Preparation and application method of low-pressure high-leakage oil well temporary plugging liquid

Abstract

The invention relates to the field of oil and gas exploitation, and discloses a preparation and application method of a low-pressure high-leakage oil well temporary plugging fluid, the preparation method of the low-pressure high-leakage oil well temporary plugging fluid comprises the following steps: preparing a prepad fluid comprising an emulsifier, polyacrylamide, sodium hydroxide and water; preparing a temporary plugging liquid, wherein the temporary plugging liquid comprises a bactericide, sodium hydroxide, xanthan gum or carboxymethyl starch, super absorbent resin, water-soluble elastic particle HJK series and water; preparing an initiation solution, wherein the initiation solution comprises sodium hydroxide, borax and water; by using the specially-made prepad fluid, the temporary plugging fluid and the initiating fluid, the leakage rate of the high-leakage well can be effectively reduced, the prepad fluid can improve conditions in a shaft, and a good foundation is provided for effective injection of the temporary plugging fluid. The super absorbent resin and the water-soluble elastic particles in the temporary plugging liquid can absorb water and expand in shot holes and leakage channels of a shaft, a tight temporary plugging layer is formed, and leakage of oil and gas is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploitation, and in particular to a preparation and application method of a temporary plugging fluid for a low-pressure high-loss oil well. Background Art

[0002] During the production of oil and gas wells, sand often appears in the wellbore, especially in horizontal wells, which is more serious and affects the connectivity between the wellbore and the formation. The commonly used method is to lower a flushing pipe into the sand producing position in the wellbore and bring the formation sand out of the wellhead through water circulation. This method is effective in most oil and gas wells, but it has no effect on wells with severe leakage (i.e., the leakage is too large and the conventional sand flushing method cannot establish an effective circulation). The reason is that part or all of the working fluid pumped into the wellbore leaks into the formation, resulting in the outlet return fluid volume being unable to meet the requirements of the annular space reverse velocity for the sand flushing, thereby reducing the oil well production or even stopping production.

[0003] In the prior art, the methods for solving the sand flushing problem in malignant leakage wells mainly include the following:

[0004] High viscosity sand washing fluid:

[0005] Disadvantages: After the sand flushing is completed, a large amount of high-viscosity working fluid is retained in the reservoir pores, affecting the recovery rate. At the same time, the high-viscosity working fluid has a high circulation pressure during the circulation process, which is easy to cause further leakage.

[0006] Inert plugging materials plugging:

[0007] Disadvantages: When the inert plugging material is used with the working fluid to plug the leak first and then the sand flushing operation is carried out, the plugging material with strong rigidity is easy to cause the pump to get stuck, affecting the construction progress. The plugging material entering the formation is not easy to be discharged and degraded, which is easy to block the oil layer and reduce the recovery rate. During the sand flushing process, the plugging agent will be peeled off with the turbulent flushing of the working fluid, causing secondary leakage.

[0008] Oilfield treated water replenishes formation pressure:

[0009] Disadvantages: Replenishing oilfield treated water requires accurate estimation of the amount of fluid replenishment, and currently the amount of fluid replenishment required for wells in different blocks ranges from several hundred to several thousand cubic meters. The fluid replenishment construction period is long and the cost is high. During the sand flushing process, the sand bridge will be destroyed, exposing new leakage points, resulting in malignant leakage, so that secondary fluid replenishment is required.

[0010] Nitrogen foam sandblasting:

[0011] Disadvantages: The construction is complicated and requires the cooperation of nitrogen production skid and coiled tubing. If the nitrogen is impure, it is easy to cause explosion. In addition, improper control of the liquid column pressure of the nitrogen foam liquid will cause the static liquid column pressure to be seriously lower than the formation pressure, resulting in unstable reservoir structure. While flushing sand, it is easy to cause secondary sand production in the formation and even increase the risk of bottom hole collapse.

[0012] The present invention provides a temporary plugging fluid for low-pressure and high-loss oil wells and an application method thereof, aiming to overcome the deficiencies of the above-mentioned prior art. Summary of the invention

[0013] In view of the shortcomings of the prior art, the present invention provides a method for preparing and applying a temporary plugging fluid for low-pressure and high-loss oil wells, which can effectively solve the leakage problems in oil well sand flushing, plug drilling and scale drilling operations, ensure the establishment of a circulating loss volume that meets the construction requirements, and has the advantages of low operating cost, no need to add other special vehicles and equipment, safety and reliability, and simple construction.

[0014] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a temporary plugging fluid for a low-pressure high-loss oil well comprises the following steps:

[0015] Prepare pre-liquid: including emulsifier, polyacrylamide, sodium hydroxide and water;

[0016] Prepare temporary plugging liquid: including bactericide, sodium hydroxide, xanthan gum or carboxymethyl starch, super absorbent resin, water-soluble elastic particles HJK series, water;

[0017] Prepare the initiating solution: including sodium hydroxide, borax and water.

[0018] Preferably, the pre-pad fluid, temporary plugging fluid and initiating fluid of the temporary plugging fluid for low-pressure high leakage oil wells have the following components in terms of weight percentage:

[0019] The pre-fluid comprises, by weight percentage, 0.05% to 0.1% of emulsifier ABSN, 0.1% to 0.3% of polyacrylamide, 0.05% to 0.1% of sodium hydroxide, and the balance is water;

[0020] The temporary plugging liquid comprises, by weight percentage, 0.05% to 0.1% of a bactericide, 0.1% to 0.3% of sodium hydroxide, 0.3% to 0.5% of xanthan gum or 1% to 1.5% of carboxymethyl starch, 0.3% to 0.5% of a highly absorbent resin, 1% to 10% of HJK ​​series water-soluble elastic particles, and the balance being water;

[0021] The initiating liquid comprises, by weight percentage, 0.05% to 0.1% of sodium hydroxide, 0.1% to 0.5% of borax, and the balance is water.

[0022] Preferably, the particle size of the super absorbent resin is 5 to 20 meshes.

[0023] Preferably, the super absorbent resin is a dry agent, which is pre-absorbed and swollen before use and then added into the system to increase the temporary plugging effect.

[0024] Preferably, the water-soluble elastic particles are added during on-site construction so that they can fully absorb water and swell in the blasthole and the leakage channel, thereby further enhancing the temporary plugging effect.

[0025] The present invention also provides an application method of a temporary plugging fluid for a low-pressure high-loss oil well, comprising the following steps:

[0026] S1. Close the oil well blowout preventer and tubing cock, and squeeze 20 to 30 cubic meters of pre-fluid from the casing valve into the wellbore in the reverse direction;

[0027] S2. Reversely squeeze temporary plugging fluid from the casing valve at a displacement of 350L / s to 400L / s until the wellhead pressure rises to above 10MPa;

[0028] S3, squeeze 10 to 20 cubic meters of initiating liquid in the reverse direction from the casing valve at a displacement of 350L / s to 400L / s;

[0029] S4. Squeeze the displacement fluid in reverse from the casing valve at a displacement rate of 350L / s to 450L / s. The volume of the displacement fluid is determined according to the wellbore volume.

[0030] S5. After sufficient displacement fluid is injected, the wellbore is pressurized for 20 to 40 minutes;

[0031] S6. Open the well to drain the fluid, measure the loss, and after confirming that the loss requirements are met, proceed with sand flushing, plug drilling and scale drilling operations.

[0032] Preferably, the size of the water-soluble elastic particles in the temporary plugging fluid is adjusted according to the well conditions, with particles of 10 mm to 15 mm being used in conventional perforation sections and particles of 1 mm to 10 mm being used in hydraulic sandblasting perforation sections.

[0033] Preferably, after the extrusion pressure of the temporary plugging fluid rises to above 10 MPa, the pressure is maintained for at least 5 minutes to ensure that the temporary plugging fluid is fully distributed in the wellbore.

[0034] The present invention provides a method for preparing and applying a temporary plugging fluid for low-pressure and high-loss oil wells. It has the following beneficial effects:

[0035] 1. The present invention can effectively reduce the leakage rate of high leakage wells by using special pre-flushing fluid, temporary plugging fluid and initiating fluid. The pre-flushing fluid can improve the conditions in the wellbore and provide a good basis for the effective injection of the temporary plugging fluid. The highly absorbent resin and water-soluble elastic particles in the temporary plugging fluid can absorb water and swell in the blastholes and leakage channels of the wellbore to form a tight temporary plugging layer, which significantly reduces the leakage of oil and gas.

[0036] 2. The present invention ensures that the temporary plugging fluid can play a role at the appropriate position and time by accurately controlling the injection rate and pressure, as well as the use of the triggering fluid. This control not only improves the efficiency of the operation, but also increases the safety of the operation, because the solidification or expansion of the temporary plugging fluid is controllable, avoiding unnecessary formation pressure increase or other potential risks.

[0037] 3. The temporary plugging fluid components used in the present invention, such as xanthan gum and carboxymethyl starch, are biodegradable polysaccharide polymers with a short natural degradation cycle and little damage to the reservoir. This environmentally friendly property makes it easy to recover the oil well after operation and reduces the long-term impact on the environment.

[0038] 4. The materials used in the present invention are easy to obtain and reasonably priced, the preparation process is simple, and no special equipment or complex technical support is required, which greatly reduces the operating cost. In addition, due to the reduction of leakage, the output efficiency of the oil well is improved, thereby increasing the economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic flow chart of the application method of the present invention;

[0040] Figure 2 It is a schematic diagram of the application and process principle of the present invention.

[0041] Among them, 1. Surface casing; 2. Oil layer casing; 3. Oil pipe; 4. Blast hole; 5. Temporary plugging particles; 6. Oil layer leakage channel. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of the present invention.

[0043] The invention provides a preparation method of a temporary plugging fluid for a low-pressure high-loss oil well and an application method thereof, which are used to effectively manage the oil well leakage problem, especially in a high-loss oil well.

[0044] The present invention provides a method for preparing a temporary plugging fluid for a low-pressure high-loss oil well, comprising the following steps:

[0045] 1. Prepare pre-fluid

[0046] Formula: emulsifier ABSN 0.05% to 0.1%, polyacrylamide 0.1% to 0.3%, sodium hydroxide 0.05% to 0.1%, and the balance is water.

[0047] Function: The pre-fluid is used to improve the internal environment of the wellbore and prepare for the injection of temporary plugging fluid.

[0048] 2. Prepare temporary plugging fluid

[0049] Formula: bactericide 0.05% to 0.1%, sodium hydroxide 0.1% to 0.3%, xanthan gum 0.3% to 0.5% or carboxymethyl starch 1% to 1.5%, super absorbent resin 0.3% to 0.5%, water-soluble elastic particles HJK series 1% to 10%, and the balance is water.

[0050] Features: The temporary plugging fluid contains highly absorbent resin and water-soluble elastic particles, which can absorb water and swell in the blasthole and leakage channel to form an effective temporary plugging.

[0051] 3. Prepare the initiation solution

[0052] Formula: Sodium hydroxide 0.05% to 0.1%, borax 0.1% to 0.5%, and the balance is water.

[0053] Function: The initiating fluid is used to stimulate the reaction of the temporary plugging fluid, causing it to solidify or expand at the appropriate position.

[0054] Please see attached Figure 1 -Attached Figure 2 The present invention also provides an application method of the low-pressure high-loss oil well temporary plugging fluid, comprising the following steps:

[0055] 1. Shut down the equipment in the well

[0056] First, close the oil well blowout preventer and the tubing cock. This step is to ensure that during the injection of temporary plugging fluid, there is no flow of other fluids in the well, so as to avoid any external factors affecting the temporary plugging effect.

[0057] 2. Inject pre-fluid

[0058] From the casing valve, 20 to 30 cubic meters of pre-fluid are squeezed into the wellbore in the reverse direction. The pre-fluid enters through the surface casing 1 and the oil layer casing 2. Its main function is to prepare the wellbore, improve the well environment, and create suitable conditions for the subsequent injection of temporary plugging fluid.

[0059] 3. Inject temporary plugging fluid

[0060] Continue to squeeze the temporary plugging fluid in reverse from the casing valve at a displacement of 350L / s to 400L / s until the wellhead pressure rises to above 10MPa. The temporary plugging fluid contains highly absorbent resin and water-soluble elastic particles, and enters the bottom of the well through the oil pipe 3 and the blasthole 4, directly reaching the oil layer leakage channel 6.

[0061] 4. Injection of initiating fluid

[0062] Use the same flow rate as the temporary plugging liquid (350L / s to 400L / s) to squeeze 10 to 20 cubic meters of initiating liquid in the reverse direction. The main function of the initiating liquid is to trigger or accelerate the solidification or reaction process of the temporary plugging liquid to ensure that the temporary plugging particles 5 are effectively solidified or expanded in the leakage channel 6.

[0063] 5. Inject displacement fluid

[0064] The displacement fluid is squeezed in reverse from the casing valve at a displacement rate of 350L / s to 450L / s. The volume of the displacement fluid is determined according to the wellbore volume. The function of the displacement fluid is to push all the injected liquid into the leakage channel to ensure that the temporary plugging particles completely block the leakage area.

[0065] 6. Pressure bearing and drainage

[0066] After injecting sufficient displacement fluid, keep the wellbore under pressure for 20 to 40 minutes, and then open the well to drain the fluid. This step is to test the temporary plugging effect and confirm whether the expected plugging effect is achieved by measuring the leakage volume.

[0067] 7. Follow-up work

[0068] Once the loss volume is confirmed to meet the requirements, sand flushing, plugging and drilling operations can be carried out. These operations can effectively restore or increase the production capacity of the well.

[0069] The present invention can effectively reduce the leakage rate of high leakage wells by using special pre-flushing fluid, temporary plugging fluid and initiating fluid. The pre-flushing fluid can improve the conditions in the wellbore and provide a good basis for the effective injection of the temporary plugging fluid. The highly absorbent resin and water-soluble elastic particles in the temporary plugging fluid can absorb water and swell in the blastholes and leakage channels of the wellbore to form a tight temporary plugging layer, which significantly reduces the leakage of oil and gas.

[0070] In summary, the preparation and application method of the temporary plugging fluid for low-pressure and high-loss oil wells provided by the present invention not only effectively solves the leakage problem, but also improves the safety and environmental sustainability of oil well operations, while reducing economic costs, providing an efficient and economical solution for the oil and gas industry.

[0071] In order to better understand the present invention, the above method is described in detail below in conjunction with specific embodiments.

[0072] Embodiment 1:

[0073] Applicable to oil wells with leakage not exceeding 160L / min.

[0074] Pre-fluid formula:

[0075] Emulsifier ABSN: 0.05% to 0.1%

[0076] Polyacrylamide: 0.1% to 0.3%

[0077] Sodium hydroxide: 0.05% to 0.1%

[0078] Water: Balance

[0079] Temporary plugging fluid formula:

[0080] Fungicide: 0.05% to 0.1%

[0081] Sodium hydroxide: 0.1% to 0.3%

[0082] Xanthan gum or carboxymethyl starch: 0.3% to 0.5% or 1% to 1.5%

[0083] Super absorbent resin (5-20 mesh): 0.3% to 0.5%

[0084] Water-soluble elastic particles HJK series: 1% to 3%

[0085] Water: Balance

[0086] Initiator fluid formula:

[0087] Sodium hydroxide: 0.05% to 0.1%

[0088] Borax: 0.1% to 0.5%

[0089] Water: Balance

[0090] Embodiment 2:

[0091] Suitable for oil wells with leakage rates between 160L / min and 250L / min.

[0092] Pre-pad liquid formula: same as Example 1

[0093] Temporary plugging fluid formula:

[0094] Fungicide: 0.05% to 0.1%

[0095] Sodium hydroxide: 0.1% to 0.3%

[0096] Xanthan gum or carboxymethyl starch: 0.3% to 0.5% or 1% to 1.5%

[0097] Super absorbent resin (5-20 mesh): 0.3% to 0.5%

[0098] Water-soluble elastic particles HJK series: 1% to 5%

[0099] Water: Balance

[0100] Initiator liquid formula: same as Example 1

[0101] Embodiment 3:

[0102] Applicable to oil wells with leakage greater than 250L / min.

[0103] Pre-pad liquid formula: same as Example 1

[0104] Temporary plugging fluid formula:

[0105] Fungicide: 0.05% to 0.1%

[0106] Sodium hydroxide: 0.1% to 0.3%

[0107] Xanthan gum or carboxymethyl starch: 0.3% to 0.5% or 1% to 1.5%

[0108] Super absorbent resin (5-20 mesh): 0.3% to 0.5%

[0109] Water-soluble elastic particles HJK series: 2% to 10%

[0110] Water: Balance

[0111] Initiator liquid formula: same as Example 1

[0112] Each of the embodiments 1-3 can effectively plug wells with different degrees of leakage, has good plugging effect, is easy to operate and has low cost. These embodiments adapt to different degrees of leakage conditions through different proportions of components, ensuring wide application and effectiveness in various situations.

[0113] Example 4: Application of temporary plugging fluid in oil well sand flushing operations

[0114] Purpose: To use temporary plugging fluid to perform sand flushing operations in high-loss oil wells to reduce losses and ensure operational efficiency.

[0115] Method steps:

[0116] 1. Turn off the safety equipment in the well: turn off the blowout preventer and tubing cock, and prepare the wellbore for liquid injection.

[0117] 2. Injection of pre-fluid: 10 to 30 cubic meters of pre-fluid is squeezed into the wellbore through the casing valve to optimize the internal environment of the wellbore.

[0118] 3. Inject temporary plugging fluid: Inject temporary plugging fluid in reverse from the casing valve at a displacement of 350L / s to 400L / s until the wellhead pressure reaches above 10MPa to form an effective temporary plugging layer.

[0119] 4. Inject initiating liquid: Continue to inject 10 to 20 cubic meters of initiating liquid at a rate of 350L / s to 400L / s to promote the solidification or reaction of the temporary plugging liquid.

[0120] 5. Inject displacement fluid: Inject displacement fluid in reverse from the casing valve at a displacement rate of 350L / s to 450L / s. The volume is determined according to the wellbore volume to ensure uniform distribution of temporary plugging fluid.

[0121] 6. Maintain pressure and drain fluid: After injecting sufficient displacement fluid, the wellbore is under pressure for more than 20 minutes, and then the well is opened to drain fluid.

[0122] 7. Perform sand flushing operation: Perform normal sand flushing operation on the lower flushing pipe.

[0123] Example 5: Application of temporary plugging fluid in oil well plugging and drilling operations

[0124] Purpose: To use temporary plugging fluid to perform plugging and drilling operations in high-loss oil wells to effectively control the loss during the operation.

[0125] Method steps:

[0126] 1. Turn off the safety equipment in the well: Same as Example 4, turn off the well blowout preventer and the tubing cock.

[0127] 2. Injection of pre-pad liquid: Same as in Example 4, 10 to 30 cubic meters of pre-pad liquid are squeezed in reverse from the casing valve.

[0128] 3. Injection of temporary plugging fluid: As in Example 4, the temporary plugging fluid is injected in reverse at a displacement of 350 L / s to 400 L / s, and the wellhead pressure rises to above 10 MPa.

[0129] 4. Injection of initiating liquid: As in Example 4, continue to inject 10 to 20 cubic meters of initiating liquid at the same rate.

[0130] 5. Injection of displacement fluid: Same as in Example 4, the displacement fluid is injected in reverse at a displacement rate of 350 L / s to 450 L / s, and the amount is determined according to the wellbore volume.

[0131] 6. Maintain pressure and drain fluid: After injecting sufficient displacement fluid, the wellbore is pressurized for 20 to 40 minutes and then the well is opened to drain fluid.

[0132] 7. Perform plug drilling and scale drilling operations: lower the drill bit to perform plug drilling and scale drilling operations.

[0133] Examples 4-5 demonstrate how to apply the temporary plugging fluid of the present invention in different types of oil well operations, through effective liquid injection and pressure maintenance steps, to minimize leakage in oil well operations and ensure smooth operation.

[0134] Example 6: Temporary plugging application of horizontal well sand flushing operation

[0135] background:

[0136] Well type: horizontal well

[0137] Well depth and horizontal section: 5,200 meters total depth, including 1,600 meters horizontal section

[0138] Production method: perforation fracturing

[0139] Loss degree: Loss of return

[0140] Operation team: Coiled tubing team

[0141] Purpose of operation: Sand blasting

[0142] Temporary blocking operation process:

[0143] 1. Temporary plugging fluid injection:

[0144] Pre-fluid: 30 cubic meters of back-extrusion

[0145] Temporary plugging liquid: 120 cubic meters Triggering liquid: 20 cubic meters

[0146] Displacement fluid: 35 cubic meters

[0147] 2. Pressure and pump stop processing:

[0148] The wellhead pressure gradually rises to 14MPa

[0149] After stopping the pump for 20 minutes, the pressure dropped back to 5MPa and stabilized.

[0150] Steady pressure for 30 minutes

[0151] 3. Drainage and measurement:

[0152] After 15 minutes of draining the well, no water came out of the wellhead.

[0153] After drilling and circulating for 1 hour, the leakage was measured to be 10L / min, which is far lower than the allowed 50L / min. 4. Operation results:

[0154] There is no significant increase in the amount of leakage during the sand flushing process

[0155] The well was successfully completed and production was restored to the pre-workover level after 5 days.

[0156] Example 7: Temporary plugging application of drilling bridge plug operation

[0157] background:

[0158] Well type: horizontal well

[0159] Well depth and horizontal section: 3200m total depth, 1200m horizontal section Production method: Perforation and fracturing Loss rate: 450L / min Operation team: Coiled tubing team Operation purpose: Drilling bridge plugs (9) Temporary plugging Operation process:

[0160] 1. Temporary plugging fluid injection:

[0161] Pre-fluid: 20 cubic meters Temporary plugging fluid: 80 cubic meters Triggering fluid: 15 cubic meters Displacement fluid: 35 cubic meters 2. Pressure and pump stop processing:

[0162] The wellhead pressure gradually rose to 12MPa. After the pump was stopped for 15 minutes, the pressure dropped back to 4MPa and stabilized.

[0163] 20 minutes of steady pressure

[0164] 3. Drainage and measurement:

[0165] After 10 minutes of draining the well, no water came out of the wellhead

[0166] The leakage measurement was performed at 20 L / min, which was lower than the allowable 50 L / min.

[0167] 4. Assignment results:

[0168] 9 bridge plugs were successfully drilled without any increase in leakage

[0169] The liquid and oil production was restored to the highest level before the workover within 3 days after the workover.

[0170] Examples 6-7 all demonstrate the effectiveness of the present invention in different operations, especially in high loss environments, successfully reducing the loss volume and improving the operation efficiency. The rapid degradation characteristics of the temporary plugging fluid ensure that the permeability of the reservoir after the operation is not affected in the long term, significantly reducing the operation cost and shortening the operation cycle.

[0171] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a temporary plugging fluid for low-pressure and high-loss oil wells, characterized in that: The following steps are involved: Prepare pre-liquid: including emulsifier, polyacrylamide, sodium hydroxide and water; Prepare temporary plugging liquid: including bactericide, sodium hydroxide, xanthan gum or carboxymethyl starch, super absorbent resin, water-soluble elastic particles HJK series, water; Prepare the initiating solution: including sodium hydroxide, borax and water.

2. The preparation method according to claim 1, characterized in that: The components of the pre-fluid, temporary plugging fluid and initiating fluid of the temporary plugging fluid for low-pressure high leakage oil wells are as follows, calculated by weight percentage: The pre-fluid comprises, by weight percentage, 0.05% to 0.1% of emulsifier ABSN, 0.1% to 0.3% of polyacrylamide, 0.05% to 0.1% of sodium hydroxide, and the balance is water; The temporary plugging liquid comprises, by weight percentage, 0.05% to 0.1% of a bactericide, 0.1% to 0.3% of sodium hydroxide, 0.3% to 0.5% of xanthan gum or 1% to 1.5% of carboxymethyl starch, 0.3% to 0.5% of a highly absorbent resin, 1% to 10% of HJK ​​series water-soluble elastic particles, and the balance being water; The initiating liquid comprises, by weight percentage, 0.05% to 0.1% of sodium hydroxide, 0.1% to 0.5% of borax, and the balance is water.

3. The preparation method according to claim 2, characterized in that: The particle size of the super absorbent resin is 5 to 20 meshes.

4. The preparation method according to claim 1, characterized in that: The super absorbent resin is a dry agent, which is pre-absorbed and swollen before use and then added into the system to increase the temporary plugging effect.

5. The preparation method according to claim 1, characterized in that: The water-soluble elastic particles are added during on-site construction to fully absorb water and swell in the blasthole and the leakage channel, thereby further enhancing the temporary plugging effect.

6. An application method of a temporary plugging fluid for low-pressure and high-loss oil wells, comprising: using the temporary plugging fluid for low-pressure and high-loss oil wells prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Close the oil well blowout preventer and tubing cock, and squeeze 20 to 30 cubic meters of pre-fluid from the casing valve into the wellbore in the reverse direction; S2. Squeeze temporary plugging fluid in reverse from the casing valve at a displacement of 350L / s to 400L / s until the wellhead pressure rises to above 10MPa; S3, squeeze 10 to 20 cubic meters of initiating liquid in the reverse direction from the casing valve at a displacement of 350L / s to 400L / s; S4. Squeeze the displacement fluid in reverse from the casing valve at a displacement rate of 350L / s to 450L / s. The volume of the displacement fluid is determined according to the wellbore volume. S5. After sufficient displacement fluid is injected, the wellbore is pressurized for 20 to 40 minutes; S6. Open the well to drain the fluid, measure the loss, and after confirming that the loss requirements are met, proceed with sand flushing, plug drilling and scale drilling operations.

7. The application method according to claim 6, characterized in that: The size of the water-soluble elastic particles in the temporary plugging fluid is adjusted according to the well conditions. In conventional perforation sections, particles of 10 mm to 15 mm are used, and in hydraulic sandblasting perforation sections, particles of 1 mm to 10 mm are used.

8. The application method according to claim 6, characterized in that: After the extrusion pressure of the temporary plugging fluid rises to above 10 MPa, the pressure is maintained for at least 5 minutes to ensure that the temporary plugging fluid is fully distributed in the wellbore.

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