阅读说明：本技术 一种大段套损井补强密封修复方法 (Reinforcing, sealing and repairing method for large-section casing damage well ) 是由 杨立华 周志平 郭钢 李琼玮 孙雨来 谷成义 王小勇 卢文伟 付彩利 程碧海 于 2020-11-04 设计创作，主要内容包括：本发明属于油田技术领域,具体提供了一种大段套损井补强密封修复方法,连续油管通过打压接头连接高压软管,并由连续油管将高压软管下至套破层段,所述高压软管下入前在外表面均匀涂敷热熔胶；然后通过连续油管向高压软管内挤注水蒸气,使高压软管外表面温度升高至设定温度且高压软管恢复圆度,高压软管外表面的热熔胶熔化后使套管内壁与高压软管粘结；解决了套管内壁腐蚀严重套损井,金属膨胀管补贴、机械隔采施工难度大,成功率低,有效期短的问题,本发明可实现一次整体下入连续补贴修复管材,提高作业效率,修复管材打压膨胀后,通过管外高强度补强修复材料粘贴在套管内壁,实现永久修复的方法。(The invention belongs to the technical field of oil fields, and particularly provides a large-section casing damage well reinforcing, sealing and repairing method.A continuous oil pipe is connected with a high-pressure hose through a pressurizing connector, the high-pressure hose is lowered to a casing damage layer section through the continuous oil pipe, and the outer surface of the high-pressure hose is uniformly coated with hot melt adhesive before the high-pressure hose is lowered; then, water vapor is extruded into the high-pressure hose through the continuous oil pipe, so that the temperature of the outer surface of the high-pressure hose is raised to a set temperature, the roundness of the high-pressure hose is recovered, and the inner wall of the sleeve is bonded with the high-pressure hose after the hot melt adhesive on the outer surface of the high-pressure hose is melted; the method solves the problems of serious corrosion of the inner wall of the casing, casing damage of a well, high repairing difficulty of a metal expansion pipe and mechanical isolation construction, low success rate and short effective period.)

1. A reinforcing, sealing and repairing method for a large-section casing damage well is characterized by comprising the following steps: the method comprises the following steps:

1) a bridge plug (2) is arranged below the casing fracture layer section (1), and the bridge plug (2) is set and tested;

2) setting the oil pipe with a packer to a position above the fractured layer section (1), and after clear water is squeezed into the oil pipe to verify the fractured layer section (1) and the water absorption capacity of the fractured layer section, pulling out the oil pipe and the packer;

3) the continuous oil pipe (5) is connected with the high-pressure hose (4) through the pressing joint (3), the high-pressure hose (4) is lowered to the casing-broken layer section (1) through the continuous oil pipe (5), and the outer surface of the high-pressure hose (4) is uniformly coated with hot melt adhesive (6) before the high-pressure hose is lowered; then, water vapor is squeezed into the high-pressure hose (4) through the continuous oil pipe (5), so that the temperature of the outer surface of the high-pressure hose (4) is raised to a set temperature, the roundness of the high-pressure hose (4) is recovered, and the inner wall of the sleeve is bonded with the high-pressure hose (4) after the hot melt adhesive (6) on the outer surface of the high-pressure hose (4) is melted;

4) after the bonding is finished, after the hot melt adhesive (6) is solidified, the coiled tubing (5) is lifted up, the pressurizing connector (3) is disconnected from the high-pressure hose (4), the pressurizing connector (3) is lifted up, and after the pressure test of the casing pipe is qualified, the casing pipe is pumped down for well completion.

2. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the thickness of the hot melt adhesive (6) coated in the step 3) is 5-10 mm.

3. The method for repairing the seal of the large casing damage well according to claim 1, wherein: before the step 3) is put into the device, the high-pressure hose (4) below the pressing joint (3) is pressed into a U shape.

4. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the high-pressure hose (4) is a fiber reinforced polyurethane hose.

5. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the hot melt adhesive (6) is a copolyester hot melt adhesive.

6. The method for repairing the seal of the large casing damage well according to claim 5, wherein: the copolyester hot melt adhesive is prepared by combining terephthalic acid, 1, 4-butanediol, dimethyl phthalate, tetra-n-butyl titanate, dimer acid and hydrogenated liquid polybutadiene dihydric alcohol, wherein the mass ratio of the terephthalic acid, the 1, 4-butanediol, the dimethyl phthalate, the tetra-n-butyl titanate, the dimer acid and the hydrogenated liquid polybutadiene dihydric alcohol is 30:120-150:10-12:0.01-0.03:15-30: 8-15.

7. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the high-pressure hose (4) is coiled and continuously fed in.

8. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the temperature of the outer surface of the high-pressure hose (4) in the step 3) is increased to 80 ℃.

9. The method for repairing the seal of the large casing damage well according to claim 1, wherein: the bridge plug is put into a position 50m below the casing fracture layer section (1) in the step 1); and step 2) setting the oil pipe with the packer to a position 10m above the casing fracture layer section (1).

Technical Field

The invention belongs to the technical field of oil fields, and particularly relates to a method for repairing a large-section casing damage well through reinforcement and sealing.

Background

The oil well stratum output liquid corrodes the inner wall of the casing pipe to cause hundreds of meters of perforation and pit corrosion damage, and is influenced by scaling and pit corrosion of the inner wall of the shaft, the conventional metal expansion pipe and sealing rubber ring patching repair adopts a plurality of expansion pipe screw threads to connect, the expansion patching is completed by upward expansion of a metal expansion cone, the underground operation process is complex, the drilling risk is large, the material cost is high, and the expansion pipe screw threads and the sealing of the rubber ring outside the pipe are easy to lose efficacy. At present, mechanical packers are mainly used for isolating production of the wells, and effective setting sections are difficult to find by mechanical isolation along with further corrosion of a shaft.

Aiming at a well with serious casing damage caused by corrosion of the inner wall of the casing, the construction difficulty of patching and mechanical isolation of the metal expansion pipe is high, the success rate is low, and the effective period is short. The large-section shaft overall repair reinforced pipe needs to be adopted to realize one-time operation repair, and the repair of the reinforced sealing between the pipe and the inner wall of the sleeve requires the adoption of a reinforced sealing material which can be extruded and has high strength after being cured. So as to improve the compression strength and the sealing validity period of the repaired casing.

Disclosure of Invention

The invention provides a reinforcing, sealing and repairing method for a large-section casing damage well, and aims to solve the problems that in the prior art, a mechanical packer is adopted for production isolation aiming at a casing damage well with serious corrosion on the inner wall of a casing, the underground operation process is complex, the drilling risk is high, the material cost is high, the thread of an expansion pipe and the sealing of an outer rubber ring are easy to lose efficacy, and an effective seat sealing section is difficult to find for mechanical isolation mining along with further corrosion of a shaft.

Therefore, the invention provides a method for repairing a large-section casing damage well by reinforcing and sealing, which comprises the following steps:

1) a bridge plug is arranged below the casing layer section, and the bridge plug is sealed and tested;

2) setting the oil pipe with a packer to a position above the casing fracture section, extruding clear water into the oil pipe to verify the casing fracture section and the water absorption capacity of the casing fracture section, and then taking out the oil pipe and the packer;

3) the coiled tubing is connected with the high-pressure hose through a pressing joint, the high-pressure hose is lowered to the casing fracture layer section through the coiled tubing, and the outer surface of the high-pressure hose is uniformly coated with hot melt adhesive before the high-pressure hose is lowered; then, water vapor is extruded into the high-pressure hose through the continuous oil pipe, so that the temperature of the outer surface of the high-pressure hose is raised to a set temperature, the roundness of the high-pressure hose is recovered, and the inner wall of the sleeve is bonded with the high-pressure hose after the hot melt adhesive on the outer surface of the high-pressure hose is melted;

4) after the bonding is finished and the hot melt adhesive is solidified, the coiled tubing is lifted up to disconnect the pressurizing connector and the high-pressure hose, the pressurizing connector is lifted up, and the casing is pumped down for well completion after the clean water pressure test of the casing is qualified.

The thickness of the hot melt adhesive coated in the step 3) is 5-10 mm.

And 3) before the step 3) is performed, pressing the high-pressure hose below the pressing joint into a U shape.

The high-pressure hose is a fiber reinforced polyurethane hose.

The hot melt adhesive is a copolyester hot melt adhesive.

The copolyester hot melt adhesive is prepared by combining terephthalic acid, 1, 4-butanediol, dimethyl phthalate, tetra-n-butyl titanate, dimer acid and hydrogenated liquid polybutadiene dihydric alcohol, wherein the mass ratio of the terephthalic acid, the 1, 4-butanediol, the dimethyl phthalate, the tetra-n-butyl titanate, the dimer acid and the hydrogenated liquid polybutadiene dihydric alcohol is 30:120-150:10-12:0.01-0.03:15-30: 8-15.

The high pressure hose is coiled and continuously lowered.

The temperature of the outer surface of the high-pressure hose is increased to 80 ℃ in the step 3).

The bridge plug in the step 1) is put 50m below the casing fracture layer section; and 2) setting the oil pipe with the packer to a position 10m above the casing fracture section.

The invention has the beneficial effects that: the invention provides a method for strengthening, sealing and repairing a large-section damaged well, which comprises the steps of putting a whole section of repairing pipe (high-pressure hose) with the outer surface coated with thermosol to a damaged layer section at one time during the strengthening and repairing of a large-section internal corrosion damaged well, then injecting water vapor into the high-pressure hose through a continuous oil pipe to ensure that the temperature of the outer surface of the high-pressure hose is raised to a set temperature and the high-pressure hose recovers the roundness, bonding the inner wall of a sleeve with the high-pressure hose after melting of the thermosol on the outer surface of the high-pressure hose so that the outer surface of the high-pressure hose is firmly adhered to the inner surface of the sleeve, enabling thermosol resin to enter pit-shaped corrosion points and perforation points of the sleeve at high temperature to realize plugging and sealing, forming a high-strength adhesion sealing layer between the inner surface of the sleeve and the outer surface of the high-pressure hose, permanent repair of large-section casing damage is realized; the underground operation process is simple, the sealing is not easy to lose effectiveness, and the whole section of repaired pipe can be effectively sealed no matter how serious the shaft is corroded.

Drawings

The present invention will be described in further detail below with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of the principle of a large-section casing damage well reinforcing and sealing repairing method.

Description of reference numerals: 1. a cased-hole segment; 2. a bridge plug; 3. pressing the joint; 4. a high pressure hose; 5. a coiled tubing; 6. hot melt adhesive; 7. a gauge pipe; 8. producing a sleeve; 9. an oil interval section; 10. and (5) artificial well bottom.

Detailed Description

Example 1:

as shown in fig. 1, a method for repairing a large-section damaged casing well by reinforcing and sealing comprises the following steps:

1) a bridge plug 2 is arranged below the casing layer section 1, and the bridge plug 2 is seated and tested;

2) setting the oil pipe with a packer to a position above the casing fracture section 1, squeezing clear water into the oil pipe to verify the casing fracture section 1 and the water absorption capacity of the casing fracture section, and then taking out the oil pipe and the packer;

3) the continuous oil pipe 5 is connected with the high-pressure hose 4 through the pressing joint 3, the high-pressure hose 4 is lowered to the casing fracture layer section 1 through the continuous oil pipe 5, and the outer surface of the high-pressure hose 4 is uniformly coated with hot melt adhesive 6 before the high-pressure hose 4 is lowered; then, water vapor is squeezed into the high-pressure hose 4 through the continuous oil pipe 5, so that the temperature of the outer surface of the high-pressure hose 4 is raised to a set temperature, the roundness of the high-pressure hose 4 is recovered, and the inner wall of the sleeve is bonded with the high-pressure hose 4 after the hot melt adhesive 6 on the outer surface of the high-pressure hose 4 is melted;

4) after the bonding is finished, after the hot melt adhesive 6 is solidified, the continuous oil pipe 5 is lifted up, the pressurizing connector 3 is disconnected from the high-pressure hose 4, the pressurizing connector 3 is lifted up, and after the sleeve is qualified in pressure test by clear water, the pump is put down for well completion.

When the corrosion casing damage well in the large section is reinforced and repaired, a high-pressure hose with the outer surface coated with thermosol 6 is put down to the casing damage layer section at one time, then water vapor is extruded into the high-pressure hose 4 through the continuous oil pipe 5, the temperature of the outer surface of the high-pressure hose 4 is raised to a set temperature, the roundness of the high-pressure hose 4 is recovered, the inner wall of the sleeve is bonded with the high-pressure hose 4 after the thermosol 6 on the outer surface of the high-pressure hose 4 is melted, the outer surface of the high-pressure hose 4 is firmly adhered to the inner surface of the sleeve, the thermosol 6 enters the pit-shaped corrosion points and the perforation points of the sleeve at high temperature to realize plugging and sealing, and a high-strength adhesive sealing layer is formed between the inner surface of the sleeve and the outer surface of the high-pressure hose after cooling and solidification, so that casing; the underground operation process is simple, the sealing is not easy to lose effectiveness, and no matter how serious the shaft is corroded, the high-pressure hose can be effectively sealed for the whole section of repaired pipe.

Example 2:

further, the thickness of the hot melt adhesive 6 coated in the step 3) is 5-10 mm. The thickness of 5-10mm ensures that the outer surface of the high-pressure hose 4 can be firmly adhered to the inner surface of the sleeve, the thermosol 6 can enter pit-shaped corrosion points and perforation points of the sleeve at high temperature to realize plugging and sealing, and a high-strength adhesive sealing layer is formed between the inner surface of the sleeve and the outer surface of the high-pressure hose after cooling and solidification, so that the plugging of the damaged sleeve and the perforation can be realized, the integral reinforcement of a perforated casing damage section can be realized, the compressive strength of the whole section of the sleeve is improved, and the permanent repair of large section of casing damage is.

Further, the hot melt adhesive 6 is a copolyester hot melt adhesive. The copolyester hot melt adhesive has high bonding strength, good impact resistance, high melting point, heat resistance and good chemical resistance.

Furthermore, the copolyester hot melt adhesive is prepared by combining terephthalic acid, 1, 4-butanediol, dimethyl phthalate, tetra-n-butyl titanate, dimer acid and hydrogenated liquid polybutadiene diol, wherein the mass ratio of the terephthalic acid, the 1, 4-butanediol, the dimethyl phthalate, the tetra-n-butyl titanate, the dimer acid and the hydrogenated liquid polybutadiene diol is 30:120-150:10-12:0.01-0.03:15-30: 8-15. The preparation and synthesis method of the copolyester hot melt adhesive is a synthesis method of a conventional hot melt adhesive, and is not described in detail herein; the viscosity of the copolyester hot melt adhesive liquid at normal temperature is 800-1000mPa & s, the copolyester hot melt adhesive is a soft viscous solid within the range of normal temperature to 65 ℃, is not miscible with water, can be heated at 80 ℃ for crosslinking and curing at fixed time, and the bonding strength of a cured body is more than 15 MPa.

Example 3:

on the basis of the embodiment 2, further, before the step 3) is started, the high-pressure hose 4 below the pressing joint 3 is pressed into a U shape. The high-pressure hose 4 below the pressurizing joint is pressed into a U shape so as to be convenient for entering a well, and the high-pressure hose is prevented from being longitudinally folded.

Further, the high-pressure hose 4 is a fiber-reinforced polyurethane hose. The hose can be pressed and molded at normal temperature, the maximum outer diameter is reduced to 4 inches and a half, a half shaft with 5 inches can be conveniently put in, the longitudinal structure is stable in the process of putting in the shaft, and the hose is not bent and deformed; the hose can be restored to the original external diameter size of 124.5mm under the condition of 30-80 ℃ and the internal pressure of 10 MPa.

Further, the high pressure hose 4 is wound and continuously fed. The high-pressure hose 4 can be coiled in a large section and continuously put in, and can be pressurized and heated once after being put in, so that the once reinforcing, sealing and repairing of the large-section casing damage well are realized, and the compressive strength of the casing damage section is improved.

Further, the temperature of the outer surface of the high pressure hose 4 is increased to 80 ℃ in the step 3). The temperature of the outer surface of the high-pressure hose 4 is raised to 80 ℃, so that the hot melt adhesive can be heated, crosslinked and solidified at the temperature of 80 ℃ at fixed time, and the bonding strength of a solidified body is more than 15 MPa.

Further, the bridge plug in the step 1) is put into a position 50m below the casing fracture layer 1; and step 2), setting the oil pipe with the packer to a position 10m above the casing fracture section 1. The complete and firm sealing of the sleeve breaking layer section is ensured.

Further, the bridge plug is a drillable bridge plug; the packer is an insert pipe type packer; the bridge plug can separate the oil layer section 9 from the sleeve breaking point, and compared with a removable packer which cannot work for a long time and needs to be unsealed when an oil (water) well is overhauled, the packer is put in again after the overhaul is finished, and time and labor are wasted; the inserted tube type packer overhauling oil (water) well only needs to extract the inserted tube of the packer, and the packer is inserted after overhauling, the packer is always left at the bottom of the well without deblocking, the service life of the inserted tube type permanent packer can reach 3-5 a when the inserted tube type permanent packer is used conventionally, and sometimes can reach more than ten years.

Example 3:

z192-108 well

The well is put into production in 7 months in 2013, the production position Y9, the perforation section 2082-³5.6t of daily oil production, 21 percent of water content and 72635mg/L of salt, 1382m of working fluid surface, 5 months in 2018, the water content is increased to 100 percent, and 7100mg/L of salt is contained. MTT + MIT engineering logging in 7 months in 2018 shows that a large section of corrosion perforation exists in the position 1586-1861m of the casing.

And (3) reinforcing and repairing by adopting a high-pressure hose and copolyester hot melt adhesive.

The construction steps are as follows:

1) pulling out the original well pipe column, and drifting with a drift diameter of 118mm multiplied by 1.5m to the bottom 10 of the artificial well; setting and checking the sealing of the fishable bridge plug when the fishable bridge plug is positioned to 2030 m;

2) setting the packer to a position (1576m) 10m above the sleeve breaking point, sealing, extruding and injecting clear water for 3 directions, discharging at a discharge capacity of 50L/min-150L/min, verifying the sleeve breaking point and the water absorption capacity thereof, and pulling out the packer and the pipe column; the sleeve breaking point is positioned on the production sleeve 8, and the production sleeve 8 is sleeved in the gauge pipe 7;

3) the continuous oil pipe 5 is connected with a high-pressure hose 4 through a pressing joint 3, and the outer surface of the high-pressure hose is coated with 5mm copolyester hot melt adhesive; putting a high-pressure composite hose 525 meters (the well depth is 1500m-2025 m); the ground pump truck injects high-pressure (10MPa) water vapor into the high-pressure hose for 15 minutes through the continuous oil pipe, so that the temperature of the outer surface of the high-pressure hose is raised to 80 ℃ and the roundness is recovered, and the inner wall of the sleeve is firmly bonded with the high-pressure hose after hot sol is coated and melted outside the high-pressure hose;

4) stopping injecting, pressurizing and injecting water vapor, lifting the oil pipe after the hot melt adhesive is cooled and solidified for 1 hour, and pulling the breaking hose to be connected with the pressurizing connector to lift the pressurizing connector. Testing the pressure by clean water for 15MPa, and discharging the pump to complete the well if the pressure drop is less than 0.5MPa after 30 min.

The hot melt adhesive 6 is prepared by combining terephthalic acid, 1, 4-butanediol, dimethyl phthalate, tetra-n-butyl titanate, dimer acid and hydrogenated liquid polybutadiene dihydric alcohol, wherein the mass ratio of the terephthalic acid, the 1, 4-butanediol, the dimethyl phthalate, the tetra-n-butyl titanate, the dimer acid and the hydrogenated liquid polybutadiene dihydric alcohol is 30:135:11:0.02:22: 11.

After the corroded perforated section of the well casing is reinforced and repaired, the bearing capacity of the shaft is recovered to 15MPa, and the daily produced fluid is 5.8m after treatment³4.1t of daily oil, 32.6 percent of water.

In the description of the present invention, it is to be understood that the terms "front", "inside", "right", and the like, if any, are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are used for illustrative purposes only and are not to be construed as limiting the present patent.

The above examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims and any design similar or equivalent to the scope of the invention.