CN218581591U - General polymer injection well pipe column - Google Patents

Abstract

The utility model discloses a cage system annotates and gathers well tubular column, including sleeve pipe and oil pipe, be connected with the screen pipe in the oil pipe bottom, the screen pipe lower extreme is connected with the plug, is connected with at the oil pipe middle part and has the profile control ware of preventing returning and spitting the runner passageway, has well liquid check valve at the oil pipe sub-unit connection, and the oil pipe inner wall has wear-resisting polyethylene inside lining or has to plate and ooze the anticorrosive scale control coating of tungsten alloy, prevents returning and spitting the runner passageway and be greater than 30 mm's oval passageway for the diameter. And a packer is arranged on the outer wall of the oil pipe. The utility model provides a when annotating and gathering the system pump shutdown maintenance, when single well pipeline perforates well bore pressure reduction leads to the stratum to return and tell the problem. The related testing, well washing, injection and other work are not affected by the throwing and fishing anti-backflow core. The tube detection period can be effectively prolonged, and the production cost is saved. The problems that the instrument falls into the well and cannot be salvaged, foreign matters such as dirty oil micelle impurities in a shaft enter an oil pipe in the well completion process and the like are solved in the design of the pipe column.

Description

General polymer injection well pipe column

Technical Field

The utility model relates to an oil and natural gas exploitation technical field, in particular to general notes gather well tubular column.

Background

Most oil fields in the east of China are in a high water content exploitation stage nowadays, a large amount of petroleum is difficult to exploit, and water injection exploitation also enters a high water content and high exploitation degree stage. In order to solve the problem, tertiary oil recovery is generated at the same time. Polymer flooding is one of the important methods for tertiary oil recovery, namely, high molecular polymers are added into injected water to increase the viscosity of the injected water and reduce the water-phase permeability of an oil layer, so that the water-oil mobility ratio is improved, the injection profile is adjusted to enlarge the swept volume, the macroscopic swept efficiency is improved, and the crude oil recovery rate is further improved. The polymer injection method can be divided into general water injection and separated layer water injection according to the water distribution property. The system is injected into the well without layering, and multiple layers are combined together, and the system is injected with water under the same pressure. The water injection well of the system only puts a smooth oil pipe in the casing so as to achieve the purposes of protecting the casing, establishing an injected water circulation system, facilitating control, saving the input cost of the oil pipe and the like.

In the prior art, as shown in fig. 1, a conventional injection well only has a bare oil pipe 22 put into a casing 21, and the end of the oil pipe 22 is completed with a bell 23, and the bell 23 is generally positioned at the upper end of an oil reservoir. During normal injection, the system incoming liquid is measured by a wellhead control instrument and then injected into the stratum through the oil pipe 22 through the flow of the wellhead Christmas tree to supplement the energy of the stratum 24 and the stratum 25.

In the field implementation process, at least the following problems exist in the prior related art: 1. the ground injection system of the polymer injection well has no return-spit prevention function: in the process of a polymer injection well pipeline, a wellhead is not provided with a check valve and a check valve in order to reduce viscosity loss, so that the conventional polymer injection well ground injection system has no backflow prevention function. Therefore, when a polymer injection system stops pumping and maintenance, and a ground pipeline is not perforated and leaked to find and treat in time, the polymer injection well pressure in a pipe network is different, so that the well is caused to flow backwards, at the moment, the pressure of a well with higher pressure is reduced due to the reduction of the pressure of a well head, the formation pressure is higher than the injection pressure of a well shaft, the polymer injected in a stratum returns outwards to the well shaft, the polymer returning to the well shaft can carry a plurality of micelles, a sand layer is loosened in some stratums, the polymer with higher viscosity can also aggravate the carrying of a large amount of stratum sand to return to the well shaft, the injection capacity of the polymer injection well is seriously influenced by the micelle and the stratum sand, even the sand is buried in the oil layer, the injection of the polymer injection well is prevented from entering, and the development of the oil reservoir is influenced. 2. The polymer injection well shaft has no backflow prevention function, and an backflow prevention flushing valve or a profile control device with a backflow prevention flow channel is usually adopted in the injection well shaft to play a role in backflow prevention, but the viscosity of a polymer solution is reduced due to large shearing of a tool to influence the polymer flooding effect, so that the polymer injection well shaft is not suitable for a general polymer injection well, and the backflow prevention function is not realized. 3. The single effect of measures is poor after polymer micelle and formation sand return to a shaft in the existing general polymer injection well, and because the horn mouth of the existing pipe column is positioned on a stratum, the return spitting object can be squeezed into the stratum again only in an injection increasing mode of a high-pressure pump truck after the polymer micelle and the formation sand return to the shaft, the effect is difficult to be achieved after the sand buries an oil layer, and the cost investment is high. 4. The pipe column is easy to scale and stick polymer micelle, so that the logging instrument is blocked or stuck when meeting, and the logging instrument falls into the well. Because the bottom of the existing pipe column is a horn mouth, the logging instrument falls into the casing, the fishing difficulty is increased, even the instrument falling accident is caused, the instrument cannot be fished out, and the construction difficulty of shaft measures is increased. 5. Foreign matters such as dirty oil micelle impurities in the shaft enter the oil pipe to influence the later-stage test fishing.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that, a gather well tubular column is annotated to cage system is provided, return to telling the instrument through increasing the pit shaft and solve and cause stratum polymer micelle, stratum sand to return to telling and cause the polymer to annotate and not and then influence and annotate and gather well injection effect when reducing suddenly because of well head pressure.

In order to solve the technical problem, the utility model discloses a technical scheme be: a general polymer injection well string comprises a casing and an oil pipe, wherein the bottom of the oil pipe is connected with a sieve pipe, the lower end of the sieve pipe is connected with a plug, the middle of the oil pipe is connected with a profile control device with an anti-return flow passage, the lower part of the oil pipe is connected with a well fluid check valve, the inner wall of the oil pipe is provided with a wear-resistant polyethylene lining or a tungsten alloy plating anti-corrosion and anti-scale coating, and the anti-return flow passage is an oval passage with the diameter larger than 30 mm.

And a packer is arranged on the outer wall of the oil pipe.

The oil pipe and the profile control device, the oil pipe and the well fluid check valve, the oil pipe and the sieve pipe and the plug are fixedly connected through screw threads.

The packer is fixedly connected with the oil pipe through a screw thread.

The beneficial effects of the utility model are that: the problem of stratum return spitting caused by reduction of wellbore pressure when a polymer injection system stops pumping and maintenance and a single well pipeline is perforated is solved. The related testing, well washing, injection and other work are not affected by the throwing and fishing anti-backflow core. The tube detection period can be effectively prolonged, and the production cost is saved. The problems that the instrument falls into the well and cannot be salvaged, foreign matters such as dirty oil micelle impurities in a shaft enter an oil pipe in the well completion process and the like are solved from the design of the pipe column.

Drawings

FIG. 1 is a schematic view of a prior art general injection well string.

Figure 2 is a schematic view of a general polymer injection well string of the present invention.

Figure 3 is a schematic view of a general polymer injection well string according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by a person skilled in the art without any inventive step are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "provided", "sleeved/connected", "connected", and the like, are to be interpreted broadly, such as "connected", which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in figure 2, the utility model discloses a general notes gather well tubular column, including sleeve pipe 2 and oil pipe 1, be connected with screen pipe 15 in oil pipe 1 bottom, screen pipe 15 lower extreme is connected with plug 16, is connected with at oil pipe 1 middle part and has the profile control ware of preventing returning and spitting runner passageway 9, has the well liquid check valve at oil pipe 1 sub-unit connection, and oil pipe 1 inner wall has wear-resisting polyethylene inside lining or has to plate and ooze the anticorrosive scale control coating of tungsten alloy, prevents returning and spitting runner passageway 9 and be greater than 30 mm's oval passageway for the diameter.

And a packer 6 is arranged on the outer wall of the oil pipe 1. The packer 6 is fixedly connected with the oil pipe 1 through a screw thread.

The oil pipe and the profile control device, the oil pipe and the well fluid check valve, the oil pipe and the sieve pipe 15, and the sieve pipe 15 and the plug 16 are fixedly connected through screw threads.

The utility model discloses the well is gathered to annotate in general adopts inside lining or coating oil pipe to reduce the tubular column scale deposit, glue the logging instrument that the glutinous polymer micelle caused and meet and hinder, meet the card phenomenon, increase the oil pipe and go into the degree of depth down, and change original horn mouth well completion mode, make abnormal well is gathered in general notes well solution is more targeted, it is more simple and convenient effective, prevent that the logging instrument from falling into in the sleeve pipe, and still increase well liquid non return device, prevent that foreign matters such as sump oil micelle impurity in the well completion in-process pit shaft from getting into oil pipe, the range of application is wider. The utility model discloses can solve the general notes gather well pit shaft and return to tell the injection well who causes and annotate not advance, logging instrument meets the resistance, meets the card, falls the well, abnormal notes gather well solution single scheduling problem.

The lining or inner coating oil pipe 2 is a special oil pipe, the inner wall of the special oil pipe is provided with a wear-resistant polyethylene lining or a plated and infiltrated tungsten alloy anti-corrosion and anti-scaling coating, the wear-resistant polyethylene lining or the plated and infiltrated tungsten alloy anti-corrosion and anti-scaling coating can prevent the shaft shrinkage condition caused by oil pipe internal scaling and polymer adhesion, and can effectively prevent the logging instrument from blocking and blocking.

The oil layer I3, the oil layer II 4 and the oil layer III 5 can be oil reservoir development oil layers, and are normal polymer injection oil layers at present.

The first oil layer 3 can also be a non-developed injection stopping or casing leakage point, and an injection point is not needed.

The blocking layer or blocking leakage packer 6 can block and separate the currently undeveloped stop injection or casing leakage point and the unnecessary injection point. The blocking layer or blocking leakage packer 6 is fixedly connected with the inner lining or inner coating oil pipe 1 through a screw thread.

The profile control device comprises a profile control device main body 7 with an anti-backflow flow passage, an anti-backflow large flow passage 9 and an anti-backflow inner cylinder 10, wherein the profile control device main body 7 with the anti-backflow flow passage is fixedly connected with the lining or the inner coating oil pipe 1 through a screw thread. The anti-backflow throwing and fishing core 8 is a throwing and fishing tool and can be placed into the anti-backflow inner barrel 10 or taken out of the anti-backflow inner barrel 10 in a steel wire throwing and fishing mode.

When the backflow-preventing throwing and fishing core 8 is not thrown into the backflow-preventing inner cylinder 10, the backflow-preventing inner cylinder 10 is hollow to form a hollow shaft channel, and at the moment, the backflow-preventing large flow channel 9 is closed and is not opened.

The backflow-preventing throwing core 8 can be fixed in the backflow-preventing inner cylinder 10 when being thrown into the backflow-preventing inner cylinder. The backflow-preventing throwing and fishing core 8 can seal the hollow space in the backflow-preventing inner cylinder 10 when being fixed in the backflow-preventing inner cylinder 10, prevent polymer solution in a shaft from flowing downwards from the backflow-preventing inner cylinder 10, and prevent fluid below the backflow-preventing inner cylinder 10 from flowing upwards.

The anti-backflow throwing and fishing core 8 can also be used for fishing the anti-backflow throwing and fishing core 8 out of the anti-backflow inner barrel 10 through a special fishing tool.

The backflow-preventing large-flow-channel 9 is arranged on the upper portion of the profile control device main body 7 and is an oval channel with the diameter larger than 30mm, the large-flow-channel between the interior of an oil pipe and the annular space of an oil sleeve can be established, polymer solution is not sheared at all, and the injection effect of the polymer solution can be guaranteed.

The backflow-preventing inner cylinder 10 is arranged in the profile control device main body 7 and can move up and down along the axial direction of the shaft under the action of the backflow-preventing throwing and fishing core 8, so that the backflow-preventing large flow passage 9 is opened or closed.

The process of opening the backflow-preventing large flow passage 9 is as follows: when the anti-backflow casting and fishing core 8 is thrown into the anti-backflow inner cylinder 10 for fixing, the polymer solution injected into the polymer injection well can enable the anti-backflow inner cylinder 10 to move downwards through the anti-backflow casting and fishing core 8, the anti-backflow large flow channel 9 is exposed, the anti-backflow large flow channel 9 is completely opened at the moment, the polymer solution enters the annular space of the oil jacket through the anti-backflow large flow channel 9, and therefore the polymer solution is injected into the stratum, and the normal injection state is achieved at the moment.

The process of closing the backflow-preventing large flow passage 9 is as follows: when the anti-backflow throwing and fishing core 8 is thrown into the anti-backflow inner cylinder 10 for fixation, at the moment, when a wellhead injection system stops pumping maintenance or a ground pipeline is not subjected to timely detection and treatment of perforation leakage, the pressure of a polymer solution in a shaft is gradually reduced, when the pressure of the polymer solution in the shaft is lower than the pressure of an annular space of an oil jacket, the anti-backflow inner cylinder 10 moves upwards under the action of a profile control device main body 7 with an anti-backflow runner channel, so that a large backflow-preventing runner channel 9 is closed, a communication channel between the shaft and the annular space of the oil jacket is cut off, the polymer solution micelle and the formation sand are prevented from flowing backwards, and at the moment, the anti-backflow working state is realized.

The well fluid check valve consists of a well fluid check valve body 11, a sealing ball 12, a shear pin 13 and a push rod 14. The well fluid check valve main body 11 is fixedly connected with the oil pipe 1 through screw threads. The sealing ball 12 may function as a seal in cooperation with a ball seat on the well fluid check valve body 11. The upper end of the push rod 14 props and fixes the sealing ball 12 in a ball seat on the well fluid check valve main body 11, seals an oil sleeve annular space, and prevents foreign matters such as dirty oil micelle impurities in a shaft from entering an oil pipe. Push rod 14 passes through shear pin 13 with well liquid check valve main part 11 and fixes, and it is sealed through the sealing washer between push rod 14 and the well liquid check valve main part 11 simultaneously, plays and prevents that foreign matter such as sump oil micelle impurity in the pit shaft from getting into in the oil pipe. The shear pin 13 can be sheared under the action of external force, so that the push rod 14 is separated from the well fluid check valve body 11.

Compared with the common water injection well sieve tube, the sieve tube 15 for the polymer injection well is mainly characterized in that the aperture of the sieve tube is enlarged and is a circular channel with the diameter of 30mm, a large flow channel with an oil sleeve annular space inside an oil tube can be established, polymer solution is not sheared at all, the injection effect of the polymer solution can be guaranteed, when the anti-return-flow throwing and fishing core 8 is not thrown into the anti-return-flow inner cylinder 10, the anti-return-flow large flow channel 9 is closed, the polymer solution in a shaft can enter the oil sleeve annular space through the sieve tube 15 for the polymer injection well, and therefore the polymer solution is injected into a stratum and does not affect well logging. The screen pipe 15 for the polymer injection well is fixedly connected with the inner lining or inner coating oil pipe 1 through screw threads.

The pipe plug 16 is arranged at the tail end of the pipe column and is fixedly connected with the screen pipe 15 for the polymer injection well through screw threads, so that the logging instrument is prevented from falling into the bottom of the well after being blocked.

The field working process comprises the following steps:

a pipe column connection:

1. at present, when an undeveloped injection stopping or casing leakage point exists and an injection point is not needed, an oil pipe 2 with a fixed lining or coating, a blocking layer or blocking leakage packer 6, a profile control device main body 7 with a backflow-preventing runner passage and a well fluid check valve main body 11 are sequentially connected, a sealing ball 12 is filled in the sealing ball 12, the sealing ball 12 is tightly propped by a push rod 14, the push rod 14 is fixed by a shear pin 13, then a polymer injection well screen pipe 15 and a plug 16 are installed behind the well fluid check valve main body 11 and are required to be put into a well, the blocking layer or blocking leakage packer 6 is positioned between an oil layer I3 and an oil layer II 4, the profile control device main body 7 with the backflow-preventing runner passage is positioned between the blocking layer or blocking leakage packer 6 and the polymer injection well screen pipe 15, can be positioned at the upper end and can also be positioned at the lower end, and the oil layer II 4 and the oil layer III 5 are not required to be aligned to the right; if the depth of the sleeve 2 at the lower part of the oil layer III 5 is enough, namely the pocket is deep enough, the profile control device main body 7 with the backflow-preventing flow passage can be lowered into the lower part of the oil layer III 5 by about 30-50 m; the screen pipe 15 for the polymer injection well is always positioned at the lower part of the oil layer III 5, and abnormal injection conditions caused by deposition of a small amount of polymer micelle, formation sand and oil sludge and dirt substances in a shaft can be solved through well washing; the plug 16 is located immediately behind the screen 15 for the cementing well.

2. At present, when an undeveloped injection stopping or casing leakage point does not exist and an injection point is not needed, a lining or coating oil pipe 1, a blocking layer or blocking leakage packer 6, a profile control device main body 7 with a backflow-preventing runner channel and a well fluid check valve main body 11 are sequentially connected and fixed, a sealing ball 12 is filled in the sealing ball 12, the sealing ball 12 is tightly propped by a push rod 14, the push rod 14 is fixed by a shear pin 13, then a polymer injection well screen pipe 15 and a plug 16 are installed behind the well fluid check valve main body 11, and the profile control device main body 7 with the backflow-preventing runner channel is located at about 50m of the lower part of a well mouth, so that the backflow-preventing and fishing core 8 can be conveniently and quickly fished, and the well logging work can be quickly carried out. The screen pipe 15 for the polymer injection well is always positioned at the lower part of the oil layer III 5, and abnormal injection conditions caused by deposition of a small amount of polymer micelle, formation sand and oil sludge and dirt substances in a shaft can be solved through well washing; the plug 16 is located immediately behind the screen 15 for the cementing well.

2. Setting and injecting: after a shaft tool is put in place, clear water is filled in the oil pipe 1, the shaft tool is pressed by a pump truck, the sealing ball 12 moves downwards under the action of pressure in the oil pipe 1, the push rod 14 also moves downwards under the action of pressure in the oil pipe 1, the shear pin 13 is sheared under the condition of double acting force, the sealing ball 12 and the push rod 14 fall into the tail end of the sieve pipe 15 along the trend, meanwhile, an overflowing channel between the oil pipe 1 and an annular space of an oil sleeve is established, and a packer is set under the action of pressure when the packer is arranged. And then well connecting a wellhead flow, and performing injection test according to injection allocation requirements.

3. The return-spitting prevention throwing and fishing core: after the injection pressure and water amount are stable, the backflow-preventing throwing and fishing core 8 is fixedly arranged on the profile control device main body 7 with the backflow-preventing flow passage.

4. Opening an anti-backflow injection channel: when normally annotating, pour into from oil pipe into, the polymer solution of annotating that the polymer well was annotated this moment can make through preventing returning to tell throwing and dragging for core 8 and prevent returning to tell inner tube 10 and move down, expose and prevent returning to tell big runner passageway 9, prevent returning to tell big runner passageway 9 this moment and all open, polymer solution gets into oil jacket annular space through preventing returning to tell big runner passageway 9 to pour into the stratum.

5. Closing the backflow-preventing injection channel: when a polymer injection system of a wellhead injection system stops pumping maintenance or a ground pipeline is not perforated and leaked and is not found in time for treatment, the pressure of a polymer solution of a shaft is gradually reduced, when the pressure of the polymer solution of the shaft is lower than the pressure of an annular space of an oil sleeve, the backflow-preventing inner cylinder 10 moves upwards under the action of the profile control device main body 7 with the backflow-preventing flow channel, so that the backflow-preventing large flow channel 9 is closed, a communication channel between the shaft and the annular space of the oil sleeve is cut off, the polymer solution micelle of a stratum and stratum sand are prevented from being discharged back, and the stratum backflow field is stopped.

6. Opening a test channel: because the logging tool instrument can measure relevant data information only when the logging tool instrument passes through the lower part of an oil layer, the anti-return-flow throwing and fishing core 8 can be directly lowered into the logging tool for testing when positioned below the layer; when the anti-return-flow casting and fishing core 8 is positioned at the upper part of the oil layer, the anti-return-flow casting and fishing core 8 can be fished out and then put into a logging instrument for testing; and after the test is finished, the anti-return throwing and fishing core 8 is thrown in again.

7. Opening a well washing channel: when the well needs to be washed, the profile control core 6 is directly fished out, and the well is thrown again after the well is washed.

In summary, the present invention is not limited to the above embodiments, and other embodiments can be easily proposed by those skilled in the art within the technical teaching of the present invention, but all such embodiments are included in the scope of the present invention.

Claims (4)

1. The utility model provides a general notes gather well tubular column, including sleeve pipe (2) and oil pipe (1), its characterized in that is connected with screen pipe (15) in oil pipe (1) bottom, screen pipe (15) lower extreme is connected with plug (16), be connected with the profile control ware that has anti-flow back and tell runner passageway (9) in oil pipe (1) middle part, be connected with the well liquid check valve in oil pipe (1) sub-unit, oil pipe (1) inner wall has wear-resisting polyethylene inside lining or has the anticorrosive anti-scaling coating of tungsten alloy that oozes of plating, anti-flow back and tell runner passageway (9) are the oval passageway that the diameter is greater than 30 mm.

2. The general polymer injection well string according to claim 1, characterized in that the outer wall of the oil pipe (1) is provided with a packer (6).

3. The polymer injection well string according to claim 1, wherein the oil pipe and the profile control unit, the oil pipe and the well fluid check valve, the oil pipe and the screen pipe (15), and the screen pipe (15) and the plug (16) are fixed by thread connection.

4. The polymer injection well string according to claim 2, wherein the packer (6) is fixed to the tubing (1) by a threaded connection.

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