Sand washing system for oil field sand control pipe
By designing an oilfield sand control pipe sand flushing system, the drill bit is used to drill through the drillable plug to remove the sand and gravel inside and outside the sand control pipe, thus solving the problem of sand control pipe blockage and achieving the effect of simplifying construction, reducing costs and improving production efficiency.
Patent Information
- Application Number
- CN202422839644.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2034-11-21
AI Technical Summary
In existing mechanical sand control technology, the annulus between the outer wall of the sand control tube and the wellbore is easily filled with gravel, causing the sand control tube to be blocked, increasing oil flow resistance, causing oil well production to be reduced or even shut down, and overhaul operations have a long construction period and high cost, affecting the production of adjacent wells.
An oilfield sand control pipe sand flushing system is designed, which includes a sand control pipe, a drill pipe, a drill bit and a flushing assembly. The drill bit drills through the drillable plug, and gravity and liquid flow are used to flush out the annular space sand and gravel, simplifying the sand control pipe salvage process, shortening the construction period and reducing costs.
Effectively remove sand and gravel inside and outside the sand control pipe, simplify the fishing process, shorten the construction period, reduce costs, avoid production stoppage of adjacent wells and damage to downhole equipment, and improve oil well production efficiency.
Smart Images
Figure CN223423956U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of oil well sand control, in particular to an oil field sand control pipe sand flushing system. Background Art
[0002] There are loose sandstone reservoirs in the oil field. This type of reservoir is shallowly buried, loosely cemented, has poor diagenesis, and suffers from serious sand production during development. Therefore, it is very important to carry out oil well sand control during the development and production of this type of reservoir. Only effective sand control can ensure the normal production of the oil well.
[0003] In the existing technology, sand control is mainly based on mechanical sand control, accounting for 95% of sand control wells. The mechanical sand control method is to place sand control pipes in oil and water wells to prevent sand from penetrating the formation. However, after a long time, the annulus between the outer wall of the sand control pipe and the wellbore will be filled with gravel, and some sand will penetrate the sand control pipe and fill the oil layer. If the liquid flow in the well cannot bring all the sand to the surface, the sand in the sand control pipe will gradually settle, the sand column will increase, and the oil outlet channel will be blocked, which will cause the sand control of the oil well to expire, increase the oil flow resistance, reduce or even stop the oil well production, and damage the downhole equipment, causing downhole sand jam accidents, resulting in sand control failure.
[0004] When sand control fails in an oil well, the traditional approach is to overhaul the well by milling, fishing, and winding. However, due to the gravel inside and outside the sand control pipe, which is completely buried in the gravel, milling, fishing, and winding takes a long time, causes significant damage to the pipe string, and is expensive. Furthermore, since most oilfield wells operate in a well-separated production model, overhaul operations require a large area and demand high wellsite conditions. This requires shutting down or removing adjacent wells, impacting normal production. Furthermore, to accommodate the overhaul, farmland must be occupied, requiring new land acquisition and incurring high labor and agricultural costs. In addition, the construction cost of overhaul operations is high. The average cost of an overhaul and winding construction in a certain oil field is 250,000 yuan per well. Based on 30 wells, the annual cost savings is 7.5 million yuan; the overhaul construction cycle is long, and the long occupancy period of the overhaul well and the surrounding adjacent wells affects the crude oil production of many production wells; the casing milling used in overhaul operations causes great damage to the casing, especially in directional wells, which are easily damaged when the alloy casing milling barrel is used for casing milling; after the casing milling is completed, the salvage process must continue, and the uncertainty of downhole salvage is complex salvage.
[0005] Therefore, it is very necessary to remove the sand and gravel inside and outside the sand control pipe to facilitate the subsequent pulling and winding construction of the sand control pipe. Summary of the Invention
[0006] The purpose of the utility model is to provide an oilfield sand control pipe sand flushing system to address the deficiencies of the existing technology, and to remove sand and gravel inside and outside the sand control pipe.
[0007] The technical solution adopted by the utility model is: an oilfield sand control pipe sand flushing system,
[0008] including sand control pipe, drill pipe and drill bit, and flushing assembly;
[0009] The sand control pipe is arranged in the wellbore, and a packer is arranged between the outer wall of the upper end of the sand control pipe and the inner wall of the wellbore.
[0010] The upper end of the drill pipe is connected with the power equipment of the wellhead.
[0011] The lower end of the drill pipe is connected with the upper end of the drill bit.
[0012] The drill bit penetrates the sand control pipe, and the lower end of the sand control pipe is provided with a drillable plug.
[0013] The flushing assembly comprises a liquid inlet pipeline, a backflow pipeline and a circulating pool; the outlet end of the liquid inlet pipeline is in communication with the inside of the wellbore, and the inlet end of the liquid inlet pipeline is in communication with the circulating pool arranged outside the wellhead; the inlet end of the backflow pipeline is located at the bottom of the drill bit, and the outlet end of the backflow pipeline is in communication with the circulating pool.
[0014] According to the above scheme, the drillable plug is made of peek material.
[0015] According to the above scheme, the drill bit is provided with a flow guide groove, and the flow guide groove extends to the lower end surface of the drill bit.
[0016] According to the above scheme, the backflow pipeline is arranged inside the drill bit and the drill pipe; the upper end of the backflow pipeline is in communication with the circulating pool through a ground pipeline.
[0017] According to the above scheme, the drill bit and the drill pipe are hollow and in communication with each other, forming a channel as the backflow pipeline; the upper end of the channel of the drill pipe is connected with the ground pipeline in communication with the circulating pool; the lower part of the channel of the drill bit is provided with a communication hole connected with the flow guide groove.
[0018] According to the above scheme, the drillable plug has a hollow cylindrical structure with a closed lower end and an open upper end; the upper end of the drillable plug is threadedly connected with the lower end of the sand control pipe.
[0019] According to the above scheme, the sand control pipe is a wire-wound sand control pipe.
[0020] According to the above scheme, the drill bit is made of hard alloy material.
[0021] The beneficial effects of the present application are as follows:
[0022] 1. The drillable plug is designed at the lower end of the sand control pipe, and when the wire-wound sand control pipe needs to be pulled out, the drill pipe with the drill bit is lowered to the bottom of the sand control pipe, the flushing assembly is started, the drill bit drills through the drillable plug, and the annular sand and gravel falls below the sand control pipe under the gravity and the scouring of the liquid flow, and is carried out of the wellbore by the sand flushing liquid, so that the purpose of removing the annular sand and gravel is achieved, and subsequent wire-wound construction is facilitated.
[0023] 2. The utility model has a simple structure and is easy to operate. The utility model can effectively simplify the fishing process of the sand control pipe, shorten the pulling and winding construction operation cycle, save the construction cost of a single well, and at the same time avoid the impact on the suspension of production of adjacent wells and avoid damage to the sand control pipe. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a structural schematic diagram of a specific embodiment of the utility model.
[0025] Figure 2 Schematic diagram of the working state of this embodiment.
[0026] Figure 3 Schematic diagram of the structure of the drill bit in this embodiment.
[0027] Figure 4 Schematic diagram of the pipeline connection of the flushing assembly in this embodiment.
[0028] Among them: 1. Drill bit; 1.1. Diversion groove; 2. Drillable plug; 3. Drill pipe; 4. Sand control pipe; 5. Packer; 6. Oil layer; 7. Gravel; 8. Liquid inlet pipeline; 9. Pump truck; 10. Circulating pool; 11. Surface pipeline; 12. Passage inside the drill pipe; 13. Inside the wellbore. DETAILED DESCRIPTION
[0029] In order to better understand the present invention, the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0030] like Figure 1 and Figure 2 An oilfield sand control pipe sand flushing system is shown.
[0031] It includes a sand control tube 4, a drill rod 3 and a drill bit 1, as well as a flushing assembly;
[0032] The sand control pipe 4 is arranged in the wellbore of the oil well, and a packer 5 is arranged between the upper outer wall of the sand control pipe 4 and the inner wall of the wellbore;
[0033] The upper end of the drill rod 3 is connected to the power equipment at the wellhead, and the power equipment is used to drive the drill rod 3 to rotate;
[0034] The lower end of the drill rod 3 is connected to the upper end of the drill bit 1;
[0035] The drill bit 1 passes through the sand control tube 4, and the lower end of the sand control tube 4 is provided with a drill plug 2;
[0036] The flushing assembly includes a liquid inlet pipe 8, a return pipe and a circulation pool 10; the inlet end of the liquid inlet pipe 8 is connected to the circulation pool 10 outside the wellhead (specifically, through a ground pipe 13), and the outlet end of the liquid inlet pipe 8 is connected to the inside of the oil wellbore 13; the inlet end of the return pipe is located at the bottom of the drill bit 1, and the outlet end of the return pipe is connected to the circulation pool 10, as shown in FIG. Figure 4 shown.
[0037] In the present invention, the sand control pipe 4 is specifically a wire-wound sand control pipe, which includes a pipe column body and a screen sleeved on the pipe column body, and the screen is located in the oil layer 6; a drillable plug 2 is provided at the lower end of the sand control pipe to seal the gravel 7 at the bottom of the sand control pipe 4.
[0038] In the present invention, the drill rod 3 is threadedly connected to the drill bit 1. The outer diameter of the drill rod 3 matches the inner diameter of the production wellbore and the requirements of sand flushing operations, while the torque meets the design requirements. The connecting end of the drill rod 3 (the end connected to the drill bit 1) is chamfered to prevent the drill from getting stuck after penetrating the drillable plug 2. The power equipment drives the drill bit 1 through the drill rod 3, and the drill bit 1 can drill through the drillable plug 2 at the lower end of the sand control pipe.
[0039] In the present invention, the power equipment may be the hydraulic pliers described below.
[0040] Preferably, if Figure 3 As shown, the drill bit 1 is provided with a guide groove 1.1, which extends to the lower end surface of the drill bit 1.
[0041] In the utility model, when the drill bit 1 is driven downward by the drill rod 3 of the drilling rig to drill into the drillable plug, the sand flushing liquid in the liquid inlet pipeline 8 is poured into the wellbore, flows to the lower part of the drill bit 1 through the guide groove 1.1, and the gravel 7 around the drill bit 1 and the broken materials of the drillable plug are promptly flushed away during drilling.
[0042] In the present invention, the return line is arranged inside the drill bit 1 and the drill rod 3 ; the upper end of the return line is connected to the circulation pool 10 through the ground pipeline 11 .
[0043] Preferably, the drill bit 1 and the drill rod 3 are hollow inside and interconnected to form a channel serving as a return line; the upper end of the channel 12 of the drill rod 3 is connected to a ground pipe 12 connected to the circulation pool 10; the lower part of the channel of the drill bit 1 has a connecting hole connected to the guide groove 1.1.
[0044] In the present invention, the sand flushing fluid in the wellbore carries the sand and gravel 7 and flows back to the circulation pool 10 outside the wellhead through the channels inside the drill bit 1 and the drill rod 3 and the surface pipeline 12.
[0045] Preferably, the drill bit 1 is made of cemented carbide material.
[0046] The special drill bit 1 is made of hard alloy, and the speed of drilling through the plug is improved.
[0047] Preferably, the drillable plug 2 is a columnar structure with a closed lower end, an open upper end and a hollow interior; the upper end of the drillable plug 2 is threadedly connected to the lower end of the sand control pipe 4, and specifically, an internal thread is formed on the inner circumferential surface of the upper end of the drillable plug 2, and an internal thread that is adapted to the internal thread is formed on the outer circumferential surface of the bottom of the sand control pipe 4.
[0048] In the utility model, the thread pressure strength of the drillable plug 2 reaches the design standard requirement, and the anti-slip ability reaches the design requirement, so that the drillable plug 2 is prevented from slipping under heavy load; meanwhile, the drillable plug 2 has the characteristic of being easy to drill through.
[0049] In the utility model, the drillable plug 2 is made of peek material. Peek is a new type of thermoplastic engineering plastic, and has very excellent physical and mechanical properties.
[0050] The three-step method of "drilling the pipe string, cleaning sand in the annulus and making up the connection to fish" is adopted to realize the fishing of the sand control pipe 4, and the specific process is as follows:
[0051] (1) plug setting: the slickline is set to the designated depth, and the plug is required to be set in place; the well is shut in for 24 hours, and the plug surface is rechecked and the standard pressure is verified to be qualified before the plug setting pipe string is pulled out;
[0052] (2) sand control: the sand control pipe is set to the designed position according to the sand control pipe combination and the pipe string schematic diagram, and the sand control operation is performed;
[0053] (3) drilling and sand washing: the drill pipe 3 and the drill bit 1 are lowered to the drillable plug 2, the water hose is connected to the pump truck 9 on the ground, the pump is started to backwash, the pump pressure is controlled to be set at a pressure, the hydraulic tong is used as the power, the pipe is slowly lowered by rotating clockwise, the specified drilling pressure is maintained, the sand in the sand control pipe string 4 is continuously washed, the drill bit 1 continues to drill downward to drill the drillable plug 2, the drill bit 1 continues to lower to wash sand to a distance of several meters below the bottom of the drillable plug 2, the sand is carried to the ground circulation tank 10 by the water flow, the sand below the drillable plug 2 is emptied, and in this process, the sand in the annulus between the outer wall of the sand control pipe 4 and the well wall is in an unsupported state, and falls below the sand control pipe 4 under the action of gravity and the flow of the washing liquid, and is carried out of the wellbore by the washing liquid, at this time, the sand control pipe 4 is in a suspended state.
[0054] (4) pulling out: the corresponding fishing spear is lowered, the suspended packer 5 is pulled out to release the seal, and all the sand control pipes 4 in the well are fished out.
[0055] The plug setting, sand control and pulling out procedures in the above process are the existing conventional technologies in the industry, and will not be described herein.
[0056] The contents not described in detail in the specification belong to the prior art known to those skilled in the art.
[0057] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. An oilfield sand control pipe sand flushing system, characterized in that: Includes sand control pipes, drill pipes and drill bits, as well as flushing components; The sand control pipe is arranged in the wellbore of the oil well, and a packer is arranged between the upper outer wall of the sand control pipe and the inner wall of the wellbore; The upper end of the drill pipe is connected to the power equipment at the wellhead; The lower end of the drill rod is connected to the upper end of the drill bit; The drill bit passes through the sand control tube, and the lower end of the sand control tube is provided with a drill plug; The flushing assembly includes a liquid inlet pipeline, a return pipeline and a circulation pool; the outlet end of the liquid inlet pipeline is connected to the inside of the oil wellbore, and the inlet end of the liquid inlet pipeline is connected to the circulation pool provided outside the wellhead; the inlet end of the return pipeline is located at the bottom of the drill bit, and the outlet end of the return pipeline is connected to the circulation pool provided outside the wellhead.
2. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The drillable plug is made of peek material.
3. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The drill bit is provided with a guide groove which extends to the lower end surface of the drill bit.
4. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The return flow pipeline is arranged inside the drill bit and the drill rod; the upper end of the return flow pipeline is connected to the circulation pool through a ground pipeline.
5. The oilfield sand control pipe sand flushing system according to claim 3, characterized in that: The drill bit and the drill rod are both hollow inside and interconnected to form a channel serving as a return line; the upper end of the channel of the drill rod is connected to a ground pipeline connected to a circulation pool; the lower part of the channel of the drill bit has a connecting hole connected to the guide groove.
6. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The drillable plug is a columnar structure with a closed lower end, an open upper end and a hollow interior; the upper end of the drillable plug is threadedly connected to the lower end of the sand control pipe.
7. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The sand control pipe is a wire-wound sand control pipe.
8. The oilfield sand control pipe sand flushing system according to claim 1, characterized in that: The drill bit is made of hard alloy material.