end of the sliding rod extending out of the installation pipe.

[0015] Preferably, a threaded quick connector is fixedly installed on the installation pipe.

[0016] Preferably, a threaded pressing column is fixedly installed at the bottom of the end cover. A conduit for communicating with the steel cylinder is fixedly installed on the end cover, and a valve is installed on the conduit.

[0017] Compared with the related art, the oil and gas well test confining pressure simulation experiment device provided by the present utility model has the following beneficial effects:

[0018] In the present utility model, a plurality of installation holes are annularly formed in the body of the steel cylinder, and installation pipes are assembled in each hole to form independent and controllable fluid injection points. The built-in fluid valve group can be designed for self-locking seal or manually adjusted for opening and closing. Therefore, radial non-uniform confining pressure simulation can be realized to restore the true stress distribution of the formation. Since the fluid valve group can be independently opened and closed, the injection points can be dynamically adjusted during the experiment (such as single-point or multi-point combined pressurization), and different azimuth injection points can be opened and closed in stages. At the same time, by gradually increasing the radial injection points, the stress concentration phenomenon in the near-wellbore area during the drilling process can be restored. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a preferred embodiment of the oil and gas well test confining pressure simulation experiment device provided by the present utility model;

[0020] Figure 2 is Figure 1 the structural diagram of the shown installation pipe;

[0021] Figure 3 is Figure 1 the internal structural diagram when the shown installation pipe is sectioned;

[0022] Figure 4 isFigure 1 Schematic cross-sectional structure diagram of the installation pipe shown

[0023] Figure 5 For Figure 3 Schematic structure diagram of the fluid valve group shown

[0024] Reference numerals in the figure: 1, steel cylinder; 1a, installation hole; 2, end cover; 21, conduit; 22, valve; 23, threaded pressing column; 3, installation pipe; 31, arc seat; 31a, through cavity; 32, internal thread section; 33, threaded quick connector; 3a, arc-shaped expanded cavity; 3b, reset cavity; 3c, locking cavity; 4, fluid valve group; 41, fixed disk; 42, sliding rod; 43, steel ball; 44, spring; 45, threaded column; 46, knob; 4a, liquid flow cavity Specific implementation mode

[0025] In order to make the purpose, technical solution and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model

[0026] The following describes in detail the specific implementation of the present utility model in combination with specific embodiments

[0027] Please refer to Figures 1 to 5 , an oil and gas well test confining pressure simulation experiment device provided by an embodiment of the present utility model, the oil and gas well test confining pressure simulation experiment device includes a steel cylinder 1, an installation pipe 3 and a fluid valve group 4

[0028] In an embodiment of the present utility model, please refer to Figures 1 to 5 , a plurality of annularly distributed and radially arranged installation holes 1a are provided on the barrel wall of the steel cylinder 1, and an installation pipe 3 is fixedly installed in each installation hole 1a. An integrally formed arc seat 31 is arranged in the installation pipe 3, and a through cavity 31a is provided on the end face of the arc seat 31. An arc-shaped expanded cavity 3a is arranged at one end of the arc seat 31 close to the steel cylinder 1, and a reset cavity 3b and a locking cavity 3c coaxially arranged with the arc-shaped expanded cavity 3a are further provided in the installation pipe 3. The reset cavity 3b is located between the arc-shaped expanded cavity 3a and the locking cavity 3c, and an internal thread section 32 is arranged on the inner wall of a section of the locking cavity 3c close to the reset cavity 3b

[0029] A fluid valve group 4 is arranged inside the installation pipe 3. The fluid valve group 4 includes a fixed disk 41. A sliding rod 42 connected in a sliding manner is inserted on the fixed disk 41. One end of the sliding rod 42 extends out of the installation pipe 3. A knob 46 is fixedly installed at the end of the sliding rod 42 extending out of the installation pipe 3. The other end of the sliding rod 42 extends into the arc-shaped expansion cavity 3a and is fixedly welded with a steel ball 43. A spring 44 is sleeved on the sliding rod 42. One end of the spring 44 is fixedly connected with the cavity wall of the reset cavity 3b close to the arc-shaped expansion cavity 3a, and the other end of the spring 44 abuts against the fixed disk 41. The steel ball 43 is driven by the spring 44 to block the through cavity 31a to realize the sealing of the installation pipe 3. A threaded column 45 is fixedly sleeved on the sliding rod 42, and the threaded column 45 is located in the locking cavity 3c. A number of annularly distributed liquid flow cavities 4a are opened on both the fixed disk 41 and the threaded column 45.

[0030] In this application, a plurality of annularly distributed installation pipes 3 are installed on the steel cylinder 1. When each installation pipe 3 is externally connected to a fluid guiding pipe, the installation pipe 3 at the installation hole 1a at this place constitutes a fluid injection point. The opening and closing of the fluid injection point of the installation pipe 3 are realized through the fluid valve group 4. Specifically:

[0031] When the installation pipe 3 is not externally connected to a fluid guiding pipe, under the elastic force of the spring 44, the steel ball 43 is driven to block the through cavity 31a to realize the sealing of the installation pipe 3. Therefore, the installation pipe 3 at this position on the steel cylinder 1 does not constitute a fluid injection point. Among them, when the fluid sprayed into the steel cylinder 1 from other injection points in the steel cylinder 1 flows to the installation pipe 3 at the installation hole 1a of this application, since the fluid flowing into the arc-shaped expansion cavity 3a only generates a driving force on the steel ball 43 in the direction of the locking cavity 3c, the sealing effect of the steel ball 43 on the through cavity 31a is further enhanced, so that the installation pipe 3 will not leak fluid;

[0032] When the installation pipe 3 needs to be externally connected to a fluid guiding pipe to form a fluid injection point, before connecting the fluid guiding pipe, the inner pressure knob 46 drives the sliding rod 42 to slide towards the inside of the installation pipe 3 until the threaded column 45 abuts against the internal thread section 32. Then, the knob 46 is rotated to drive the threaded column 45 to screw into the internal thread section 32. At this time, the fixed disk 41 compresses the spring 44 and the steel ball 43 slides to the arc-shaped expansion cavity 3a, so that the steel ball 43 no longer seals the through cavity 31a, and thus the installation pipe 3 constitutes a fluid injection point. Then, the fluid guiding pipe is docked with the installation pipe 3.

[0033] It should be noted that: This application sets a plurality of fluid injection points on the barrel body of the steel cylinder 1 that can be opened and closed at any time. Therefore, when testing the strength of rocks under the simulated formation confining pressure conditions, the confining pressure experiment on the rocks can be carried out by gradually adding fluid injection points and setting fluid injection points in different orientations to start.

[0034] Among them, a threaded quick connector 33 is fixedly installed on the installation pipe 3, which is convenient for externally connecting a fluid guiding pipe.

[0035] In this application, a plurality of mounting holes 1a are annularly formed in the barrel body of the steel barrel 1, and mounting pipes 3 are assembled in each hole to form independently controllable fluid injection points. The built-in fluid valve group 4 can be designed for self-locking seal or manually adjusted for opening and closing. Therefore, radial non-uniform confining pressure simulation can be realized to restore the true stress distribution of the formation. Since the fluid valve group 4 can be independently opened and closed, the injection points can be dynamically adjusted during the experiment (such as single-point or multi-point combined pressurization), and the injection points in different directions can be opened and closed in stages. At the same time, by gradually increasing the radial injection points, the stress concentration phenomenon in the near-wellbore zone during the drilling process can be restored.

[0036] In the embodiment of the present utility model, please refer to Figures 1 to 5 , the top of the steel barrel 1 is provided with a threaded opening, and an end cap 2 connected by threads is installed at the top of the steel barrel 1. A threaded pressing column 23 is fixedly installed at the bottom of the end cap 2. A conduit 21 for communicating with the steel barrel 1 is fixedly installed on the end cap 2, and a valve 22 is installed on the conduit 21.

[0037] It should be noted that: after the rock for the experiment is placed into the steel barrel 1, the threaded pressing column 23 is inserted into the steel barrel 1 to be threadedly connected with the threaded opening, and the threaded pressing column 23 is axially pressed against the rock by screwing in to improve the stability of the rock during the experiment.

[0038] It should also be noted that: an axial pressing detection experiment on the rock can also be carried out by connecting a fluid guide pipe to the conduit 21 and opening the valve 22.

[0039] The circuits and controls involved in the present utility model are all prior arts and will not be elaborated here.

[0040] The above are only the embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present utility model.

Claims

1. An experimental device for simulating confining pressure in oil and gas well testing, comprising a steel cylinder (1). The top of the steel cylinder (1) is provided with a threaded opening, and an end cover (2) connected by threads is installed at the top of the steel cylinder (1). It is characterized in that: A number of annularly distributed and radially arranged mounting holes (1a) are formed in the barrel body of the steel cylinder (1). A mounting pipe (3) is fixedly installed in each mounting hole (1a), and a fluid valve group (4) is arranged in the mounting pipe (3). A fluid guide pipe is externally connected through the mounting pipe (3). An integrally formed arc seat (31) is arranged in the mounting pipe (3). A through cavity (31a) is provided on the end face of the arc seat (31), and an arc-shaped enlarged cavity (3a) is arranged at one end of the arc seat (31) close to the steel cylinder (1). The fluid valve group (4) includes a fixed disk (41). A sliding rod (42) connected in a sliding manner is inserted on the fixed disk (41). One end of the sliding rod (42) extends out of the mounting pipe (3), and the other end of the sliding rod (42) extends into the arc-shaped enlarged cavity (3a) and is fixedly welded with a steel ball (43). A spring (44) is sleeved on the sliding rod (42). The spring (44) drives the steel ball (43) to block the through cavity (31a) to seal the mounting pipe (3).

2. The simulated experimental device for confining pressure of oil and gas well testing according to claim 1, wherein A reset cavity (3b) and a locking cavity (3c) coaxial with the arc-shaped enlarged cavity (3a) are further formed in the mounting pipe (3). The reset cavity (3b) is located between the arc-shaped enlarged cavity (3a) and the locking cavity (3c). An internal thread section (32) is arranged on the inner wall of a section of the locking cavity (3c) close to the reset cavity (3b).

3. The oil and gas well testing confining pressure simulation experimental device according to claim 2, characterized in that A threaded column (45) is fixedly sleeved on the sliding rod (42), and the threaded column (45) is located in the locking cavity (3c).

4. The simulated experiment device for confining pressure of oil and gas well testing according to claim 3, wherein, A number of annularly distributed liquid flow cavities (4a) are formed on both the fixed disk (41) and the threaded column (45).

5. The simulated experiment device for confining pressure of oil and gas well testing according to claim 2, wherein One end of the spring (44) is fixedly connected to the cavity wall of the reset cavity (3b) close to the arc-shaped enlarged cavity (3a), and the other end of the spring (44) abuts against the fixed disk (41).

6. The simulated experiment device for confining pressure in oil and gas well testing according to claim 1, characterized in that, A knob (46) is fixedly installed at one end of the sliding rod (42) extending out of the mounting pipe (3).

7. The simulated experiment device for confining pressure of oil and gas well testing according to claim 1, characterized in that A threaded quick connector (33) is fixedly installed on the mounting pipe (3).

8. The simulated experiment device for confining pressure in oil and gas well testing according to claim 1, wherein A threaded pressing column (23) is fixedly installed at the bottom of the end cover (2). A conduit (21) for communicating with the steel cylinder (1) is fixedly installed on the end cover (2), and a valve (22) is installed on the conduit (21).

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