Automatic grouting float shoe with sand filtering function

Abstract

The utility model discloses an automatic grouting float shoe with a sand filtering function, which comprises a positioning sealing joint connected with an upper outer layer sand prevention pipe column, and the positioning sealing joint is of a reducing structure; the lower end of the positioning sealing connector is connected with a screen pipe, a plurality of sand filtering hole channels are formed in the screen pipe, and a filter screen meeting the stratum sand prevention precision requirement is arranged in each sand filtering hole channel. A central pipe column is arranged in the upper outer layer sand prevention pipe column, the positioning sealing connector and the screen pipe, and a sealing packing is arranged between the positioning sealing connector and the central pipe column. When a sand prevention pipe column is tripped in, annular liquid automatically enters the drill rod, and meanwhile, due to the fact that a liquid flowing channel is a screen pipe hole, a good sand filtering effect is achieved; the whole float shoe adopts a small-size pipe column, when the upper-layer large-size sand prevention pipe column is blocked during drilling, a pump can be started for circulation, flushing is carried out while drilling is carried out, and the multiple purposes of automatic grouting, annular liquid filtering and flushing while drilling are achieved.

Description

Technical Field

[0001] The utility model belongs to the field of offshore sand prevention operations, in particular to an automatic grouting floating shoe with a sand filtering function. Background Art

[0002] At present, there are mainly two types of floating shoes at the bottom of sand control pipe strings used in open hole wells in offshore oil fields. One is a unidirectional floating shoe. During the period of delivering the sand control pipe strings to the place through drilling, each column needs to be filled with liquid. To ensure the quality of the filling, the pump is started and opened every 10-15 columns, which takes up drilling rig time and reduces operation efficiency. The other is a bidirectional floating shoe, which has an automatic grouting function during drilling, but has no filtering function. The liquid in the annulus directly flows back into the center pipe and drill pipe, which easily causes the annulus drill cuttings to enter the ball seat of the packer, causing the failure of the later set packer. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides an automatic grouting float shoe with a sand filtering function. The float shoe has the functions of sand filtering and automatic grouting, and can realize flushing and descending at the same time.

[0004] The utility model adopts the following technical solutions:

[0005] An automatic grouting float shoe with a sand filtering function comprises a positioning sealing joint connected to an upper outer layer sand control pipe column, the positioning sealing joint being a reduced diameter structure; the lower end of the positioning sealing joint is connected to a screen tube, a plurality of sand filtering channels are formed on the screen tube, and a filter screen that meets the requirements of formation sand control accuracy is arranged in each sand filtering channel; a central pipe column is arranged in the upper outer layer sand control pipe column, the positioning sealing joint and the screen tube, and a sealing packing is arranged between the positioning sealing joint and the central pipe column.

[0006] Furthermore, the lower end of the screen tube is connected to a blind plug.

[0007] Furthermore, the upper diameter of the central pipe column is larger than the middle and lower diameters.

[0008] Furthermore, a sealing portion is formed in the middle and lower part of the central pipe column, and the outer surface of the sealing portion is polished.

[0009] The beneficial effects of the utility model are:

[0010] 1. The positioning sealing joint is a reducer. After the reducer, the lower floating shoe is a small-size pipe column structure. When the upper outer layer of the sand control pipe column encounters resistance, the floating shoe structure can be used for circulating flushing while drilling;

[0011] 2. Sand filtering holes are evenly distributed on the bottom of the floating shoe. A filter that meets the requirements of formation sand control accuracy is placed in each hole. The specific sand control accuracy can be determined according to the actual situation of each well;

[0012] 3. The sand filter hole is a liquid flow channel that filters the annulus liquid. The liquid enters the center pipe through this hole and plays the role of automatic grouting and filtering during drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the utility model.

[0014] Among them, 1. Upper outer layer sand control pipe string; 2. Positioning sealing joint; 3. Positioning step; 4. Sealing packing; 5. Screen pipe; 6. Center pipe positioning step; 7. Center pipe string; 8. Blind plug. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0016] like Figure 1 As shown, an automatic grouting float shoe with sand filtering function includes a positioning sealing joint 2 connected to an upper outer layer sand control pipe column 1. The upper outer layer sand control pipe column 1 is an outer layer sand control pipe column required to be lowered into an oil well, including a screen pipe, a blind pipe, etc.; the positioning sealing joint 2 is connected to the upper outer layer sand control pipe column 1, and is connected to the screen pipe 5 and the blind plug 8 at the bottom, and plays a role in positioning and sealing the central pipe column 7. The positioning sealing joint 2 is a reduced diameter structure, the upper outer diameter is larger than the middle and lower outer diameters, and a positioning step 3 is formed at the reduced diameter position, and the positioning step 3 is used to position the central pipe column 7 and determine the central pipe column piping length.

[0017] The lower end of the positioning sealing joint 2 is connected to the screen tube 5, and a plurality of sand filter channels are formed on the screen tube 5. A filter screen that meets the requirements of formation sand control accuracy is placed in each channel. The sand filter channel is used to provide a flow channel for the annular space fluid to enter the central pipe column 7 during drilling, and the filter screen realizes automatic filtering of the fluid. The lower end of the screen tube 5 is connected to a blind plug 8, which is located at the bottom of the float shoe.

[0018] A central pipe column 7 is provided inside the upper outer layer sand control pipe column 1, the positioning sealing joint 2 and the screen pipe 5. The upper diameter of the central pipe column 7 is larger than the middle and lower diameters. A central pipe positioning step 6 is formed at the diameter change. The central pipe positioning step 6 is used for positioning when the central pipe is lowered. The required central pipe length is calculated according to the positioning length, thereby realizing the precise connection between the inner and outer layers of sand control pipe columns. A sealing part is formed in the middle and lower part of the central pipe column 7, and the outer surface of the sealing part is polished. A sealing packing 4 is provided between the sealing part and the positioning sealing joint 2, and the sealing part can realize effective sealing with the sealing packing. The sealing packing 4 is used to seal the inner layer central pipe and separate the upper and lower spaces of the central pipe column 7 and the outer layer of sand control pipe columns.

[0019] The working principle of the utility model is:

[0020] The positioning sealing joint 2 is a reducer, connected to the upper outer layer sand control pipe column 1, and connected to the floating shoe at the bottom. The floating shoe adopts a small-sized pipe column as a whole. When encountering resistance when drilling under the upper large-sized sand control pipe column, the pump can be turned on for circulation, flushing and lowering;

[0021] During the lowering of the sand control string, the annular liquid enters the float shoe from the sand filter hole to realize automatic grouting; a filter mesh that meets the requirements of formation sand control accuracy is placed in each sand filter hole, which can be set according to the actual formation conditions of each well to realize the filtering function of the liquid automatically injected into the central string.

[0022] The utility model effectively solves the problem that the liquid in the annulus directly flows back into the center pipe and the drill pipe in the current conventional floating shoes for sand control operations, which easily causes the annulus drill cuttings to enter the packer ball seat and cause the failure of the later set packer.

[0023] The drawings in the present invention are only used for illustrative purposes and represent only schematic diagrams rather than actual drawings, and should not be construed as limitations on this patent. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0024] Although the embodiments of the present invention have been shown and described above, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic grouting float shoe with sand filtering function, characterized in that: The invention comprises a positioning sealing joint (2) connected to an upper outer layer sand control pipe column (1), wherein the positioning sealing joint (2) is of a reduced diameter structure; the lower end of the positioning sealing joint (2) is connected to a screen tube (5), a plurality of sand filter channels are formed on the screen tube (5), and a filter screen that meets the requirements of formation sand control accuracy is arranged in each sand filter channel; a central pipe column (7) is arranged in the upper outer layer sand control pipe column (1), the positioning sealing joint (2) and the screen tube (5), and a sealing packing (4) is arranged between the positioning sealing joint (2) and the central pipe column (7).

2. The automatic grouting float shoe with sand filtering function according to claim 1 is characterized in that: The lower end of the screen tube (5) is connected to a blind plug (8).

3. The automatic grouting float shoe with sand filtering function according to claim 1 is characterized in that: The upper diameter of the central pipe column (7) is larger than the middle and lower diameters.

4. The automatic grouting float shoe with sand filtering function according to claim 1, characterized in that: The middle and lower part of the central pipe column (7) forms a sealing part, and the outer surface of the sealing part is polished.

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