A hydrogeological drilling single plug positive circulation dynamic water gravel filling water stopping technology

Abstract

The invention relates to the technical field of hydrogeological drilling and well formation, and discloses a hydrogeological drilling single plug positive circulation dynamic water filling gravel water stopping process, including: the well formation pipe is lowered into the borehole to form a filling space between the borehole and the well formation pipe; the well formation pipe includes a sedimentation pipe, a water filter pipe and a solid pipe connected in sequence; a rubber plug hole sealer is sleeved and fixed on the output end of the drill pipe, and the drill pipe drives the rubber plug hole sealer to enter the solid pipe, so that the rubber plug hole sealer is located at one end of the solid pipe close to the water filter pipe, so that the output end of the drill pipe extends into the water filter pipe; an external driver drives the rubber plug hole sealer to expand, so that the rubber plug hole sealer blocks the solid pipe; the drilling rig drives the circulating fluid through the drill pipe, the water filter pipe and the filling space in sequence through the internal pump, and then flows back to the internal pump to form a circulating flow until the filling space is completed. The technical solution proposed by the present invention avoids the occurrence of cavities in the first water stop material layer, the second water stop material layer and the gravel layer, and maximizes the quality of well formation.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogeological drilling and well formation, and in particular to a hydrogeological drilling hole single-plug positive circulation dynamic water gravel filling and water stopping process. Background Art

[0002] After the completion of the hydrogeological drilling construction, the well construction operation must be carried out. First, the well construction pipes (including sedimentation pipes, water filter pipes, and solid pipes) are lowered, and then the water-stopping and gravel filling materials are filled in sequence between the well construction pipes and the well wall. The water-stopping materials are mainly filled in the non-target aquifer well section; gravel materials are generally selected as gravel materials, which are mainly filled between the target aquifer water filter pipe and the aquifer well wall to create an artificial filter layer to increase the water output, prevent the sand and gravel in the aquifer from entering the water filter pipe, and protect the water filter pipe. Gravel filling and water stopping is an important process in the hydrological well construction process. The quality of this process determines whether the well can be completed and the service life of the well after completion.

[0003] The commonly used method of filling gravel and water-stopping materials is hydrostatic filling. Hydrostatic filling is the filling of liquid between the wellbore and the well wall in a static state. It is suitable for wells with shallow depths and fine-grained formations with large annular gaps. In deep well operations, hydrostatic filling can easily cause bridging blockage between gravel and water-stopping materials, resulting in cavities in the well section filled with annular gaps on the well wall. In the later stage of the blockage section, the collapse of gravel and water-stopping materials can easily cause ground collapse at the wellhead. Summary of the invention

[0004] The main purpose of the present invention is to provide a hydrogeological drilling single plug positive circulation dynamic water gravel filling water stopping process, aiming to solve the problem of preventing bridge formation of cavity during the process of filling gravel and water stopping material.

[0005] To achieve the above purpose, the technical solution proposed by the present invention is:

[0006] A hydrogeological borehole single plug positive circulation dynamic water gravel filling water stopping process, comprising:

[0007] The well-forming tubular is lowered into the borehole to form a filling space between the borehole and the well-forming tubular; the well-forming tubular comprises a sedimentation pipe, a water filter pipe and a solid pipe connected in sequence;

[0008] The rubber plug hole sealer is sleeved and fixed on the output end of the drill rod, and the drill rod drives the rubber plug hole sealer into the real pipe, so that the rubber plug hole sealer is located at one end of the real pipe close to the water filter pipe, so that the output end of the drill rod extends into the water filter pipe;

[0009] An external driver drives the rubber plug hole sealer to expand, so that the rubber plug hole sealer seals the solid pipe;

[0010] The drilling rig drives the circulating fluid through the inner pump to sequentially pass through the drill pipe, the water filter pipe and the filling space, and then flows back to the inner pump to form a circulating flow until the filling space is completely filled with materials.

[0011] Preferably, the material filling includes sequentially filling a first water-stopping material layer, a gravel layer, a second water-stopping material layer and a fixed layer into the filling space; the side of the gravel layer facing the second water-stopping material layer is lower than the end of the water filter pipe away from the solid pipe, and the side of the gravel layer facing the first water-stopping material layer is higher than the end of the water filter pipe away from the sedimentation pipe.

[0012] Preferably, the side of the gravel layer facing the second waterproof material layer is 5m to 10m lower than the end of the water filter pipe away from the solid pipe; the side of the gravel layer facing the first waterproof material layer is 2m to 3m higher than the end of the water filter pipe away from the sedimentation pipe.

[0013] Preferably, the level of the second water-stopping material layer away from the gravel layer is 1m to 2m lower than the wellhead; and the side of the fixed layer away from the second water-stopping material layer is flush with the wellhead.

[0014] Preferably, the first water-stopping material layer and the second water-stopping material layer are both water-stopping ball layers; the water-stopping ball layer comprises a plurality of bentonite water-stopping balls, and the diameter of the bentonite water-stopping balls is 3 cm to 5 cm.

[0015] Preferably, the fixing layer is a cement layer.

[0016] Preferably, the circulating fluid is at least one of water or drilling fluid.

[0017] Preferably, the flow rate of the circulating fluid is 0.6 m / s to 4 m / s.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] By circulating the fluid in the filling space, cavities are avoided in the first water-stopping material layer, the second water-stopping material layer and the gravel layer, so that the sizes of the first water-stopping material layer, the second water-stopping material layer and the gravel layer are close to the ideal values ​​during the actual filling process, thereby maximizing the well completion quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the well-forming tubular being lowered into the borehole;

[0022] Figure 2 It is a structural schematic diagram of the circulation fluid flow;

[0023] Figure 3 This is a schematic diagram of a gravel-filled waterstop structure used for comparison.

[0024] Description of Figure Numbers:

[0025] 1-well pipe; 11-sedimentation pipe; 12-water filter pipe; 13-solid pipe;

[0026] 2-rubber plug sealer; 21-external driver;

[0027] 3- Drill pipe;

[0028] 4-filling space; 41-first waterproof material layer; 42-gravel layer; 43-second waterproof material layer;

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] The invention provides a hydrogeological borehole single-plug positive circulation dynamic water gravel filling water stopping technology.

[0036] Figure 3 A method of filling water-stopping materials and gravel for comparison. Figure 3 The method shown requires filling the first water-stopping material layer 41 in the filling space 4 outside the sedimentation pipe 11, filling the gravel layer 42 in the filling space 4 outside the water filter pipe 12, and filling the second water-stopping material layer 43 in the filling space 4 of the solid pipe 13 in sequence. The commonly used method of filling gravel and water-stopping materials is prone to form cavities. In the later stage, due to structural problems, the cavity will cause the part close to the cavity to collapse directly, which is likely to cause the wellhead ground to collapse, seriously affecting the well completion quality and construction safety.

[0037] like Figure 1 to Figure 2 A hydrogeological borehole single plug positive circulation dynamic water gravel filling water stopping technology shown, comprising:

[0038] Step S10, the well-forming tubular 1 is lowered into the borehole to form a filling space 4 between the borehole and the well-forming tubular 1; the well-forming tubular 1 comprises a sedimentation pipe 11, a water filter pipe 12 and a solid pipe 13 which are sequentially connected along the axial direction of the well-forming tubular 1;

[0039] Step S20, the rubber plug sealer 2 is sleeved and fixed on the output end of the drill rod 3, and the drill rod 3 drives the rubber plug sealer 2 into the solid pipe 13, so that the rubber plug sealer 2 is located at one end of the solid pipe 13 close to the water filter pipe 12, and the output end of the drill rod 3 extends into the water filter pipe 12;

[0040] Step S30, the external driver 21 drives the rubber plug hole sealer 2 to expand, so that the rubber plug hole sealer 2 seals the solid pipe 13;

[0041] Step S40, the drilling rig drives the circulating fluid through the inner pump to sequentially pass through the drill pipe 3, the water filter pipe 12 and the filling space 4, and then flows back to the inner pump to form a circulating flow until the filling space 4 is completely filled with materials.

[0042] By circulating the fluid in the filling space 4, cavities are avoided in the first water-stopping material layer 41, the second water-stopping material layer 43 and the gravel layer 42, so that the sizes of the first water-stopping material layer 41, the second water-stopping material layer 43 and the gravel layer 42 are close to the ideal values ​​during the actual filling process, thereby maximizing the well completion quality.

[0043] Specifically, before step S40, the method further includes:

[0044] Step S50, run the drilling rig internal pump for a preset time period to replace the thick mud in the drill pipe 3 with circulating fluid. Effectively reduce the resistance of filling water-stopping materials and gravel, the circulating fluid flows out from the filter pipe 12, returns to the ground through the filling space 4 (that is, the end of the solid pipe 13 away from the filter pipe 12), and replaces the original thick mud in the well and the drill pipe 3. The circulating fluid returns to the ground and is pumped to the drilling rig internal pump through an external pipeline.

[0045] Specifically, after step S40, the method further includes:

[0046] Step S60, obtain the liquid level data and the liquid level mark height of the wellhead circulating fluid, determine whether the liquid level data is within the liquid level mark height, and when the liquid level data is lower than the liquid level mark height, increase the power of the pump in the drilling rig so that the circulating fluid will flush the bridge joint until the circulating fluid flows normally, so that the pump in the drilling rig returns to normal operating power. When the circulating fluid flows normally, the circulating fluid at the wellhead will remain in a constant state. Only when the water-stop material or gravel fills and settles in the filling space 4, the bridge agglomerates, which will affect the natural flow of the circulating fluid, so by increasing the flow rate of the circulating fluid, the circulating fluid impacts the bridge contact, so that the agglomerates are disintegrated.

[0047] Specifically, the sedimentation pipe 11, the water filter pipe 12 and the solid pipe 13 are connected by threaded connection or joint welding.

[0048] Specifically, the external driver 21 is an external gas source or an external liquid source.

[0049] The material filling includes filling the first water-stopping material layer 41, the gravel layer 42, the second water-stopping material layer 43 and the fixed layer into the filling space 4 in sequence; the side of the gravel layer 42 facing the second water-stopping material layer 43 is lower than the end of the water filter pipe 12 away from the solid pipe 13, and the side of the gravel layer 42 facing the first water-stopping material layer 41 is higher than the end of the water filter pipe 12 away from the sedimentation pipe 11.

[0050] The side of the gravel layer 42 facing the second waterproof material layer 43 is 5m to 10m lower than the end of the filter pipe 12 away from the solid pipe 13; the side of the gravel layer 42 facing the first waterproof material layer 41 is 2m to 3m higher than the end of the filter pipe 12 away from the sedimentation pipe 11.

[0051] Specifically, the diameter of the gravel is adjusted according to the type of aquifer, and the types of aquifers include sandy soil aquifers and sandy soil aquifers.

[0052] Sandy soil aquifer: D is between 6 and 8 times of d1;

[0053] Gravel soil aquifer: When d2<2mm, the value of D is between 6 and 8 times of d2. When d2≥2mm, 10mm to 20mm gravel can be filled.

[0054] Among them, D is the maximum particle diameter when the cumulative sieved weight is 50% in the particle composition of the gravel screening sample; d1 is the maximum particle diameter when the cumulative sieved weight is 50% in the particle composition of the sandy soil aquifer screening sample; d2 is the maximum particle diameter when the cumulative sieved weight is 20% in the particle composition of the crushed stone soil aquifer screening sample.

[0055] The amount of gravel can be calculated using the following formula:

[0056] V = 0.785(B 2 -C 2 ) LK;

[0057] Wherein, V is the gravel filling volume, in cubic meters; C is the hole diameter, in meters; C is the casing outer diameter, in meters; L is the gravel filling height, in meters; K is the over-diameter coefficient, ranging from 1.1 to 1.3.

[0058] The second waterproof material layer 43 is 1m to 2m lower than the wellhead away from the gravel layer 42 ; the side of the fixed layer away from the second waterproof material layer 43 is flush with the wellhead.

[0059] The first water-stop material layer 41 and the second water-stop material layer 43 are both water-stop ball layers; the water-stop ball layer includes a plurality of bentonite water-stop balls, and the diameter of the bentonite water-stop balls is 3 cm to 5 cm. The bentonite water-stop balls are characterized by strong adsorption, durability, fine particles, and easy dispersion, and large water absorption and large gaps between the water-stop balls to facilitate the circulation of the circulating fluid.

[0060] The fixing layer is a cement layer.

[0061] The circulating fluid is at least one of water or drilling fluid. The auxiliary circulation of drilling fluid and water can reduce the bottom sinking resistance of water-stopping materials and gravel.

[0062] The flow rate of the circulating fluid is 0.6m / s to 4m / s. The flow rate control of the circulating fluid can avoid the flow rate being too fast to affect the natural sinking of the water-stopping material and gravel, and avoid the flow rate being too slow to prevent the bridge from forming a cavity.

[0063] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A hydrogeological borehole single plug positive circulation dynamic water gravel filling water stopping process, characterized in that: include: The well-forming tubular is lowered into the borehole so as to form a filling space between the borehole and the well-forming tubular; The well-forming pipe material comprises a sedimentation pipe, a water filter pipe and a solid pipe connected in sequence; The rubber plug hole sealer is sleeved and fixed on the output end of the drill rod, and the drill rod drives the rubber plug hole sealer into the real pipe, so that the rubber plug hole sealer is located at one end of the real pipe close to the water filter pipe, and the output end of the drill rod extends into the water filter pipe; An external driver drives the rubber plug hole sealer to expand, so that the rubber plug hole sealer seals the solid pipe; The drilling rig drives the circulating fluid through the inner pump to sequentially pass through the drill pipe, the water filter pipe and the filling space, and then flows back to the inner pump to form a circulating flow until the filling space is completely filled with materials; Obtain the liquid level data and the liquid level mark height of the wellhead circulating fluid, and determine whether the liquid level data is within the liquid level mark height. When the liquid level data is lower than the liquid level mark height, increase the power of the pump in the drilling rig so that the circulating fluid can flush the bridge, until the circulating fluid flows normally, so that the pump in the drilling rig can return to normal operating power; The material filling includes sequentially filling a first waterproof material layer, a gravel layer, a second waterproof material layer and a fixing layer into the filling space; The circulating fluid is at least one of water or drilling fluid; The flow rate of the circulating fluid is 0.6 m / s to 4 m / s; The second waterproof material layer is 1m to 2m lower than the wellhead away from the gravel layer; the side of the fixed layer away from the second waterproof material layer is flush with the wellhead; The first water-stop material layer and the second water-stop material layer are both water-stop ball layers; the water-stop ball layer comprises a plurality of bentonite water-stop balls, and the diameter of the bentonite water-stop balls is 3 cm to 5 cm; The fixing layer is a cement layer.

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