Ultra-high pressure hydraulic deep penetration perforating device and method for under- injection wells in low-permeability reservoirs

Abstract

The present disclosure relates to a kind of low permeability oil reservoir reservoir under- injection well with ultra-high pressure hydraulic deep penetration perforating device and method, can realize fixed point, azimuthal perforation, hole depth is 4-5m, hole diameter is 1.2cm, can effectively break through near wellbore pollution zone, increase drainage area, simultaneously, according to different layer, carry out individualized hole distribution, carry out full well effective plugging for under-injection well, reach the purpose of integrated plugging of targeted plugging, deep penetration, separate layer water control, input-output ratio reaches 1:2 or more;The present application process has strong applicability, avoids the shortcomings of conventional acidification, fracturing, plugging measures such as hole repair, also improves the technical height of conventional hydraulic perforation, the efficiency is improved by more than 3 times in applicable depth, super-penetration, super-time effect, can greatly reduce the injection pressure of under-injection well, improve water injection, realize effective plugging, provide technical support for peripheral low permeability reservoir under-injection well plugging.

Description

Technical Field

[0001] This disclosure relates to the field of oilfield production engineering technology, and in particular to an ultra-high pressure hydraulic deep penetration perforation process for under-injected wells in low-permeability sandstone reservoirs. Background Technology

[0002] The statements in this section provide only background information in connection with this disclosure and do not constitute prior art.

[0003] As development time progresses in the low-permeability reservoirs surrounding the Daqing Oilfield, and the injected water contains oil and suspended solids, near-wellbore blockage occurs, leading to a gradual decline in the injection capacity of some water injection wells within the reservoir block and an increase in under-injected wells. Simultaneously, the deteriorating quality of under-injected wells year by year has resulted in a decreasing formation pressure in the block, directly causing an increase in the proportion of low-production wells. This prevents the oil and water wells from achieving injection-production balance, impacting the waterflood development level of the peripheral low-permeability reservoirs. Therefore, it is essential to employ unblocking techniques to restore the injection capacity of water injection wells.

[0004] The main characteristics of blockage in low-permeability oil reservoirs are: complex blockage factors, large blockage radius, and significant differences in the degree of blockage between different layers. Various injection enhancement measures implemented by peripheral oilfields, such as acidizing, fracturing, and perforation, have achieved some results, but are not ideal. Acidizing measures employ a general acidizing technique, failing to treat severely blocked layers, resulting in poor overall injection enhancement, short effective time, and failure to achieve the goal of stratified water control. Fracturing and cracking measures use a one-size-fits-all approach to vertical fractures, providing sufficient unblocking radius, but the layers are interconnected vertically, failing to achieve stratified water control, and incurring high costs. Perforation measures can achieve unblocking at a specific depth as needed, but their capacity is limited. For example, the YD102 perforation bomb used in peripheral areas has a penetration depth of 73cm and a borehole diameter of 10mm; the shallow penetration depth cannot penetrate the compacted contaminated zone (2-4m), and dense perforation is not possible, failing to remove oil layer contamination. Therefore, a convenient and quick targeted depth and deep penetration technology is needed to accurately locate contaminated zones in the formation. The process of using hydraulic sand-carrying for directional deep penetration through a perforation can meet the purpose of precise unblocking.

[0005] A great deal of applied research has been conducted in China on hydraulic deep-penetration perforation technology, but the main focus of the research is on perforation devices and auxiliary measures.

[0006] CN209067179U discloses a hydraulic perforation device, including a cylindrical shell, a stabilizer, a water spray pipe, a feed and receive hydraulic cylinder, and a wedge-shaped moving hydraulic cylinder, but it does not have a sand-carrying device function, and there is no detailed application in terms of application.

[0007] CN116084893B discloses an integrated hydraulic perforation and fluid production device and its usage method for oil and gas wells. This device combines hydraulic sand-jetting perforation and hydraulic jet fluid production technologies, enabling simultaneous sand-addition angle perforation and hydraulic jet fluid production, thereby improving the efficiency of oil testing and production. However, this method uses tubing for delivery, resulting in low jet pressure and a penetration depth of 1.5-2.0m, which cannot completely penetrate the contaminated zone. Furthermore, the jet nozzle strength is insufficient, leading to significant nozzle wear. Only 4-6 perforations are needed per run, requiring two or three repeated trips of tubing string operation to complete the process. Ideal unblocking and injection enhancement measures for under-injected wells in oilfields require targeted unblocking, deep penetration, and stratified water control completed in one operation, along with rapid and convenient reservoir construction. Therefore, this patented technology does not meet the requirements for multi-layer integrated unblocking. In addition, tubing delivery refers to using 2.5-inch tubing to connect and send the perforating equipment downhole. The equipment is then lowered for pre-magnetic positioning and depth adjustment. This process has several problems: First, the construction process involves many steps; second, the tubing diameter is too large, making it difficult to control the amount of sand discharged; third, connecting 100-200 tubing sections requires a long construction time; fourth, the injection power is provided by the wellhead pump truck, resulting in low injection pressure (<30MPa) and unstable output, leading to low initial kinetic energy for sand production and short perforation distance; fifth, the use of two lines (pipes) for construction, i.e., an external positioning cable connected to the tubing, makes it difficult to secure the cable, causing it to become tangled and stuck in the tubing, making the construction extremely difficult.

[0008] In their 2022 article "Application of Adaptive Directional Hydraulic Jetting and Perforation Technology for Coiled Tubing in Tight Oil Horizontal Wells" published in Volume 22, Issue 15 of *Science, Technology and Engineering*, Aibaibu Abulimiti et al. proposed an integrated fracturing process for coiled tubing, adaptive directional jetting and perforation with sand filling, and developed a matching adaptive directional device for horizontal wells. This technology was applied to the fracturing of the Ma1 well in the Mahu tight oil well, achieving good results. This technology is an auxiliary measure for fracturing large horizontal oil wells. It uses tubing for transport, resulting in expensive equipment, a large footprint, and a long construction period. Furthermore, when used for water well enlargement, this technology can lead to problems with single-tube construction. Also, because the coiled tubing can only maintain its depth independently and cannot be magnetically positioned for depth determination, excessive coiled tubing windings on the surface can easily cause sand accumulation and blockage.

[0009] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art. Summary of the Invention

[0010] In view of this, this disclosure provides an ultra-high pressure hydraulic deep penetration perforation device and method for under-injected wells in low-permeability oil reservoirs, which solves the problem that current hydraulic deep penetration perforation technology for under-injected wells cannot achieve multi-layer integrated unblocking because targeted unblocking, deep penetration, and stratified water control cannot be completed in one go, resulting in unsatisfactory treatment effects.

[0011] To achieve the aforementioned objective, in a first aspect, the ultra-high pressure hydraulic deep penetration perforation device for under-injected wells in low-permeability oil reservoirs comprises:

[0012] Supporting equipment and perforation equipment;

[0013] The supporting equipment includes an injection pump, a pressure-resistant hose, and a pressure-resistant nozzle.

[0014] The power of the injection pump is 120-200KW, the internal pressure of the pressure-resistant hose is >100MPa, and the material of the pressure-resistant nozzle is molybdenum-based titanium alloy.

[0015] In this disclosure and possible embodiments, the apparatus further includes:

[0016] The three-wire integrated clamp is equipped with three holes that allow the pressure-resistant hose, steel cable, and cable to pass through respectively.

[0017] In this disclosure and possible embodiments, the supporting equipment further includes a quantitative sand adding mechanism, which includes a quantitative sand feeder connected to a pressurizing device and an ultrasonic monitor. The pressurizing device is used to control the sand adding speed, and the ultrasonic monitor is used to control the sand adding amount. In this disclosure and possible embodiments, the supporting equipment further includes a magnetic depth gauge and a gyroscope, which are used to calibrate the working depth.

[0018] In this disclosure and possible embodiments, the pressure-resistant hose is delivered via a hose reel.

[0019] Secondly, the method for using ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs includes:

[0020] Using the ultra-high pressure hydraulic deep penetration perforation device described in any of the first aspects, the wells in low-permeability oil reservoirs that are under-injected are unblocked and injected.

[0021] In this disclosure and possible embodiments, the perforation equipment is delivered downhole via a pressure-resistant hose.

[0022] In this disclosure and possible embodiments, the pressure-resistant hose, steel cable, and electrical cable are transmitted via a three-wire integrated clamp.

[0023] In this disclosure and possible embodiments, the method includes calculating the locations of each perforation point and the coupling position at the stratigraphic level, and the calculation formula is:

[0024] H-perforation / coupling depth = L-indicated depth + ΔL-natural elongation + (h-sleeve gap - h-way height - h-blowout preventer) + ΔH 前磁误差 ;

[0025] Where: △L natural elongation = H perforation / coupling depth * 0.003;

[0026] H-perforation / coupling depth is the actual well depth of the perforation / coupling;

[0027] The L-display depth is the well depth shown on the control panel;

[0028] △L is the natural elongation length of the steel wire;

[0029] h-set spacing is the basic data;

[0030] h-type height is the basic data;

[0031] h-blower preventer is based on the data;

[0032] △H 前磁误差 These are actual measured data.

[0033] In this disclosure and possible embodiments, the method further includes verifying the calculation results of each perforation point and coupling position at the layer location, the verification method including:

[0034] Lower the steel cable to the lowest perforation point, activate the pre-magnetic positioning calibration depth, find the joint position of the two closest points, and verify the displayed depth and actual depth. If the error is less than 0.01m, it is considered accurate. If the error is greater than 0.01m, the pre-magnetic error correction calculation formula is added.

[0035] The beneficial effects of this invention are as follows:

[0036] The present invention relates to an ultra-high pressure hydraulic deep-penetration perforation device and method for under-injected wells in low-permeability oil reservoirs. This device enables targeted and directional perforation with a depth of 4-5 meters and a borehole diameter of 1.2 cm. It effectively penetrates the near-wellbore contamination zone, increasing the drainage area. Furthermore, it allows for customized perforation layout based on different formations, effectively unblocking the entire under-injected well. This achieves an integrated unblocking process encompassing targeted unblocking, deep penetration, and stratified water control, with an input-output ratio exceeding 1:2. The invention's process is highly adaptable, avoiding the shortcomings of conventional acidizing, fracturing, and perforation repair methods. It also improves upon conventional hydraulic perforation techniques, increasing efficiency by more than three times in terms of applicable depth, ultra-penetration depth, and extended aging time. This significantly reduces injection pressure in under-injected wells, increases injection volume, and achieves effective unblocking, providing technical support for unblocking under-injected wells in peripheral low-permeability reservoirs. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0038] Figure 1 This is a wellhead construction layout diagram of an ultra-high pressure hydraulic deep penetration perforation device for under-injected wells in low-permeability oil reservoirs, according to an embodiment of this disclosure.

[0039] In the diagram: 1. Injection pump; 2. Hoses; 3. Pressure hose; 4. Ultrasonic monitor; 5. Pressurization mechanism; 6. Quantitative sand dispenser; 7. Gyroscope; 8. Pressure nozzle; 9. Magnetic depth gauge. Detailed Implementation

[0040] The present disclosure is described below based on embodiments; however, it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, certain specific details are described in detail. However, those skilled in the art will fully understand the present disclosure for the parts not described in detail.

[0041] Furthermore, unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to."

[0042] The ultra-high pressure hydraulic deep penetration perforation device for under-injection wells in low-permeability oil reservoirs disclosed herein is the same as that of conventional hydraulic deep penetration perforation devices, generally including surface pipelines, supporting equipment and perforation equipment. However, this disclosure has improvements and adjustments to the specific surface pipelines, supporting equipment and perforation equipment.

[0043] The following are preferred embodiments of this disclosure.

[0044] Figure 1 This is a wellhead construction layout diagram of an ultra-high pressure hydraulic deep penetration perforation device for under-injected wells in low-permeability oil reservoirs, according to an embodiment of this disclosure; Figure 1 As shown, the ultra-high pressure hydraulic deep penetration perforation device for under-injected wells in low-permeability oil reservoirs includes supporting equipment and perforation equipment. In the supporting equipment, the injection pump 1, pressure-resistant hose 3, and pressure-resistant nozzle 8 are configured differently from conventional hydraulic deep penetration perforation devices. In this embodiment, the power of the injection pump 1 is 120-200KW, the internal pressure of the pressure-resistant hose 3 is >100MPa, and the material of the pressure-resistant nozzle 8 is molybdenum-based titanium alloy. Furthermore, unlike conventional hydraulic deep penetration perforation devices that use tubing for delivery, in this embodiment, the perforation equipment is specifically delivered to the well via the pressure-resistant hose 3, which is delivered via a hose reel 2.

[0045] In this embodiment, the pressure-resistant hose, steel cable, and cable are conveyed by a three-wire integrated clamp, which is a clamp with three holes, each used to pass through the pressure-resistant hose, steel cable, and cable.

[0046] In this embodiment, the supporting equipment includes a quantitative sand adding mechanism, which includes a quantitative sand adder 6. The quantitative sand adder 6 is connected to a pressurizing device 5 and an ultrasonic monitor 4. The pressurizing device 5 is used to control the sand adding speed of the quantitative sand adder 6, and the ultrasonic monitor 4 is used to control the amount of sand added by the quantitative sand adder 6.

[0047] In this embodiment, the supporting equipment also includes a magnetic depth gauge 9 and a gyroscope 7, wherein the magnetic depth gauge 9 and the gyroscope 7 are used to calibrate the working depth.

[0048] In this embodiment, the method for performing ultra-high pressure hydraulic deep penetration perforation perforation on under-injected wells in low-permeability oil reservoirs using the ultra-high pressure hydraulic deep penetration perforation perforation device for low-permeability oil reservoirs as described in this disclosure includes the following steps:

[0049] 1. Based on the well selection conditions of the hydraulic deep penetration perforation process, under-injected wells are screened. The under-injected wells are those that do not meet the water injection standards of the oilfield. In this embodiment, the specific screening method can adopt conventional technology in the field.

[0050] 2. For the selected under-injected wells, the design is optimized to determine the perforation layer, number of perforations and construction parameters for a single well. In this embodiment, the perforation layer and number of perforations are specifically determined based on the single-well production data, cumulative water injection volume and production status of connected oil wells commonly used in the art.

[0051] 3. Complete the preparatory work before water injection construction. The specific preparatory work includes: removing the original well tubing, lowering the well tubing to ensure the wellbore is intact; moving the perforating equipment to the construction site, setting it up, and testing its safety and integrity; and pressure testing the wellhead, manifold, valve group, etc. In this embodiment, the above preparatory work is carried out using conventional and commonly used techniques in the field.

[0052] 4. Based on the determined number of perforations per well and per layer, ultra-high pressure hydraulic deep penetration drilling is carried out. In this embodiment, the specific construction procedures are as follows:

[0053] (1) Use a tubing trip simulator to pass through the perforated section to ensure that the perforating equipment can pass through the perforated section safely.

[0054] (2) The three-line integrated coupling is adopted to ensure that the steel cable, pressure-resistant hose and cable are in a state of non-interference, and the perforation equipment is quickly and stably sent to the designated position. The target layer is accurately laid out according to the construction design requirements, and the zero point is corrected at the wellhead plane.

[0055] (3) Calculate the location of each perforation point and the location of the coupling at the layer position. First, calibrate the working depth by lowering the steel cable into the magnetic depth gauge 9 and gyroscope 7. The specific calculation formula is as follows:

[0056] H 射孔 / 接箍深度 =L 表显深度 +△L 自然伸长 +(h 套补距 -h 四通高 -h 防喷器 )+△H 前磁误差 ;

[0057] In the formula: △L 自然伸长 =H 射孔 / 接箍深度 *0.003;

[0058] H 射孔 / 接箍深度 This refers to the actual depth of the perforation / coupling.

[0059] L 表显深度 This is for displaying the well depth on the control panel;

[0060] △L 自然伸长 This is the natural elongation length of the steel wire;

[0061] h 套补距 Basic data;

[0062] h 四通高 Basic data;

[0063] h 防喷器 Basic data;

[0064] △H 前磁误差 These are actual measured data.

[0065] (4) Lower the steel cable into the vicinity of the lowest perforation point, start the front magnetic positioning calibration depth, find the joint position of the two closest points, and check the displayed depth and actual depth. If the error is less than 0.01m, it is considered accurate. If the error is greater than 0.01m, add the front magnetic error correction formula above.

[0066] (5) Lower the steel cable to the lowest perforation point, connect the perforation equipment, supporting equipment and ground pipelines, and carry out pressure testing to ensure that the jet channel is normal.

[0067] (6) Control the internal pressure, sand addition amount and speed, and construction time according to the design requirements. Perform perforation on the target layer according to the construction design requirements to achieve control over the single hole penetration depth and hole diameter. In this embodiment, the controllable range of the system is: cable depth less than 2500m, internal pressure 100-200MPa, construction time 20-40min, sand addition speed less than 5.0kg / min, diameter 1.2-2.0cm, and penetration hole depth 4-5m.

[0068] (7) Once the construction meets the requirements, complete the first section of construction. From bottom to top, lift the steel cable and repeat steps (5) and (6) to complete the construction of all points.

[0069] (8) After completing the construction of all the hole enlargement points, start the motor to lift the steel cable at a constant speed and bring the instrument out of the wellhead.

[0070] (9) Run the sand flushing string to the bottom of the artificial well, complete the sand flushing according to the downhole operation requirements, and then complete the well according to the well completion design requirements.

[0071] Based on the above, the ultra-high pressure hydraulic deep penetration perforation device and method for under-injected wells in low-permeability oil reservoirs described in this disclosure can achieve convenient construction, targeted unblocking, deep penetration, and layered water control in one operation. The technical principle is as follows:

[0072] (1) In order to achieve rapid lifting and convenient construction, this invention adopts a new three-line integrated transmission technology that is different from conventional technology. That is, the three-line integrated coupling is used to ensure that the steel cable, pressure-resistant hose and cable are transmitted in a state of non-interference, which is safe and reliable. The three points are fixed, avoiding the engineering problems of single line function and two lines being entangled with each other. It can quickly and stably send the instrument to the designated position.

[0073] (2) The ultra-high pressure hydraulic deep penetration hole device disclosed herein adopts advanced foreign ultra-high pressure (internal pressure > 100MPa) hose transmission technology, combined with magnetic positioning integrated depth correction and anchoring technology to achieve targeted unblocking, achieve accurate depth determination, and the error accuracy is less than 0.1m;

[0074] (3) The ultra-high pressure hydraulic deep penetration perforation device disclosed herein utilizes the overall control technology of injection pump 1 (specifically a high-power electric pump with a power of 200KW, used to stabilize output power and enhance jet kinetic energy), pressure-resistant hose 3 (specifically an ultra-pressure-resistant hose, used for efficient transmission of jet kinetic energy), and pressure-resistant nozzle (specifically a molybdenum-based titanium alloy, used to improve jet time) to achieve stable ultra-high speed sand-carrying directional jet, achieving deep penetration with a hole depth of 4-5m (currently the penetration depth of hydraulic deep penetration technology is 1.5-2.0m) and an orifice diameter of 1.2-2.0cm; based on the significant breakthrough in penetration depth, it can remove deep contamination, effectively break through the near-well contamination zone, increase the discharge area, and the single-hole discharge area is large, more than 10 times that of conventional perforations.

[0075] (4) Based on the above-mentioned technical characteristics of accurate depth and large single-hole discharge area, it is possible to achieve a large number of perforations in one run, generally 10-15 points per well (the conventional number of perforations in one run is 4-6 points). With a large number of perforations in one run, personalized and precise perforation methods can be carried out according to different layer requirements, that is, multi-layer precise control on demand can be adopted to effectively unblock the entire well of the under-injected water well and achieve the purpose of layered water control.

[0076] In summary, the technological system disclosed herein has the following technical characteristics:

[0077] 1. Accurate depth determination, with an error precision of less than 0.1m;

[0078] 2. It has a large drilling depth, with holes 4-5m deep, which can remove deep contamination;

[0079] 3. Large single-hole drainage area, with an orifice diameter of 1.2-2.0cm, the drainage area is more than 10 times that of conventional perforations;

[0080] 4. Simple construction, high efficiency, short single-hole perforation cycle, high perforation efficiency, single-hole cycle 30-40min;

[0081] 5. Wide adjustable depth range, with an insertion depth of up to 2500m and internal pressure resistance of over 200MPa;

[0082] 6. A single run involves a large number of perforations, typically 10-15 points per well;

[0083] 7. Due to the high strength and wear resistance of the pressure-resistant nozzle, it can be used for 100 well expansions without replacement and can be used for more than 6 wells, thus achieving the goal of long-term construction without replacement;

[0084] 8. The three-line integrated transmission method ensures that the steel cable, pressure-resistant hose and cable do not interfere with each other during transmission, which is safe and reliable, improves the speed of lifting and lowering, and effectively avoids the engineering problems of single line function and two lines being tangled together.

[0085] Application examples

[0086] For the low-permeability M block on the periphery of Daqing Oilfield, the method of this invention was applied for multi-layer integrated unblocking and injection enhancement. The specific application process and effects are as follows:

[0087] 1. Screening of under-injected well M-1 in the low-permeability M block of Daqing Oilfield. This well is located in the L fault block, with five sedimentary units perforated throughout. It was put into production in June 2013, with an initial injection pressure of 14.0 MPa and a daily injection rate of 45 m³ / s. 3 45m daily actual bet 3 The well has a total water injection volume of 8.99 × 10⁻⁶. 4 m 3 The current injection pressure is 14.0 MPa, and the daily injection rate is 45 m³. 3 15m daily betting 3 The well is deeply blocked, resulting in severe under-injection. The well inclination is less than 15° and the bottom boundary of the perforation is 69.5m from the bottom of the artificial well, which meets the well selection conditions for the ultra-high pressure hydraulic deep penetration perforation process.

[0088] 2. The oil production team depressurizes the well.

[0089] 3. Prepare the perforation equipment and supporting equipment required for the ultra-high pressure hydraulic deep penetration perforation process. At the same time, the work team will carry out the work on the water injection string.

[0090] 4. The work team will perform pretreatment work on the wellbore, including: removing the original well casing, flushing sand, and scraping to ensure that the wellbore is free from deformation;

[0091] 5. The perforation thickness of this well is 6.2m, with an effective thickness of 3.5m. Seven perforations were designed. The calculations for this deep penetration and enlargement are shown in Table 2 below:

[0092] Table 2M-1: Depth and Number of Enlarged Holes in Deep Pipeline

[0093]

[0094] Note: Casing coupling locations near deep penetration sections: 1030.19m, 1041.07m, 1051.91m, 1062.68m, 1073.83m, 1084.66m, 1095.41m, 1106.39m, 1117.31m, 1128.05m.

[0095] The original well perforation zone: 1068.5m~1112.7m.

[0096] 6. Downloading the emulator up to 1113.0m proceeded without any issues;

[0097] 7. Lower the ultra-high pressure hydraulic deep penetration hole downhole tool to near the designed deepest point;

[0098] 8. The front magnetic positioning points 1106.39m and 1117.31m were used to determine the coupling positions. The calculation results showed that the error between the two coupling points was less than 0.01m, indicating accurate depth determination.

[0099] 9. Adjust the perforation downhole tool to the designed deepest point of 1112.4m;

[0100] 10. Connect the ultra-high pressure hydraulic deep penetration hole equipment, supporting equipment and ground pipelines, carry out hole enlargement construction according to design requirements, control the construction pressure at 160MPa, add 125kg of sand, and complete the first layer construction in 30 minutes.

[0101] 11. Raise the equipment to the hole enlargement depth of layers 2-7, repeat steps 7-10, and complete the construction of layers 2-7;

[0102] 12. After the construction of the ultra-high pressure hydraulic deep penetration hole is completed, lift the equipment and instruments out of the wellhead;

[0103] 13. Run the sand flushing string to flush to the bottom of the artificial well, and then run the completion string;

[0104] 14. Tests showed that the initial injection pressure of the well was 12.5 MPa. Measures were taken to reduce the pressure by 1.5 MPa, increasing the daily injection capacity by 30 m³. 3 It can complete injection, and the pressure reduction and injection enhancement effects are significant. Currently, the pressure-resistant nozzle in this equipment has completed 2400 minutes of construction in 9 wells and 80 layers, and the pressure-resistant nozzle has no overall deformation and the nozzle diameter has basically remained unchanged.

[0105] The above application examples demonstrate that the device and method of the present invention can achieve fixed-point and fixed-azimuth perforation, effectively break through the near-well contamination zone, and increase the drainage area. Furthermore, based on different formations, personalized multi-point precise perforation can be implemented to effectively unblock under-injected wells, achieving a unified unblocking purpose of targeted unblocking, deep penetration, and stratified water control. The unblocking and injection enhancement measures are highly effective, significantly reducing the injection pressure of under-injected wells, increasing the injection volume, and achieving effective unblocking, providing technical support for unblocking under-injected wells in peripheral low-permeability reservoirs.

[0106] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A device for ultra-high pressure hydraulic deep penetration perforation wells in low-permeability oil reservoirs, characterized in that, include: Supporting equipment and perforation equipment; The supporting equipment includes an injection pump, a pressure-resistant hose, and a pressure-resistant nozzle. The power of the injection pump is 120-200KW, the internal pressure of the pressure-resistant hose is >100MPa, and the material of the pressure-resistant nozzle is molybdenum-based titanium alloy.

2. The ultra-high pressure hydraulic deep penetration perforation device for under-injection wells in low-permeability oil reservoirs according to claim 1, characterized in that, Also includes: The three-wire integrated clamp is equipped with three holes that allow the pressure-resistant hose, steel cable, and cable to pass through respectively.

3. The ultra-high pressure hydraulic deep penetration perforation device for under-injection wells in low-permeability oil reservoirs according to claim 2, characterized in that: The supporting equipment also includes a quantitative sand adding mechanism, which includes a quantitative sand adder. The quantitative sand adder is connected to a pressurizing device and an ultrasonic monitor. The pressurizing device is used to control the sand adding speed, and the ultrasonic monitor is used to control the sand adding amount.

4. The ultra-high pressure hydraulic deep penetration perforation device for under-injection wells in low-permeability oil reservoirs according to claim 3, characterized in that: The supporting equipment also includes a magnetic depth gauge and a gyroscope, which are used to calibrate the working depth.

5. The ultra-high pressure hydraulic deep penetration perforation device for under-injection wells in low-permeability oil reservoirs according to any one of claims 1-4, characterized in that: The pressure-resistant hose is delivered via a hose reel.

6. A method for ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs, characterized in that, include: Using the ultra-high pressure hydraulic deep penetration perforation device as described in any one of claims 1-5, the wells in low-permeability oil reservoirs that are under-injected are unblocked and injected.

7. The method for ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs according to claim 6, characterized in that: The perforating equipment is delivered downhole via a pressure-resistant hose.

8. The method for ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs according to claim 6 or 7, characterized in that: The pressure-resistant hose, steel cable, and electrical cable are conveyed via a three-in-one clamp.

9. The method for ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs according to claim 8, characterized in that, The method includes calculating the locations of each perforation point and the coupling position at the stratigraphic level, and the calculation formula is: H-perforation / coupling depth = L-indicated depth + ΔL-natural elongation + (h-sleeve gap - h-way height - h-blowout preventer) + ΔH 前磁误差 ; Where: △L natural elongation = H perforation / coupling depth * 0.003; H-perforation / coupling depth is the actual well depth of the perforation / coupling; The L-display depth is the well depth shown on the control panel; △L is the natural elongation length of the steel wire; h-set spacing is the basic data; h-type height is the basic data; h-blower preventer is based on the data; △H 前磁误差 These are actual measured data.

10. The method for ultra-high pressure hydraulic deep penetration perforation in under-injected wells of low-permeability oil reservoirs according to claim 9, characterized in that: The method further includes verifying the calculation results of each perforation point and coupling position at the stratigraphic location, and the verification method includes: Lower the steel cable to the lowest perforation point, activate the pre-magnetic positioning calibration depth, find the joint position of the two closest points, and verify the displayed depth and actual depth. If the error is less than 0.01m, it is considered accurate. If the error is greater than 0.01m, the pre-magnetic error correction calculation formula is added.

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