A device and method for perforating steam injection in heavy oil horizontal wells

Abstract

The present invention provides a perforating steam injection device for heavy oil horizontal wells. The device comprises a support mechanism and a sandblasting perforating string mechanism. The support mechanism comprises oil layer casing, a screen, and a screen hanger. The screen hanger is installed within the oil layer casing, and the screen is mounted on the screen hanger and communicates with the oil layer casing. The sandblasting perforating string mechanism is used to perforate the oil layer and inject steam into the perforated channels. The sandblasting perforating string mechanism is placed in the wellbore formed between the oil layer casing and the screen. The present invention improves oil production in ultra-heavy oil reservoirs.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy oil thermal mining, and in particular relates to a heavy oil horizontal well perforation steam injection device and method. Background Art

[0002] Steam Assisted Gravity Drainage (SAGD) is a widely used commercial method for the development of ultra-heavy oil reservoirs, with large-scale applications in Canada and Xinjiang oilfields in China. However, as the scale of development continues to expand, the physical properties of the ultra-heavy oil reservoirs being mobilized have deteriorated. Reservoir permeability is relatively low, heterogeneity is increasing, and numerous interlayers (interlayers, where the reservoir is not entirely composed of oil sands but contains some low-permeability mudstone layers) have developed. This results in the steam chamber in the SAGD dual-horizontal well group expanding very slowly (the steam chamber refers to the pore volume vacated by the crude oil after steam is injected into the horizontal injection well, reducing its viscosity. The crude oil and steam condensate then flow under gravity into the production horizontal well below for production. As steam continues to be injected, the steam chamber continues to expand outward, and the crude oil at the edge of the steam chamber is continuously heated and produced). This results in extremely slow expansion, resulting in extremely low oil production and seriously affecting development efficiency. Currently, the steam chamber development is promoted by regulating the parameters of steam injection horizontal wells and production horizontal wells, but there are many steam channeling wells, the effect is not obvious, and there are no effective process measures.

[0003] Therefore, it is necessary to design a heavy oil horizontal well perforation steam injection device and method to solve the above technical problems. Summary of the Invention

[0004] In view of the above problems, the present invention provides a heavy oil horizontal well perforation steam injection device, which includes a support mechanism and a sandblasting perforation string mechanism, wherein:

[0005] The supporting mechanism includes an oil layer casing, a screen pipe and a screen pipe hanger, wherein the screen pipe hanger is installed inside the oil layer casing, and the screen pipe is installed on the screen pipe hanger and communicates with the oil layer casing;

[0006] The sandblasting perforating string mechanism is used to shoot out oil layer holes and inject steam into the ejected holes, wherein the sandblasting perforating string mechanism is placed in a wellbore formed between the oil layer casing and the screen pipe.

[0007] Furthermore, the sandblasting perforating string mechanism includes an insulated oil pipe, a sandblasting perforating assembly, a reverse circulation valve, a perforating nipple and a guide shoe, wherein:

[0008] The heat-insulated oil pipe can be inserted into the oil layer casing, and the sandblasting perforating assembly, reverse circulation valve, perforating nipple and guide shoe can all be inserted into the screen pipe;

[0009] The sandblasting and perforating assembly is connected to the heat-insulating oil pipe, the reverse circulation valve is connected to the sandblasting and perforating assembly, the perforating nipple is connected to the reverse circulation valve, and the guide shoe is connected to the perforating nipple.

[0010] Furthermore, the sandblasting perforating assembly includes a centralizer, a diverter, an ejector and two oil pipes, wherein:

[0011] The steering gear is connected to the heat-insulating oil pipe through one of the oil pipes, the ejector is connected to the steering gear through another oil pipe, the reverse circulation valve is connected to the ejector, and the centralizer is sleeved on one of the oil pipes.

[0012] Furthermore, the sandblasting perforating string mechanism also includes a pipe connector, wherein:

[0013] The pipe connector can be inserted into the oil layer casing, and the sandblasting perforating assembly is connected to the heat-insulating oil pipe through the pipe connector.

[0014] Furthermore, the pipe connector includes a conversion joint and a hand-dropping tool, wherein:

[0015] The conversion joint is connected to the hand-releasing tool, the heat-insulating oil pipe is connected to the conversion joint, and the sandblasting and perforating assembly oil pipe is connected to the hand-releasing tool.

[0016] Furthermore, the device also includes a short oil pipe, wherein:

[0017] One end portion of the short oil pipe can be inserted into the oil layer casing and can be communicated with the interior of the screen pipe.

[0018] In another aspect, the present invention provides a method for perforating and injecting steam into a heavy oil horizontal well, the method comprising:

[0019] A support mechanism is run into a steam injection horizontal well, wherein the support mechanism includes an oil layer casing, a screen pipe, and a screen pipe hanger, the screen pipe hanger is installed inside the oil layer casing, and the screen pipe is installed on the screen pipe hanger and communicates with the oil layer casing;

[0020] A sandblasting perforating string mechanism is lowered into the wellbore formed between the oil layer casing and the screen pipe;

[0021] Use sandblasting perforating string mechanism to shoot out the oil layer through the hole;

[0022] A sandblasting perforating string mechanism is used to inject steam into the ejected holes.

[0023] Furthermore, the sandblasting perforating string mechanism includes an insulated oil pipe, a sandblasting perforating assembly, a reverse circulation valve, a perforating nipple and a guide shoe, wherein:

[0024] The heat-insulated oil pipe is located in the oil layer casing, and the sandblasting perforating assembly, reverse circulation valve, perforating nipple and guide shoe are all located in the screen pipe;

[0025] The sandblasting and perforating assembly is connected to the heat-insulating oil pipe, the reverse circulation valve is connected to the sandblasting and perforating assembly, the perforating nipple is connected to the reverse circulation valve, and the guide shoe is connected to the perforating nipple.

[0026] Furthermore, the sandblasting perforating assembly includes an oil pipe, a diverter and an injector, wherein:

[0027] The oil pipe is connected to the heat-insulating oil pipe, the steering gear is connected to the oil pipe, the injector is connected to the steering gear, and the reverse circulation valve is connected to the injector.

[0028] Furthermore, before lowering the support mechanism into the steam injection horizontal well, the following steps are also included:

[0029] Drilling steam injection horizontal wells and production horizontal wells with preset horizontal section lengths in underground oil layers;

[0030] Furthermore, the steps for lowering the support mechanism into the steam injection horizontal well are as follows:

[0031] The oil layer casing is lowered into the heel of the horizontal section of the steam injection horizontal well, and cement is injected between the oil layer casing and the borehole for cementing. Then, a screen pipe is lowered into the heel tip of the horizontal section of the steam injection horizontal well.

[0032] Further,

[0033] The steps for running the sandblasting perforating string mechanism into the wellbore formed between the oil layer casing and the screen are as follows:

[0034] The entire sandblasting perforating string mechanism is lowered into the wellbore formed between the oil layer casing and the screen pipe, and the guide shoe in the sandblasting perforating string mechanism is lowered to the toe of the horizontal section of the steam injection horizontal well.

[0035] Furthermore, the steps of using the sandblasting perforating string mechanism to perforate the oil layer are as follows:

[0036] Put soluble balls into the insulated oil pipe and close the reverse circulation valve;

[0037] Inject sand-carrying fluid into the insulated oil pipe until the sand from the injector penetrates the screen to form channels on the oil layer.

[0038] Further,

[0039] The steps for injecting steam into the perforated channel using a sandblasting perforating string mechanism are as follows:

[0040] After the holes are formed on the oil layer, steam is injected into the insulated oil pipe so that the steam is injected into the holes through the ejector and the perforated nipple.

[0041] The present invention provides a perforation steam injection device and method for heavy oil horizontal wells, which can overcome the problems of small and uneven steam injection impact range, slow and uneven steam chamber development, low production and poor efficiency in current low-permeability, highly heterogeneous and ultra-heavy oil reservoirs.

[0042] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 A structural schematic diagram of a heavy oil horizontal well perforation steam injection device according to an embodiment of the present invention is shown.

[0045] Figure 2 The embodiment according to the present invention is shown Figure 1 Schematic diagram of the structure of the injector with the nozzle facing downward.

[0046] In the figure, 1-oil layer; 2-horizontal steam injection well; 3-horizontal production well; 4-oil layer casing; 5-screen hanger; 6-screen; 7-insulated oil pipe; 8-conversion joint; 9-hand-release tool; 10-centralizer; 11-diverter; 12-injector; 13-oil pipe; 14-reverse circulation valve; 15-perforating nipple; 16-guide shoe; 17-channel; 18-short oil pipe, 111, semicircular block, 112, long strip block. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0048] like Figure 1 As shown, the present invention provides a heavy oil horizontal well perforation steam injection device, the device includes a support mechanism and a sandblasting perforation string mechanism, wherein,

[0049] The support mechanism includes an oil layer casing 4, a screen 6, and a screen hanger 5. The screen hanger 5 is installed inside the oil layer casing 4 and is sealed and anchored between the oil layer casing 4. The screen 6 is installed on the screen hanger 5 and communicates with the oil layer casing 4. The outer diameter of the oil layer casing 4 is preferably 244.5 mm or 273 mm, and the outer diameter of the screen 6 is preferably 168.3 mm or 177.8 mm.

[0050] The sandblasting perforating string mechanism is used to eject the oil layer into the hole 17 and inject steam into the ejected hole 17 , wherein the sandblasting perforating string mechanism is placed in the wellbore formed between the oil layer casing 4 and the screen pipe 6 .

[0051] The sandblasting perforating string mechanism is described in detail below:

[0052] The sandblasting perforating string mechanism includes an insulated oil pipe 7, a sandblasting perforating assembly, a reverse circulation valve 14, a perforating nipple 15, a guide shoe 16 and a short oil pipe 18, wherein:

[0053] The insulated oil pipe 7 can be inserted into the oil layer casing 4, and one end of the short oil pipe 18 can also be inserted into the oil layer casing 4; the sandblasting perforating assembly, the reverse circulation valve 14, the perforating short section 15 and the guide shoe 16 can all be inserted into the screen pipe 6. Among them, the insulated oil pipe 7 is a double-layer concentric pipe structure, and the outer layer of the insulated oil pipe 7 and the inner layer of the insulated oil pipe 7 are vacuumed to form thermal insulation protection. The outer diameter of the outer layer of the insulated oil pipe 7 is preferably 114.3mm, and the inner diameter of the inner layer of the insulated oil pipe 7 is preferably 76mm; the outer diameter of the short oil pipe 18 is preferably 60.3mm, and an inner coupling oil pipe is used (the short oil pipe 18 uses an inner coupling oil pipe, which is a type of oil pipe. The outer diameter of the coupling of this type of oil pipe is the same as the outer diameter of the oil pipe, and the inner diameter is smaller than the inner diameter of the oil pipe. In this way, the overall outer diameter of the oil pipe string formed after connection is consistent, and there is no protruding part, which is convenient for oil The pipe is lifted and lowered, especially in the horizontal section where the friction is small), and the lowering position is preferably to the screen hanger 5 before entering the horizontal section, ensuring that the short oil pipe 18 can pass through the screen hanger 5 smoothly, so that the port at one end of the short oil pipe 18 is located in the horizontal section of the steam injection horizontal well 2 and can be connected with the inside of the screen pipe 6, which has a protective effect on the oil layer casing 4 and prevents the steam from entering the annular space between the oil layer casing 4 and the short oil pipe 18 when the steam is injected through the short oil pipe 18 if the short oil pipe 18 is placed on the hanger 5. Under long-term high temperature conditions, the oil layer casing 4 is at risk of deformation or damage to the cementing cement.

[0054] In this embodiment, the number of sandblasting and perforating assemblies can be 1-10. When there is only one sandblasting and perforating assembly, the sandblasting and perforating assembly is connected to the insulated oil pipe 7, the reverse circulation valve 14 is connected to the sandblasting and perforating assembly, the perforating sub 15 is connected to the reverse circulation valve 14, and the guide shoe 16 is connected to the perforating sub 15. Furthermore, the sandblasting and perforating assembly includes a centralizer 10, a diverter 11, an ejector 12, and two oil pipes 13. The diverter 11 is connected to the insulated oil pipe 7 via one of the oil pipes 13, the ejector 12 is connected to the diverter 11 via the other oil pipe 13, and the reverse circulation valve 14 is connected to the ejector 12. The centralizer 10 is sleeved on one of the oil pipes 13 (the centralizer 10 positions the sandblasting and perforating string mechanism in the center of the screen pipe 6, reducing frictional resistance between the sandblasting and perforating string mechanism and the inner wall of the screen pipe 6).

[0055] When there are more than one sandblasting and perforating assembly, for example, three, the three sandblasting and perforating assemblies are connected sequentially, with the first and last two sandblasting and perforating assemblies respectively connected to the insulated oil pipe 7 and the reverse circulation valve 14. Furthermore, each sandblasting and perforating assembly includes a centralizer 10, a diverter 11, an ejector 12, and two oil pipes 13. The diverter 11 in each sandblasting and perforating group is connected to the insulated oil pipe 7 via one of the oil pipes 13, and the ejector 12 is connected to the diverter 11 via another oil pipe 13. The centralizer 10 is sleeved on one of the oil pipes 13, with the oil pipe 13 near the insulated oil pipe 7 connected to the insulated oil pipe 7, and the oil pipe 13 near the reverse circulation valve 14 is connected to the reverse circulation valve 14.

[0056] In this embodiment, the inner diameter of the inner layer of the insulated oil pipe 7 is preferably 76 mm, and the outer diameter of the oil pipe 13 is preferably 73 mm, ensuring that the inner diameters of the insulated oil pipe 7 and the oil pipe 13 are sufficiently large. The oil pipe 13 uses an internal coupling to facilitate passage through the screen hanger 5. The oil pipe 13 has low resistance when lowered into the horizontal section of the relatively long steam injection horizontal well 2 (300-800 m long), and can be lowered to the toe of the horizontal section of the steam injection horizontal well 2.

[0057] The diverter 11 can make the nozzle of the ejector 12 face the preset direction for sandblasting (such as Figure 2 As shown, the diverter 11 includes a semicircular block 111 and a long strip 112, one end of the long strip 112 is connected to the plane of the semicircular block 111, and the other end of the long strip 112 is an arc surface. When the diverter 11 is designed, its center of gravity is not at the center of the diameter, but is biased to one side. After being lowered into the horizontal section, the connected injector 12 is driven to rotate together under the action of gravity until the center of gravity is at the bottom; for example, if it is necessary to make the nozzle of the injector 12 face downward, the nozzle direction of the injector 12 is installed on the side with the same center of gravity as the diverter 11, so that under the action of the gravity of the diverter 11, when the diverter 11 is lowered into the screen pipe 6, the nozzle of the corresponding injector 12 faces downward, forming a Figure 2status shown);

[0058] The reverse circulation valve 14 is a one-way valve. Fluid can be injected into the screen pipe 6 from the insulated tubing 7. After a soluble ball is dropped into the insulated tubing 7, the soluble ball rolls to the reverse circulation valve 14 and closes the reverse circulation valve 14, preventing the fluid from entering the perforated nipple 15 through the reverse circulation valve 14. As a result, the fluid can enter the casing annulus (the casing annulus is the space formed between the oil layer casing 4, the insulated tubing 7, and the short tubing 18) from the screen pipe 6, and thus return to the steam injection horizontal well 2.

[0059] The guide shoe 16 is used to guide the sandblasting perforating string mechanism to smoothly descend into the depth of the horizontal section of the steam injection horizontal well 2.

[0060] In this embodiment, the sandblasting and perforating string mechanism also includes a pipe connector, wherein the pipe connector can be inserted into the oil layer casing 4, and the sandblasting and perforating assembly is connected to the insulated oil pipe 7 via the pipe connector. Furthermore, the pipe connector includes a conversion joint 8 and a release tool 9, wherein the conversion joint 8 is connected to the release tool 9, the insulated oil pipe 7 is connected to the conversion joint 8, and the sandblasting and perforating assembly oil pipe 13 is connected to the release tool 9.

[0061] In this embodiment, all steps in the entire sandblasting perforating string mechanism lowered into the horizontal section are chamfered (for example, the connecting end of the oil pipe 13 connected to the diverter 11 is chamfered, the connecting end of the oil pipe 12 connected to the injector 12 is chamfered, etc.), so as to prevent the sandblasting perforating string mechanism from being unable to pass through the screen hanger 5.

[0062] In addition, the present invention also provides a method for perforating and injecting steam into a heavy oil horizontal well, which can utilize the above-mentioned device. Specifically, the method includes:

[0063] Step S1: lowering the entire support mechanism into the steam injection horizontal well;

[0064] Step S2: lowering the entire sandblasting perforating string mechanism into the wellbore formed between the oil layer casing 4 and the screen tube 6;

[0065] Step S3, using a sandblasting perforating string mechanism to perforate the oil layer into a hole 17;

[0066] Step S4: Use the sandblasting perforating string mechanism to inject steam into the ejected duct 17 .

[0067] Before lowering the support mechanism into the steam injection horizontal well, the following step S0 is also included:

[0068] A steam injection horizontal well 2 and a production horizontal well 3 with preset horizontal section lengths are drilled in the underground oil layer, wherein the horizontal section of the steam injection horizontal well 2 is 1-2 meters away from the bottom of the oil layer 1, the horizontal section of the steam injection horizontal well 2 is parallel to the horizontal section of the production horizontal well 3, and the vertical spacing between the two is 5 meters. The lengths of the horizontal sections of the steam injection horizontal well 2 and the production horizontal well 3 are both greater than 300 meters, preferably 400-500 meters.

[0069] Step S1 is specifically as follows:

[0070] After the steam injection horizontal well 2 and the production horizontal well 3 are completed, a screen pipe 6 is lowered into the toe of the horizontal section of the steam injection horizontal well 2, and the oil layer casing 4 and the screen pipe 6 (the oil layer casing 4 and the screen pipe 6 are connected by a screen pipe hanger 5) are lowered into the heel of the horizontal section of the steam injection horizontal well 2, and cement is injected between the oil layer casing 4 and the borehole for cementing.

[0071] Step S2 is specifically as follows:

[0072] The entire sandblasting perforating string mechanism is lowered into the wellbore formed between the oil layer casing 4 and the screen tube 6, and the guide shoe 16 in the sandblasting perforating string mechanism is lowered to the toe of the horizontal section of the steam injection horizontal well 2. That is, the guide shoe 16 in the sandblasting perforating string mechanism is lowered to the toe of the horizontal section of the steam injection horizontal well 2;

[0073] Run the short oil pipe 18 so that the end of the short oil pipe 18 passes through the screen hanger 5 and is located in the screen 6;

[0074] It should be noted that when the sandblasting perforating string mechanism is lowered, the working position of the ejector 12 should avoid the screen pipe coupling (the screen pipe 6 is multi-sectioned, and a screen pipe coupling is passed between every two sections of the screen pipe 6); the corresponding position of the ejector 12 is preferably an oil layer 1 with relatively low permeability, developed interlayers, and poorly developed steam chambers.

[0075] Before the sandblasting and perforating operation, the following steps are also included:

[0076] SS11, perform sand flushing and well washing operations to remove sand accumulation in the wellbore formed between the oil layer casing 4 and the screen pipe 6, thereby reducing the resistance to the lowering of the sandblasting perforating string mechanism and the construction risk;

[0077] SS12. Run the well gauge to the end of the horizontal section of the steam injection horizontal well 2 to check whether the screen pipe 6 in the horizontal section of the steam injection horizontal well 2 is deformed to ensure the smooth running of the sandblasting perforating string mechanism.

[0078] Step S3 is as follows:

[0079] Put soluble balls into the insulated oil pipe 7 and close the reverse circulation valve 14;

[0080] Inject sand-carrying fluid into the insulated oil pipe 7 until the ejector 12 blasts sand through the screen pipe 6, so that a pore 17 is formed on the oil layer.

[0081] The ejector 12 is used to perform sandblasting and perforating operations. Based on the Bernoulli principle, sand is added to a liquid (water or guar gum fracturing fluid) to form a sand-carrying fluid. When the sand-carrying fluid passes through the nozzle of the ejector 12, the small outer diameter of the nozzle throttling effect converts the high-pressure sand-carrying fluid into high-speed kinetic energy, forming a high-speed sand-carrying jet, which penetrates the screen 6, connects to the oil layer 1, and forms a channel 17 in the oil layer 1. When the injection velocity of the sand-carrying fluid reaches 200 m / s, multiple ejectors 12 can penetrate the corresponding multiple sections of the screen 6.

[0082] The ejector 12 can be set to blast upward in a directional manner. For the case where the connectivity between the steam injection horizontal well and the production horizontal well in the super-heavy oil reservoir is poor, the ejector 12 can be selected for non-directional sandblasting according to the specific location of the channel to be formed. The specific principle is that the direction of the sandblasting of the ejector 12 should be toward the pre-transformed oil layer.

[0083] After the sand-carrying fluid is injected, the fracturing fluid is injected and circulated to the wellhead of the steam injection horizontal well 2 until no sand is returned. The amount of sand-carrying fluid added is 3-6m 3 ; Construction displacement (fracturing fluid injection speed) is 2-6m 3 / min;

[0084] The medium of the sand-carrying fluid can be water or guar gum fracturing fluid; the proppant of the sand-carrying fluid can be quartz sand or ceramsite; after the sandblasting perforation is completed, the steam injection horizontal well 2 can be fractured or not.

[0085] It should be noted that sandblasting perforation is preferably directed upward; if the connectivity between the steam injection horizontal well 2 and the production horizontal well 3 is poor, non-directional perforation can be preferred based on the specific location of the perforation; the preferred principle is that the perforation direction should be toward the pre-transformed oil layer.

[0086] After the sandblasting and perforating operation, the following steps are also included:

[0087] SS21, inject temporary plugging liquid into the horizontal section through the insulated oil pipe 7,

[0088] The temporary plugging fluid adopts a high-strength gel system that dissolves at high temperatures;

[0089] The calculation formula for the injection volume of temporary plugging fluid is:

[0090]

[0091] Where V is the volume of the injected temporary plugging fluid, in m 3; k is an additional coefficient, which is generally taken as 1.05-1.10 based on experience; D is the outer diameter of the horizontal section of the steam injection horizontal well 2, in m (meter); d is the outer diameter of the screen pipe 6 in the steam injection horizontal well 2, in m (meter); d1 is the outer diameter of the screen pipe 6 in the steam injection horizontal well 2, in m (meter); L is the length of the horizontal section of the steam injection horizontal well 2, in m (meter).

[0092] By temporarily blocking the inside of the screen pipe 6 and the annular space between the screen pipe 6 and the wellbore of the horizontal section of the steam injection horizontal well 2, reverse sand production of the oil layer 1 is avoided, the pores 17 formed in the oil layer 1 are protected, and the sandblasting perforating string mechanism is protected from being buried by sand, thereby providing conditions for steam injection.

[0093] Step S4 is specifically as follows:

[0094] After perforating the oil layer 1 to form the channel 17, steam is injected into the insulated oil pipe 7 and the oil pipe 13 (the steam will melt the soluble ball of the closed reverse circulation valve, thereby allowing the steam to flow out of the perforating sub 15). The steam is injected into the channel 17 through the ejector 12 and the perforating sub 15 and then diffuses into the oil layer 1. Compared with the previous process in which the channel 17 is not formed by perforating, the resistance to steam injection in this process will be greatly reduced, and the steam chamber will expand faster, thereby improving the utilization of the horizontal section of the steam injection horizontal well 2 (that is, perforating the horizontal section of the steam injection horizontal well 2 where the oil layer is not well utilized to improve the steam injectivity, so as to achieve efficient crude oil production in the oil layer corresponding to the horizontal section of the steam injection horizontal well 2).

[0095] In addition, in this embodiment, if sanding or the like occurs in the horizontal section of the steam injection horizontal well 2 when the sandblasting and perforating string mechanism is in operation, the release pin on the release tool 9 can be cut off to lift out the heat-insulating oil pipe 7 in the sandblasting and perforating string mechanism together with the conversion joint 8, while the other parts of the sandblasting and perforating string mechanism are detached and not lifted out, thereby providing working space for the well repair operation.

[0096] The present invention provides a perforating steam injection device and method for a heavy oil horizontal well. A support mechanism and a sandblasting perforating string mechanism are lowered into the steam injection horizontal well 2, and the horizontal section of the steam injection horizontal well 2 is subjected to a first-level multi-cluster hydraulic sandblasting perforation. That is, the screen pipe 6 in the horizontal section of the steam injection horizontal well 2 is perforated in sections to form deep-penetrating large channels 17 in the oil layer 1. Steam is then injected into the oil layer 1 at a fixed point through the sandblasting perforating string mechanism, effectively improving the uniformity of steam injection and the expansion range of the steam chamber in the horizontal section of the steam injection horizontal well 2, and improving the steam chamber development speed, thereby achieving the purpose of increasing production.

[0097] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A perforation steam injection device for heavy oil horizontal wells, characterized in that: The device includes a support mechanism and a sandblasting perforating string mechanism, wherein: The supporting mechanism includes an oil layer casing, a screen pipe and a screen pipe hanger, wherein the screen pipe hanger is installed inside the oil layer casing, and the screen pipe is installed on the screen pipe hanger and communicates with the oil layer casing; The sandblasting perforating string mechanism is used to shoot out holes in the oil layer and inject steam into the ejected holes, wherein the sandblasting perforating string mechanism is placed in the wellbore formed between the oil layer casing and the screen pipe; The sandblasting perforating pipe string mechanism includes an insulated oil pipe, a sandblasting perforating assembly, a reverse circulation valve, a perforating nipple and a guide shoe, wherein: The heat-insulated oil pipe can be inserted into the oil layer casing, and the sandblasting perforating assembly, reverse circulation valve, perforating nipple and guide shoe can all be inserted into the screen pipe; The sandblasting and perforating assembly is connected to the insulated oil pipe, the reverse circulation valve is connected to the sandblasting and perforating assembly, the perforating nipple is connected to the reverse circulation valve, and the guide shoe is connected to the perforating nipple; The steps for using the sandblasting perforating string mechanism to eject the oil layer into the hole are as follows: Put soluble balls into the insulated oil pipe and close the reverse circulation valve; Inject sand-carrying fluid into the insulated oil pipe until the sand blasting by the ejector penetrates the screen pipe to form a channel on the oil layer; The steps for injecting steam into the perforated channel using a sandblasting perforating string mechanism are as follows: After the channel is formed on the oil layer, steam is injected into the insulated oil pipe so that the steam is injected into the channel through the ejector and the perforated nipple; the steam melts the soluble ball of the closed reverse circulation valve, thereby allowing the steam to flow out from the perforated nipple.

2. The heavy oil horizontal well perforation steam injection device according to claim 1, characterized in that: The sandblasting perforating assembly includes a centralizer, a diverter, an ejector and two oil pipes, wherein: The steering gear is connected to the heat-insulating oil pipe through one of the oil pipes, the ejector is connected to the steering gear through another oil pipe, the reverse circulation valve is connected to the ejector, and the centralizer is sleeved on one of the oil pipes.

3. The heavy oil horizontal well perforation steam injection device according to claim 1, characterized in that: The sandblasting perforating pipe string mechanism also includes a pipe connector, wherein: The pipe connector can be inserted into the oil layer casing, and the sandblasting perforating assembly is connected to the heat-insulating oil pipe through the pipe connector.

4. The heavy oil horizontal well perforation steam injection device according to claim 3, characterized in that: The pipe connector includes a conversion joint and a hand-dropping tool, wherein: The conversion joint is connected to the hand-releasing tool, the heat-insulating oil pipe is connected to the conversion joint, and the sandblasting and perforating assembly is connected to the hand-releasing tool.

5. A heavy oil horizontal well perforation steam injection device according to any one of claims 1 to 4, characterized in that: The device also includes a short oil pipe, wherein One end portion of the short oil pipe can be inserted into the oil layer casing and can be communicated with the interior of the screen pipe.

6. A method for perforating and injecting steam into a heavy oil horizontal well, characterized in that: The method comprises: A support mechanism is run into a steam injection horizontal well, wherein the support mechanism includes an oil layer casing, a screen pipe, and a screen pipe hanger, the screen pipe hanger is installed inside the oil layer casing, and the screen pipe is installed on the screen pipe hanger and communicates with the oil layer casing; A sandblasting perforating string mechanism is lowered into the wellbore formed between the oil layer casing and the screen pipe; Use sandblasting perforating string mechanism to shoot out the oil layer through the hole; Use a sandblasting perforating string mechanism to inject steam into the ejected holes; The sandblasting perforating pipe string mechanism includes an insulated oil pipe, a sandblasting perforating assembly, a reverse circulation valve, a perforating nipple and a guide shoe, wherein: The heat-insulated oil pipe is located in the oil layer casing, and the sandblasting perforating assembly, reverse circulation valve, perforating nipple and guide shoe are all located in the screen pipe; The sandblasting and perforating assembly is connected to the insulated oil pipe, the reverse circulation valve is connected to the sandblasting and perforating assembly, the perforating nipple is connected to the reverse circulation valve, and the guide shoe is connected to the perforating nipple; The steps for using the sandblasting perforating string mechanism to eject the oil layer into the hole are as follows: Put soluble balls into the insulated oil pipe and close the reverse circulation valve; Inject sand-carrying fluid into the insulated oil pipe until the sand blasting by the ejector penetrates the screen pipe to form a channel on the oil layer; The steps for injecting steam into the perforated channel using a sandblasting perforating string mechanism are as follows: After the channel is formed on the oil layer, steam is injected into the insulated oil pipe so that the steam is injected into the channel through the ejector and the perforated nipple; the steam melts the soluble ball of the closed reverse circulation valve, thereby allowing the steam to flow out from the perforated nipple.

7. A method for perforating and injecting steam into a heavy oil horizontal well according to claim 6, characterized in that: The sandblasting perforating assembly includes an oil pipe, a diverter and an injector, wherein: The oil pipe is connected to the heat-insulating oil pipe, the steering gear is connected to the oil pipe, the injector is connected to the steering gear, and the reverse circulation valve is connected to the injector.

8. A method for perforating and injecting steam into a heavy oil horizontal well according to claim 6 or 7, characterized in that: Before running the support mechanism into the steam injection horizontal well, the following steps are also included: In the underground oil layer, a steam injection horizontal well and a production horizontal well with a preset horizontal section length are drilled.

9. A method for perforating and injecting steam into a heavy oil horizontal well according to claim 8, characterized in that: The steps for running the support structure in a horizontal steam injection well are as follows: The oil layer casing is lowered into the heel of the horizontal section of the steam injection horizontal well, and cement is injected between the oil layer casing and the borehole for cementing. Then, a screen pipe is lowered into the heel tip of the horizontal section of the steam injection horizontal well.

10. The method for perforating and steam injection in heavy oil horizontal wells according to claim 6, characterized in that: The steps for running the sandblasting perforating string mechanism into the wellbore formed between the oil layer casing and the screen are as follows: The entire sandblasting perforating string mechanism is lowered into the wellbore formed between the oil layer casing and the screen pipe, and the guide shoe in the sandblasting perforating string mechanism is lowered to the toe of the horizontal section of the steam injection horizontal well.

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