CN115977589A - Four-section type sand sealing and filtering sieve tube - Google Patents

Abstract

The invention relates to a four-section type sand sealing and filtering sieve tube. The problem of current oil well fracturing back sand cause the sand card, bury sand control screen pipe and oil-well pump to cause the inefficacy of oil-well pump lift is mainly solved. The method is characterized in that: the bottom of the upper sieve tube (1) is connected with a middle sieve tube (2), the bottom of the middle sieve tube (2) is connected with a packer (3), and the bottom of the packer (3) is connected with a lower sieve tube (4); a plurality of ceramic filter element assemblies (104) are arranged inside the upper end sieve tube (1); the packer (3) comprises a packer core pipe (302), the outer parts of two ends of the core pipe (302) are respectively connected with an upper guide shoe (303) and a rubber cylinder lower pressing cap (305), and a rubber cylinder (304) is arranged between the upper guide shoe (303) and the rubber cylinder lower pressing cap (305). This four-section type sand-sealing sand-filtering screen pipe can filter fracturing sand and silt that produce after the fracturing, avoids returning the sand to bury sand-filtering screen pipe and oil-well pump, guarantees the normal operating of oil-well pump.

Description

Four-section type sand sealing and filtering sieve tube

Technical Field

The invention relates to the field of oil fields, in particular to a four-section type sand sealing and filtering screen pipe.

Background

Oil well fracturing is one of the important measures for increasing the yield of an oil field, and generally has the phenomenon of sand return after the oil well is put into operation or production is recovered after fracturing, and fracturing sand flows into a shaft from a stratum along with oil. In order to prevent fracturing sand from entering an oil well pump to cause sand blocking and affecting the lifting effect of the oil pumping unit, the fracturing sand is filtered by adopting a mode of connecting a sand control screen pipe under the oil well pump at present, the oil well pump is guaranteed not to be affected by the fracturing sand, and the oil well pump can run normally and stably.

However, with the development of oil fields, a large-scale fracturing mode is often adopted for the development of compact oil, the injection amount of fracturing sand is greatly increased, and the phenomenon of serious sand return frequently occurs after the production of a fracturing well. The fracturing sand returns into a shaft from the stratum, so that not only can the silt component in the fracturing sand be filtered by the sand control screen pipe to cause the problem of sand blocking, but also the fracturing sand returns to bury the sand control screen pipe and the oil well pump to cause the complete failure of the oil well pump during lifting, and meanwhile, the working fluid level of the oil well rises, and no matter is sampled by the oil well pump. During operation treatment, the pipe column is clamped by fracturing sand, the conventional operation cannot be lifted or the pipe column falls off, and the overhaul treatment is needed, so that the operation cost of the oil well is increased.

The prior sand control process after oil well fracturing mainly applies a sand control screen pipe, but only filters fracturing sand in oil liquid, does not filter silt, and cannot solve the problem of lifting failure of an oil well pump caused by the phenomena that the sand return buries the sand control screen pipe and the oil well pump after fracturing.

Disclosure of Invention

In order to overcome the defect that lifting failure of an oil well pump is caused by sand blocking and burying of a sand control screen pipe and the oil well pump due to sand return after fracturing of the existing oil well, the invention provides the four-section sand-sealing sand-filtering screen pipe and the sand control process after fracturing of the oil well.

The technical scheme of the invention is as follows: a four-section sand sealing and sand filtering sieve tube comprises an upper sieve tube and a lower sieve tube, wherein the bottom of the upper sieve tube is connected with a middle sieve tube, the bottom of the middle sieve tube is connected with a packer, and the bottom of the packer is connected with the lower sieve tube; and a plurality of ceramic filter element assemblies are arranged inside the upper sieve tube.

The packer comprises a packer core pipe, the outer parts of two ends of the core pipe are respectively connected with an upper guide shoe and a rubber cylinder lower pressing cap, and a rubber cylinder is arranged between the upper guide shoe and the rubber cylinder lower pressing cap.

The ceramic filter element assembly comprises a filter element outer shell and a filter element inner shell, and a ceramic filter element is arranged between the filter element outer shell and the filter element inner shell; the filter element outer shell is provided with a filter element outer shell liquid inlet gap, and the filter element inner shell is provided with a filter element inner shell liquid outlet gap.

The liquid inlet gap of the outer filter element shell is positioned above the liquid outlet gap of the inner filter element shell.

The filter element inner shell is conical, the liquid outlet gap of the filter element inner shell is positioned at one end with the large diameter of the filter element inner shell, and the liquid inlet gap of the filter element outer shell corresponds to one end with the small diameter of the filter element inner shell.

The middle screen pipe comprises an inner core pipe, an outer filter cylinder is arranged outside the inner core pipe, a liquid outlet hole of an inner cylinder of the middle screen pipe is formed in the inner core pipe, and a liquid outlet gap of an outer cylinder of the middle screen pipe is formed in the outer filter cylinder.

The invention has the following beneficial effects: (1) The four-section sand sealing and filtering screen pipe not only has the sand control effect of other sand control pipe columns, but also has the effects of sealing and returning fracturing sand into a well barrel and filtering sand powder components in petroleum, and the phenomenon that other sand control technologies are buried by the fracturing sand returned from the stratum to cause the failure of an oil well pump can not be caused. (2) The packer in the four-section type sand-sealing and sand-filtering sieve tube has the functions of plugging the annular space of the oil sleeve and preventing fracturing sand returned from the stratum from moving upwards to bury the sieve tube and the oil-well pump. (3) The lower end sieve tube and the middle sieve tube part in the four-section sand-sealing and sand-filtering sieve tube can filter fracturing sand carried in petroleum, and the petroleum forms a stable working fluid level above the packer through the packer, so that the normal production of an oil well pump is ensured. The lower sieve tube is not afraid of being buried by fracturing sand, and can filter the fracturing sand carried in petroleum; the packer stops the fracturing sand below the rubber sleeve, so that the petroleum moves upwards from the central pipe to the middle-end sieve tube, and the fracturing sand is prevented from moving upwards to bury the middle-end sieve tube, the upper-end sieve tube and the oil well pump; the middle section screen pipe can flow oil to the oil jacket annular space from the inner channel, the oil flow direction of the middle section screen pipe is opposite to the oil flow direction in the conventional sand control screen pipe, the effect of communicating the upper oil jacket annular space and the lower oil jacket annular space of the rubber sleeve is mainly played, a stable working fluid level is formed on the rubber sleeve of the packer, and the pumping efficiency of the oil well pump is guaranteed. (4) The upper end screen pipe in the four-section sand-sealing and sand-filtering screen pipe can filter out only a very small amount of silt in oil, and avoids the oil well pump from generating sand blocking. And a multistage ceramic filter element assembly is arranged in the upper sieve tube, and each stage of ceramic filter element assembly can filter petroleum in three layers. The structure of the ceramic filter element assembly has three core innovation points: firstly, a ceramic filter element is used for filtering only a very small amount of silt in petroleum; the oil enters the ceramic filter assembly from the liquid inlet gap of the ceramic filter core outer shell of the sieve tube at the upper end, passes through the ceramic filter core and then enters the liquid inlet channel of the oil well pump from the liquid outlet gap of the ceramic filter core inner shell of the sieve tube at the upper end; the third is the design of the interior cone cylinder of ceramic filter core and filter core inner shell, the setting of cooperation upper end screen pipe ceramic filter core shell feed liquor gap and upper end screen pipe ceramic filter core inner shell play liquid gap, make the oil flow velocity increase suddenly when flowing through filter core inner shell top, pressure reduces suddenly when getting into the last level ceramic filter core assembly, such effect can drive the flow of oil in ceramic filter core assembly, play with higher speed to the effect of upper end screen pipe ceramic filter core inner shell play liquid gap suction and periodic impact, and then prevent that ceramic filter core from blockking up. (5) This four-section type seals sand screen pipe and returns the fracturing sand shutoff in the pit shaft in with the stratum in the certain limit in perforation interval upper portion, fluid can pass through the shutoff interval and form stable liquid working level in the sky of shutoff interval upper portion oil lantern ring, and the silt sand composition that fluid wherein carried before getting into the oil-well pump is filtered completely, guarantees that the oil-well pump is normal, steady production, can not appear the problem of sand burying, sand card.

Drawings

FIG. 1 is an external view of the present invention;

FIG. 2 is a schematic structural view of the present invention;

FIG. 3 is a schematic structural view of a packer;

FIG. 4 is a schematic illustration of a mid-screen configuration;

FIG. 5 is a schematic view of an upper screen construction;

fig. 6 is a schematic diagram of a ceramic filter cartridge assembly.

In the figure, A-a liquid inlet hole of an outer cylinder of an upper screen pipe, B-a liquid inlet hole of a filter element outer shell, C-a liquid outlet hole of an inner shell of a filter element, D-an annular space of an oil jacket, E-a liquid outlet hole of an inner cylinder of an intermediate screen pipe, F-a liquid outlet hole of an outer cylinder of an intermediate screen pipe, G-an oil passage in a packer, H-an oil passage in an inner screen pipe of a lower end, I-an oil inlet hole of an inner screen pipe, J-well oil in a well bore, K-an oil inlet passage of an oil well pump, 1-an upper screen pipe, 2-an intermediate screen pipe, 3-a packer, 4-a lower screen pipe, 5-a plug, 101-a pipe coupling, 102-an upper coupling, 103-an outer cylinder, 104-a ceramic filter element assembly, 105-a lower coupling, 201-an inner joint of an intermediate screen pipe, 202-an inner core pipe, 203-an outer filter cylinder, 301-an inner joint of a packer, 302-a core pipe, 303-an upper guide shoe, 304-a rubber cylinder, 305-a rubber cylinder lower pressure cap, 601-a housing upper cover, 602-an outer shell, 603-a ceramic filter element, 604-a ceramic filter element inner shell, and a housing lower cover 605.

Detailed Description

The invention will be further described with reference to the accompanying drawings in which:

as shown in figures 1 to 6, the four-section sand sealing and filtering sieve tube comprises an upper sieve tube 1 and a lower sieve tube 4, wherein the bottom of the upper sieve tube 1 is connected with a middle sieve tube 2, the bottom of the middle sieve tube 2 is connected with a packer 3, the bottom of the packer 3 is connected with the lower sieve tube 4, and the bottom of the lower sieve tube 4 is connected with a plug 5. The upper end screen 1 comprises an upper joint 102 and a lower joint 105, wherein the upper end of the upper joint 102 is connected with an upper oil pipe through a pipe coupling 101, and the lower joint 105 is a solid joint. An outer cylinder 103 is connected between the upper joint 102 and the lower joint 105, and a plurality of upper screen pipe outer cylinder liquid inlet holes A are formed in the outer cylinder 103. A plurality of ceramic filter element assemblies 104 are arranged in the outer cylinder 103, the ceramic filter element assemblies 104 are limited in the outer cylinder by the upper joint 102 and the lower joint 105, and the two adjacent ceramic filter element assemblies 104 are in compression joint. The ceramic filter element assembly 104 includes a filter element outer shell 602 and a filter element inner shell 604, a ceramic filter element 603 is disposed between the outer shell and the inner shell, and both ends of the filter element outer shell 602 and the filter element inner shell 604 are respectively connected to a shell upper cover 601 and a shell lower cover 605, so as to seal the ceramic filter element 603 between the inner and outer shells. The inner filter element housing 604 is conical, with a small inner diameter at the upper end and a large inner diameter at the lower end. It has filter core outer shell feed liquor gap B to open on the filter core outer shell 602, and it has filter core inner shell to go out liquid gap C to open on the filter core inner shell 604, and filter core outer shell feed liquor gap B is located the filter core inner shell and goes out liquid gap C's top, and filter core inner shell goes out liquid gap C promptly and is located filter core inner shell 604 major diameter one end, and filter core outer shell feed liquor gap B corresponds with filter core inner shell 604 minor diameter one end.

The middle screen pipe 2 comprises an inner core pipe 202, the upper end of the inner core pipe 202 is connected with a lower joint 105 on the upper screen pipe 1 through an inner joint 201 of the middle screen pipe, an outer filter cartridge 203 is arranged outside the inner core pipe 202, a middle screen pipe inner cylinder liquid outlet hole E is formed in the inner core pipe 202, and a middle screen pipe outer cylinder liquid outlet gap F is formed in the outer filter cartridge 203. And the side wall of the lower screen pipe 4 is provided with a lower screen pipe liquid inlet gap I.

The packer 3 is positioned on the lower part of the middle screen pipe 2 and the upper part of the lower screen pipe 4 and comprises an inner joint 301 and a packer core pipe 302 of the packer, the upper part of the inner joint 301 is connected on the lower thread of the inner core pipe 202 in the middle screen pipe 2 through a screw thread, the lower part of the inner joint is connected with the upper thread of the packer core pipe 302, and the lower part of the packer core pipe 302 is connected with the top thread of the lower screen pipe 4. The outer part of the packer core pipe 302 is connected with an upper guide shoe 303 and a rubber sleeve lower pressing cap 305 through threads, and a rubber sleeve 304 is sleeved between the upper guide shoe 303 and the rubber sleeve lower pressing cap 305. The main function of the packing rubber cylinder 3 is to pack the fracturing sand in the oil jacket space D below the rubber cylinder 304.

The working principle of the four-section type sand sealing and filtering sieve tube is as follows: when the fracturing pump-down is carried out after the oil well fracturing is finished, the four-section sand sealing and filtering sieve tube is connected to the lower part of the oil well pump, and then the pump-down operation is carried out; after the operation is finished and the normal production of an oil well is recovered, oil J in a shaft is blocked by a rubber sleeve 304 of a packer 3 in an oil sleeve annular space, but can enter a four-section sand sealing and filtering screen pipe through an inlet gap I in a lower end screen pipe, fracturing sand carried in the oil is blocked outside a lower end screen pipe 4, the oil moves upwards along an oil channel H in the lower end screen pipe, reaches a middle screen pipe 2 through an oil channel G in the sealing rubber sleeve, is upwards blocked by a lower connector 105, flows into an oil sleeve annular space D at the position above the rubber sleeve 304 through an outlet hole E in a middle screen pipe inner cylinder and an outlet gap F in a middle screen pipe outer cylinder, and further forms a stable dynamic liquid level to ensure the pumping effect of an oil well pump. In the process, oil enters the ceramic filter element 603 through the upper end screen pipe outer cylinder liquid inlet hole A and the filter element outer shell liquid inlet gap B in the oil sleeve annular space D and continuously moves upwards, and enters the oil well pump liquid inlet channel K through the filter element inner shell liquid outlet gap C, the oil is filtered for five times, the first filtering is to filter out the fracturing sand carried in the oil at the lower end screen pipe 4, but the oil still contains little superfine sand, the second filtering is at the middle screen pipe 2, the third filtering to the fifth filtering are at the upper end screen pipe 1, little superfine sand carried in the oil is filtered out by the filter element outer shell liquid inlet gap B, the ceramic filter element 603 and the filter element inner shell liquid outlet gap C, and the oil in the oil well pump liquid inlet channel K does not contain the fracturing sand any more. If the oil well needs to be operated again for other reasons, the pulling-out operation is the same as the conventional operation, and no working procedure is added.

Claims (5)

1. The utility model provides a four-section type sand-sealing sand-filtering sieve tube, includes upper end sieve tube (1), lower extreme sieve tube (4), its characterized in that: the bottom of the upper sieve tube (1) is connected with a middle sieve tube (2), the bottom of the middle sieve tube (2) is connected with a packer (3), and the bottom of the packer (3) is connected with a lower sieve tube (4); a plurality of ceramic filter element assemblies (104) are arranged inside the upper end sieve tube (1);

the packer (3) comprises a packer core pipe (302), the outer parts of two ends of the core pipe (302) are respectively connected with an upper guide shoe (303) and a rubber cylinder lower pressing cap (305), and a rubber cylinder (304) is arranged between the upper guide shoe (303) and the rubber cylinder lower pressing cap (305).

2. The four-segment sand-sealing sand-filtering screen pipe according to claim 1, wherein: the ceramic filter element assembly (104) comprises a filter element outer shell (602) and a filter element inner shell (604), and a ceramic filter element (603) is arranged between the filter element outer shell and the filter element inner shell; the filter element outer shell (602) is provided with a filter element outer shell liquid inlet gap (B), and the filter element inner shell (604) is provided with a filter element inner shell liquid outlet gap (C).

3. The four-segment sand-sealing sand-filtering screen pipe according to claim 2, wherein: the filter element outer shell liquid inlet gap (B) is positioned above the filter element inner shell liquid outlet gap (C).

4. The four-segment sand-sealing sand-filtering screen pipe according to claim 3, wherein: the filter element inner shell (604) is conical, the liquid outlet gap (C) of the filter element inner shell is positioned at one end, with the large diameter, of the filter element inner shell (604), and the liquid inlet gap (B) of the filter element outer shell corresponds to one end, with the small diameter, of the filter element inner shell (604).

5. The four-segment sand-sealing sand-filtering screen pipe according to claim 4, wherein: the middle screen pipe (2) comprises an inner core pipe (202), an outer filter cylinder (203) is arranged outside the inner core pipe (202), a middle screen pipe inner cylinder liquid outlet hole (E) is formed in the inner core pipe (202), and a middle screen pipe outer cylinder liquid outlet gap (F) is formed in the outer filter cylinder (203).

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