Well completion pipe string

Abstract

The utility model provides a well completion pipe column which comprises a lower supporting pipe column and an upper well completion pipe column, a packer is arranged at the top of the lower supporting pipe column, a plugging valve is arranged below the packer and arranged in the lower supporting pipe column, a flushing pipeline is arranged at the lower end of the upper well completion pipe column, and a water outlet pipe is arranged at the lower end of the flushing pipeline. The flushing pipeline is inserted into the lower supporting pipe column so that the lower supporting pipe column and the upper well completion pipe column can be connected into a whole, and a hydraulic packer is arranged above the flushing pipeline. The temporary plugging device can directly realize temporary plugging of a reservoir, so that well control safety is ensured, reservoir pollution is avoided, and meanwhile, well control risks are thoroughly avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas field drilling and completion, and particularly relates to an intrinsically safe completion string. Background Art

[0002] In carbonate fracture-vuggy oil and gas reservoirs, the probability of lost circulation during drilling is relatively high, and the lost circulation is likely to deteriorate into a blowout. The safety window is narrow, the oil and gas are active, and there is a lack of means to control the water eye, resulting in extremely high well control risks. For the "three highs" gas wells in ultra-deep condensate gas fields, the oil and gas are active, the completion operation process is complex and time-consuming, and well overflow, lost circulation, and even well collapse are likely to occur. Usually, continuous mud injection is used to maintain the liquid column pressure in the wellbore, thereby ensuring well control safety. However, this method is likely to cause reservoir pollution, and the well control risk cannot be completely eliminated. Summary of the Utility Model

[0003] An object of the utility model is to provide a completion string to directly achieve temporary plugging of the reservoir, thereby ensuring well control safety, avoiding causing reservoir pollution, and completely avoiding well control risks at the same time.

[0004] According to the utility model, there is provided a completion string, including: a lower support string and an upper completion string. A packer is arranged at the top of the lower support string, a plugging valve is arranged below the packer, the plugging valve is arranged inside the lower support string, a flushing pipeline is arranged at the lower end of the upper completion string, a hydraulic packer is arranged above the flushing pipeline, and the flushing pipeline is inserted into the lower support string so that the lower support string and the upper completion string are connected into one body.

[0005] In a preferred embodiment, the upper completion string is arranged above the lower support string.

[0006] In a preferred embodiment, the packer is a hanging packer.

[0007] In a preferred embodiment, the upper completion string further includes a landing nipple arranged above the hydraulic packer.

[0008] In a preferred embodiment, after setting, the packer can cut off the annulus channel, so that the open-hole wellbore is temporarily plugged.

[0009] In a preferred embodiment, the plugging valve is used to cut off the internal channel of the lower support string.

[0010] In a preferred embodiment, the plugging valve adopts a POP valve.

[0011] In a preferred embodiment, the lower support string is provided with a plurality of holes below the plugging valve.

[0012] In a preferred embodiment, a plurality of the holes are uniformly arranged along the extending direction of the lower support string.

[0013] In a preferred embodiment, the end of the lower support string is configured as an arc surface.

[0014] The utility model has at least the following technical effects:

[0015] According to the utility model, a lower support string and an upper completion string are provided. Since a packer is arranged at the top of the lower support string for isolating the annulus channel after setting, the open-hole wellbore is temporarily plugged. Also, since a blocking valve is arranged below the packer and the blocking valve is arranged inside the lower support string for isolating the internal channel of the lower support string, the fluid displacement channel in the well can be mechanically cut off by the packer and the blocking valve, so as to directly realize the temporary plugging of the reservoir, further ensure well control safety, avoid causing reservoir pollution, and completely avoid well control risks. Also, since a hydraulic packer is arranged above the flushing pipeline for protecting the integrity of the casing and the wellbore during the later production period after setting; and a flushing pipeline is arranged at the lower end of the upper completion string, and the flushing pipeline connects the lower support string and the upper completion string into one body, so that the blocking valve can be flushed through the flushing pipeline to ensure that the valve core of the blocking valve can be knocked down by applying pressure, realizing the smoothness of the oil and gas channel, and thus realizing essential safety completion and reducing mud loss. Description of the Drawings

[0016] Figure 1 Schematically shows a structural diagram of the lower support string of a completion string according to an embodiment of the utility model;

[0017] Figure 2 Schematically shows another structural diagram of the lower support string of a completion string according to an embodiment of the utility model, wherein the drill string is pulled out and disengaged from the lower support string;

[0018] Figure 3 Schematically shows a structural diagram of a completion string according to an embodiment of the utility model.

[0019] In this application, all the drawings are schematic drawings, only used to illustrate the principle of the utility model and not drawn according to the actual ratio. Detailed Embodiments

[0020] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In the present utility model, "a plurality of" means two or more.

[0022] In the present utility model, unless otherwise clearly defined and limited, the term "connection" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present utility model can be understood according to specific circumstances.

[0023] As Figures 1 to 3 shown, the completion string 100 of the present utility model includes: a lower support string a. A packer 1 is provided at the top of the lower support string a. The packer 1 is used to cut off the annulus channel after setting, so that the open-hole wellbore is temporarily plugged. A plugging valve 2 is provided below the packer 1. The plugging valve 2 is arranged inside the lower support string a and is used to cut off the internal channel of the lower support string a. An upper completion string b is provided above the lower support string a. A flushing pipeline 4 is provided at the lower end of the upper completion string b. The flushing pipeline 4 is communicated with the inside of the upper completion string b. The flushing pipeline 4 is inserted into the lower support string a to connect the lower support string a and the upper completion string b into one body. A hydraulic packer 3 is provided above the flushing pipeline 4. The hydraulic packer 3 is used to completely plug the open-hole wellbore after setting.

[0024] According to the present utility model, a lower support string a and an upper completion string b are provided. Since a packer 1 is provided at the top of the lower support string a for isolating the annulus channel after setting, the open-hole wellbore is temporarily plugged. Also, since a plugging valve 2 is provided below the packer 1 and the plugging valve 2 is arranged inside the lower support string a for isolating the internal channel of the lower support string a, the fluid displacement channel in the well can be mechanically cut off through the packer 1 and the plugging valve 2, directly realizing the temporary plugging of the reservoir, thereby ensuring well control safety, avoiding reservoir pollution, and completely avoiding well control risks. Also, since a hydraulic packer 3 is provided above the flushing pipe 4 for completely plugging the open-hole wellbore after setting to protect the integrity of the casing and the wellbore; and a flushing pipe 4 is provided at the lower end of the upper completion string a, and the flushing pipe 4 connects the lower support string b and the upper completion string a into one body, so that the plugging valve 2 can be flushed through the flushing pipe 4, so that the valve core of the plugging valve 2 can be damaged by pressure, realizing the smoothness of the oil and gas channel, and thus realizing essential safety completion and reducing mud loss.

[0025] In one or more embodiments, the packer 1 is a hanging packer.

[0026] In one or more embodiments, the plugging valve 2 is a temporary plugging valve and a POP valve can be used.

[0027] In one or more embodiments, the upper completion string a further includes a landing nipple (not shown in the figure) provided above the hydraulic packer 3.

[0028] In one or more embodiments, the lower support string b is provided with a plurality of holes below the plugging valve 2 for supporting the open hole and providing a channel for later oil and gas production at the same time.

[0029] In one or more embodiments, the plurality of holes are uniformly arranged along the extending direction of the lower support string b.

[0030] In one or more embodiments, the end of the lower support string b is configured as an arc surface.

[0031] The following briefly describes the use process of the completion string 100 according to the present utility model.

[0032] As Figures 1 to 3 shown, first, the lower support string b with the packer 1 and the plugging valve 2 is lowered in place through the drill string c; then the packer 1 is set, and after passing the inspection, the drill string c is released, displaced with mud, and pulled out of the well; the upper completion string a is lowered, and the flushing pipe 4 is inserted into the lower support string b to connect the lower support string b and the upper completion string a into one body, and the hydraulic packer 3 is set. Finally, pressure is applied in the tubing to knock down the valve core of the plugging valve 2, realizing the smoothness of the oil and gas channel and realizing essential well control safety throughout the process.

[0033] Although the present utility model has been described with reference to the preferred embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present utility model. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present utility model is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A completion string, characterized in that: include: A lower support tubular string and an upper completion tubular string, wherein a packer is arranged at the top of the lower support tubular string, a plugging valve is arranged below the packer, and the plugging valve is arranged inside the lower support tubular string, a flushing pipe is arranged at the lower end of the upper completion tubular string, a hydraulic packer is arranged above the flushing pipe, and the flushing pipe is inserted into the lower support tubular string, so that the lower support tubular string and the upper completion tubular string are connected as a whole.

2. The completion string according to claim 1, characterized in that: The upper completion string is arranged above the lower support string.

3. The completion string according to claim 1, characterized in that: The packer is a hanging packer.

4. The completion string according to claim 3, characterized in that: The upper completion string also includes a landing nipple disposed above the hydraulic packer.

5. The completion string according to claim 1, characterized in that: After being set, the packer can block the annular passage, so that the open hole wellbore is temporarily blocked.

6. The completion string according to claim 1, characterized in that: The blocking valve is used to block the internal passage of the lower supporting pipe column.

7. The completion string according to claim 1, characterized in that: The blocking valve is a POP valve.

8. The completion string according to claim 6, characterized in that: The lower supporting pipe column is provided with a plurality of holes below the blocking valve.

9. The completion string according to claim 8, characterized in that: The plurality of holes are evenly arranged along the extension direction of the lower supporting column.

10. The completion string according to claim 1, characterized in that: The end of the lower supporting column is configured as an arc-shaped surface.

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