A novel staged fracturing temporary plugging ball for fracturing acidizing

Abstract

The present invention relates to the technical field of novel temporary plugging balls, and discloses a novel staged fracturing temporary plugging ball for fracturing acidification, which comprises a spherical ball. A through hole is formed through the center of the spherical ball. A rope is arranged at the left end of the spherical ball. The right end face of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball. Both ends of the rope are knotted, and the temporary plugging ball is clamped at the center of the two knots; The spherical ball of the novel temporary plugging ball comprises the following raw materials in parts by weight: 80 parts - 90 parts of main material; 5 parts - 10 parts of rigid material; 0.5 parts - 1 part of plasticizer. The end of the rope is unfolded to form a tassel shape, which forms a design of guiding tassels for the temporary plugging ball, so as to enhance its ability to sense the fluid direction at the crack and increase the diversion ability. During plugging, the diversion effect of the tassel synergistically anchors the temporary plugging ball to the crack opening with the temporary plugging ball, and then the knot is tightened to block the central hole of the temporary plugging ball, forming a reliable plugging; After being put in, it flows with the fracturing fluid in the wellbore. Compared with the traditional temporary plugging ball, the plugging efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of novel temporary plugging balls, and particularly to a novel staged fracturing temporary plugging ball for fracturing acidification. Background Art

[0002] Fracturing acidification, abbreviated as acid fracturing, is a process of using acid fluid as the fracturing fluid under a pressure higher than the formation fracture pressure to perform fracturing without proppant. The temporary plugging ball for fracturing acidification is carried into the wellbore by the working fluid during construction, and preferentially plugs the perforation holes of the high-permeability layer under the action of pressure difference, forcing the working fluid to turn to the medium and low-permeability layers for transformation. After the construction is completed, it hydrolyzes into a water-soluble mixture and is discharged together with other liquids, so as to achieve a clean transformation of the formation, realize physical stratification transformation in the vertical direction, and at the same time reduce the risk of blockage in the surface process. It can be used in both the testing and completion stages. Its specifications are a diameter of 5 - 28 mm, and the density of various diameters ranges from 1.0 - 1.5 g / cm 3 , with a maximum differential pressure resistance of 90 MPa, a maximum temperature resistance of 150 °C, an adjustable dissolution time, and can meet the liquid drainage requirements at different times on site. The construction success rate is 100%, and it has the characteristics of simple construction, good temporary plugging performance, fast degradation speed, and high construction success rate.

[0003] Currently, most of the existing temporary plugging balls for fracturing acidification are water-insoluble balls, resulting in the continued retention of the temporary plugging balls in the casing after the profile control process, which brings inconvenience to subsequent construction and increases the process difficulty. Therefore, a novel staged fracturing temporary plugging ball for fracturing acidification is proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a novel staged fracturing temporary plugging ball for fracturing acidification to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A novel staged fracturing temporary plugging ball for fracturing acidification, including a spherical ball, a through hole is formed through the center of the spherical ball, a rope is arranged at the left end of the spherical ball, the right end surface of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball, and both ends of the rope are knotted to clamp the temporary plugging ball at the center of the two knots;

[0006] The spherical ball of the novel temporary plugging ball comprises raw materials with the following weight part ratios:

[0007] 80 - 90 parts of main material;

[0008] 5 - 10 parts of rigid material;

[0009] 0.5 - 1 part of plasticizer.

[0010] Preferably, the main material of the spherical ball is one or a combination of several of PVA0388, PVA0588, PVA0988, PGA, and PLA.

[0011] Preferably, the rope material is selected from soluble or degradable fibers such as PVA, PLA, and PGA.

[0012] A new type of staged fracturing temporary plugging ball for fracturing acidification, and a manufacturing method for the new temporary plugging ball:

[0013] It includes the following steps:

[0014] S1. Use one or a combination of several of PVA0388, PVA0588, PVA0988, PGA, and PLA as the main material, and the dosage of the main material is 80 parts - 90 parts;

[0015] S2. Crush the main material, place it at a temperature of 200°C - 250°C for mixing, heat and melt it, introduce high-purity nitrogen, stir evenly, then heat to 230°C - 260°C, add a catalyst solution, and react for 2 - 24 hours;

[0016] S3. Add 5 parts - 10 parts of rigid material to the melted main material;

[0017] S4. Then add 0.5 parts - 1 part of plasticizer, mix evenly under a temperature condition above 280°C, add a non-ionic surfactant and mix evenly, and stop heating;

[0018] S5. Use an injection molding process to process into regular spherical balls;

[0019] S6. Then polish the surface of the spherical ball;

[0020] S7. According to the thickness requirement, select 4 / 8 / 16 / 24 strands to be stranded into a thin rope, first tie a knot at one time for one or more stranded thin ropes, and then tie a knot again on the unknotted side, so that the whole knot is stuck in the center of the sphere;

[0021] S8. Finally, unfold the end of the rope to form a tassel shape.

[0022] Preferably, in step 1, one or a combination of several is used as the main material according to the dissolution time and pressure-bearing capacity required in actual situations.

[0023] Preferably, the rigid material in step 3 is calcium carbonate.

[0024] Preferably, the plasticizer in step 4 mainly uses dibutyl sebacate or dibutyl adipate or dibutyl phthalate.

[0025] Preferably, the non-ionic surfactant in step 4 includes one or a combination of polyoxyethylene fatty amide, polyoxyethyl alkyl ether, polyoxyethylene alkyl amide, and fatty alcohol polyoxyethylene ether.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. For the novel sectional fracturing temporary plugging ball used in fracturing acidification, the end of the rope unfolds to form a tassel shape. The design of forming a guiding tassel for the temporary plugging ball enables its perception ability of the fluid direction at the fracture, increases the diversion ability, and the diversion effect of the tassel during plugging synergistically anchors the temporary plugging ball to the fracture opening. Subsequently, the rope knot is tightened to block the central hole of the temporary plugging ball, forming a reliable plugging.

[0028] 2. For the novel sectional fracturing temporary plugging ball used in fracturing acidification, after being put in, it flows in the wellbore with the fracturing fluid. Compared with the traditional temporary plugging ball, the plugging efficiency is greatly improved; there are many choices for the main material type of the temporary plugging ball, which can be applicable to different types of fracturing acidification. The finally prepared temporary plugging ball has the performance advantages of being soluble, high-strength, and adjustable density.

[0029] 3. For the novel sectional fracturing temporary plugging ball used in fracturing acidification, when it is applied to selective fracturing of a fractured well, it is simple and convenient, and the effect is obvious. It can effectively solve the problem of excessive pressure loss during repeated fracturing of old wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a physical diagram of the product of the present invention;

[0031] Figure 2 It is a structural diagram of the sphere of the present invention;

[0032] Figure 3 It is a structural diagram of the rope knot of the present invention;

[0033] Figure 4 It is a schematic cross-sectional view of the temporary plugging ball of the present invention;

[0034] Figure 5 It is a schematic plugging diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] Please refer to Figures 1 - 5 , the present invention provides the following technical solutions:

[0037] Example 1:

[0038] A new type of staged fracturing temporary plugging ball for fracturing acidification, including a spherical ball. A through hole is drilled through the center of the spherical ball. A rope is arranged at the left end of the spherical ball. The right end face of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball. The two ends of the rope are knotted, and the temporary plugging ball is stuck at the center of the two knots. The material of the rope is selected as PVA;

[0039] The spherical ball of the new type of temporary plugging ball includes raw materials with the following weight parts ratio:

[0040] 90 parts of main material. The main material of the spherical ball is PVA0388;

[0041] 5 parts of rigid material;

[0042] 1 part of plasticizer.

[0043] A new type of staged fracturing temporary plugging ball for fracturing acidification, manufacturing method of the new type of temporary plugging ball:

[0044] Including the following steps:

[0045] S1. According to the actual required dissolution time and pressure-bearing capacity, use PVA0388 as the main material, and the dosage of the main material is 90 parts;

[0046] S2. Crush the main material, place it at a temperature of 250 °C for mixing, heat and melt it, introduce high-purity nitrogen, stir evenly, then heat to 260 °C, add a catalyst solution, and react for 24 h;

[0047] S3. Add 5 parts of rigid material to the melted main material. The rigid material is calcium carbonate;

[0048] S4. Then add 1 part of plasticizer. The plasticizer mainly uses dibutyl sebacate, mix evenly under a temperature condition of more than 280 °C, then add a non-ionic surfactant and mix evenly, and stop heating. The non-ionic surfactant is polyoxyethylene fatty amide;

[0049] S5. Use an injection molding process to process into a regular spherical ball;

[0050] S6. Then polish the surface of the spherical ball;

[0051] S7. According to the thickness requirement, select 24 strands to be combined into a thin rope, first tie a knot once for the multiple combined thin ropes, and then tie a knot again for the unknotted side, so that the whole knot is stuck at the center of the sphere;

[0052] S8. Finally, unfold the end of the rope to form a tassel shape.

[0053] Example two:

[0054] A novel staged fracturing temporary plugging ball for fracturing acidification, including a spherical ball. A through hole is drilled through the center of the spherical ball. A rope is arranged at the left end of the spherical ball. The right end face of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball. Both ends of the rope are knotted, and the temporary plugging ball is stuck at the center of the two knots. The material of the rope is selected as PVA;

[0055] The spherical ball of the novel temporary plugging ball includes raw materials with the following mass percentages:

[0056] 85 parts of main material. The main material of the spherical ball is PVA0588;

[0057] 8 parts of rigid material;

[0058] 0.8 parts of plasticizer.

[0059] A novel staged fracturing temporary plugging ball for fracturing acidification. The manufacturing method of the novel temporary plugging ball:

[0060] Includes the following steps:

[0061] S1. According to the actual required dissolution time and pressure-bearing capacity, PVA0588 is used as the main material, and the dosage of the main material is 85 parts;

[0062] S2. Crush the main material, place it at a temperature of 230 °C for mixing, heat it to melt, introduce high-purity nitrogen, stir evenly, then heat it to 250 °C, add the catalyst solution, and react for 18 h;

[0063] S3. Add 8 parts of rigid material to the melted main material. The rigid material is calcium carbonate;

[0064] S4. Then add 0.8 parts of plasticizer. The plasticizer mainly uses dibutyl sebacate, mix evenly under the temperature condition above 280 °C, then add non-ionic surfactant and mix evenly, and stop heating. The non-ionic surfactant is polyoxyethylene fatty amide;

[0065] S5. Use the injection molding process to process into regular spherical balls;

[0066] S6. Then polish the surface of the spherical ball;

[0067] S7. According to the thickness requirement, select 16 strands to be combined into a thin rope, first tie a knot in one go for the multiple combined thin ropes, and then tie a knot again on the unknotted side, so that the whole knot is stuck at the center of the sphere;

[0068] S8. Finally, unfold the end of the rope to form a tassel shape.

[0069] Example 3:

[0070] A new type of staged fracturing temporary plugging ball for fracturing acidification, comprising a sphere, a through hole is opened through the center of the sphere, a rope is arranged at the left end of the sphere, the right end face of the rope penetrates the surface of the sphere and the inner wall of the through hole and extends to the right side of the sphere, the two ends of the rope are knotted, and the temporary plugging ball is clamped in the center of the two knots, and the rope material is selected from PVA;

[0071] The new temporary plugging ball comprises the following raw materials in proportion by weight:

[0072] 80 parts of main materials, the main materials of the balls are PVA0588 and PVA0988;

[0073] 10 rigid materials;

[0074] 1 part plasticizer.

[0075] A new type of temporary plugging ball for staged fracturing and acidizing, and a method for making the new type of temporary plugging ball:

[0076] The following steps are involved:

[0077] S1. According to the actual dissolution time and pressure bearing capacity required, PVA0588 and PVA0988 are used as the main materials, and the amount of the main materials is 80 parts;

[0078] S2, crush the main material, place it at a temperature of 220°C for mixing, heat it to melt, introduce high-purity nitrogen, stir it evenly, then heat it to 240°C, add the catalyst solution, and react for 19 hours;

[0079] S3, adding 10 parts of rigid material to the melted main material, the rigid material is calcium carbonate;

[0080] S4, add 1 part of plasticizer, the plasticizer is mainly dibutyl sebacate, mix evenly at a temperature above 280°C, then add non-ionic surfactant and mix evenly, stop heating, the non-ionic surfactant is polyoxyethylene fatty amide;

[0081] S5, processed into regular spheres by injection molding;

[0082] S6, polishing the surface of the sphere;

[0083] S7. According to the thickness requirement, choose to combine 8 strands into a thin rope, tie a knot on each strand of the thin rope, and then tie another knot on the untied side, so that the entire knot is stuck in the center of the sphere;

[0084] S8. Finally, unfold the end of the rope to form a tassel shape.

[0085] Embodiment 4:

[0086] A new type of staged fracturing temporary plugging ball for fracturing acidification, comprising a spherical ball, a through hole is opened through the center of the spherical ball, a rope is arranged at the left end of the spherical ball, the right end face of the rope penetrates the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball, the two ends of the rope are knotted, and the temporary plugging ball is clamped in the center of the two knots, and the rope material is selected from PGA;

[0087] The new temporary plugging ball comprises the following raw materials in proportion by weight:

[0088] 90 parts of main materials, the main materials of the ball are PVA0988 and PGA;

[0089] 6 rigid materials;

[0090] 0.6 parts of plasticizer.

[0091] A new type of temporary plugging ball for staged fracturing and acidizing, and a method for making the new type of temporary plugging ball:

[0092] The following steps are involved:

[0093] S1. According to the actual dissolution time and pressure bearing capacity required, PVA0988 and PGA are used as the main materials, and the amount of the main materials is 90 parts;

[0094] S2, crush the main material, place it at a temperature of 200°C for mixing, heat it to melt, introduce high-purity nitrogen, stir it evenly, then heat it to 230°C, add the catalyst solution, and react for 16 hours;

[0095] S3, adding 6 parts of rigid material to the melted main material, the rigid material is calcium carbonate;

[0096] S4, add 0.6 parts of plasticizer, the plasticizer is mainly dibutyl sebacate, mix evenly at a temperature above 280°C, then add non-ionic surfactant and mix evenly, stop heating, the non-ionic surfactant is polyoxyethylene fatty amide;

[0097] S5, processed into regular spheres by injection molding;

[0098] S6, polishing the surface of the sphere;

[0099] S7. According to the thickness requirement, choose to use 4 strands to make a thin rope, tie a knot on each strand of the thin rope, and then tie another knot on the untied side, so that the whole knot is stuck in the center of the sphere;

[0100] S8. Finally, unfold the end of the rope to form a tassel shape.

[0101] Embodiment five:

[0102] A novel staged fracturing temporary plugging ball for fracturing acidification, comprising a spherical ball. A through hole is formed through the center of the spherical ball. A rope is arranged at the left end of the spherical ball. The right end face of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball. Both ends of the rope are knotted, and the temporary plugging ball is stuck at the center of the two knots. The material of the rope is selected as PVA;

[0103] The spherical ball of the novel temporary plugging ball comprises raw materials with the following weight parts ratio:

[0104] 90 parts of main material. The main material of the spherical ball is PVA0988 and PLA;

[0105] 5 parts of rigid material;

[0106] 1 part of plasticizer.

[0107] A novel staged fracturing temporary plugging ball for fracturing acidification. The manufacturing method of the novel temporary plugging ball:

[0108] Comprises the following steps:

[0109] S1. According to the actual required dissolution time and pressure-bearing capacity, use PVA0988 and PLA as the main materials, and the dosage of the main materials is 90 parts;

[0110] S2. Crush the main materials, place them at a temperature of 210°C for mixing, heat and melt them, introduce high-purity nitrogen, stir evenly, then heat to 250°C, add a catalyst solution, and react for 20 h;

[0111] S3. Add 5 parts of rigid material to the melted main materials. The rigid material is calcium carbonate;

[0112] S4. Then add 1 part of plasticizer. The plasticizer mainly uses dibutyl sebacate, mix evenly under the temperature condition above 280°C, then add a non-ionic surfactant and mix evenly, and stop heating. The non-ionic surfactant is polyoxyethylene fatty amide;

[0113] S5. Use an injection molding process to process into a regular spherical ball;

[0114] S6. Then polish the surface of the spherical ball;

[0115] S7. According to the thickness requirement, select 8 strands to be combined into a thin rope. First, tie a knot for the multiple combined thin ropes at one time, and then tie a knot again for the unknotted side, so that the whole knot is stuck at the center of the sphere;

[0116] S8. Finally, unfold the end of the rope to form a tassel shape.

[0117] Example six:

[0118] A new type of staged fracturing temporary plugging ball for fracturing acidification, comprising a sphere, a through hole is opened through the center of the sphere, a rope is arranged at the left end of the sphere, the right end face of the rope penetrates the surface of the sphere and the inner wall of the through hole and extends to the right side of the sphere, the two ends of the rope are knotted, and the temporary plugging ball is clamped in the center of the two knots, and the rope material is selected from PVA;

[0119] The new temporary plugging ball comprises the following raw materials in proportion by weight:

[0120] 90 parts of main materials, the main materials of the balls are PVA0388 and PVA0988;

[0121] 8 rigid materials;

[0122] 0.7 parts of plasticizer.

[0123] A new type of temporary plugging ball for staged fracturing and acidizing, and a method for making the new type of temporary plugging ball:

[0124] The following steps are involved:

[0125] S1. According to the actual dissolution time and pressure bearing capacity required, PVA0388 and PVA0988 are used as the main materials, and the amount of the main materials is 90 parts;

[0126] S2, crush the main material, place it at a temperature of 200°C for mixing, heat it to melt, introduce high-purity nitrogen, stir it evenly, then heat it to 260°C, add the catalyst solution, and react it for 24 hours;

[0127] S3, adding 8 parts of rigid material to the melted main material, the rigid material is calcium carbonate;

[0128] S4, add 0.7 parts of plasticizer, the plasticizer is mainly di-n-butyl adipate, mix evenly at a temperature above 280°C, then add non-ionic surfactant and mix evenly, stop heating, the non-ionic surfactant is fatty alcohol polyoxyethylene ether;

[0129] S5, processed into regular spheres by injection molding;

[0130] S6, polishing the surface of the sphere;

[0131] S7. According to the thickness requirement, choose to use 16 strands to make a thin rope, tie a knot on one strand of the thin rope, and then tie a knot on the untied side again, so that the whole knot is stuck in the center of the sphere;

[0132] S8. Finally, unfold the end of the rope to form a tassel shape.

[0133] Experimental example:

[0134] Experimental data on the comparison of the plugging efficiency of the simulated plugging device for conventional temporary plugging balls and new guiding temporary plugging balls of the same size

[0135] Experiment with a hole-ball ratio of 1:1. Select a 10 mm hole diameter and a 15 mm ball.

[0136]

[0137] Experiment with a hole-ball ratio of 1:1.5. Select a 10 mm hole diameter and a 15 mm ball.

[0138]

[0139] Experiment with a hole-ball ratio of 1:2. Select a 10 mm hole diameter and a 15 mm ball.

[0140]

[0141]

[0142] Beneficial effects: By unfolding at the end of the rope to form a tassel shape, a design of a guiding tassel for the temporary plugging ball is formed, enabling its ability to sense the fluid direction at the crack, increasing the diversion ability. When plugging, the diversion effect of the tassel synergistically anchors the temporary plugging ball to the crack opening, and then the rope knot is tightened to plug the central hole of the temporary plugging ball, forming a reliable plug. After being placed, it flows with the fracturing fluid in the wellbore. Compared with traditional temporary plugging balls, the plugging efficiency is greatly improved; there are many choices for the main material type of the temporary plugging ball, which can be applied to different types of fracturing and acidizing. The finally prepared temporary plugging ball has performance advantages such as being soluble, having high strength, and adjustable density; it can be applied to selective fracturing of fractured wells, which is simple and convenient with obvious effects, and can effectively solve the problem of excessive pressure loss during repeated fracturing of old wells.

[0143] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to the embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel staged fracturing temporary plugging ball for fracturing acidification, comprising a spherical ball, characterized in that: A through hole is formed through the center of the spherical ball. A rope is arranged at the left end of the spherical ball. The right end face of the rope penetrates through the surface of the spherical ball and the inner wall of the through hole and extends to the right side of the spherical ball. Both ends of the rope are knotted, and the temporary plugging ball is clamped at the center of the two knots. The rope of the temporary plugging ball is made of soluble or degradable fiber. The spherical ball of the temporary plugging ball comprises the following raw materials in parts by weight: 80 parts - 90 parts of main material, which is one or a combination of PVA0388, PVA0588, PVA0988, PGA, and PLA; 5 parts - 10 parts of rigid material; 0.5 parts - 1 part of plasticizer. The manufacturing method of the temporary plugging ball comprises the following steps: S1. Use one or a combination of PVA0388, PVA0588, PVA0988, PGA, and PLA as the main material, and the dosage of the main material is 80 parts - 90 parts. S2. Crush the main material, place it at a temperature of 200 °C - 250 °C for mixing, heat and melt it, introduce high-purity nitrogen, stir evenly, then heat to 230 °C - 260 °C, add a catalyst solution, and react for 2 - 24 h. S3. Add 5 parts - 10 parts of rigid material to the melted main material. S4. Then add 0.5 parts - 1 part of plasticizer, mix evenly under the temperature condition above 280 °C, add a non-ionic surfactant and mix evenly, and stop heating. S5. Process into a regular spherical ball by an injection molding process. S6. Then polish the surface of the spherical ball. S7. According to the thickness requirement, select 4 / 8 / 16 / 24 strands to be stranded into a thin rope, then tie a knot with one or more stranded thin ropes, and then tie a knot again on the unknotted side to make the whole knot clamped at the center of the sphere. S8. Finally, unfold the end of the rope to form a tassel shape.

2. The novel staged fracturing temporary plugging ball for fracturing acidification according to claim 1, wherein: The material of the rope is selected from any one or more of PVA, PLA, and PGA.

3. A novel staged fracturing temporary plugging ball for fracturing acidizing according to claim 1, characterized in that: In step 1, one or a combination is used as the main material according to the actual required dissolution time and pressure-bearing capacity.

4. The novel staged fracturing temporary plugging ball for fracturing acidification according to claim 3, characterized in that: The rigid material in step 3 is calcium carbonate.

5. A novel staged fracturing temporary plugging ball for fracturing acidification, characterized in that: The plasticizer in step 4 adopts dibutyl sebacate or dibutyl adipate or dibutyl phthalate.

6. A novel sectional fracturing temporary plugging ball for fracturing acidification, characterized in that: The non-ionic surfactant in step 4 includes one or a combination of polyoxyethylene fatty amide, polyoxyethyl alkyl ether, polyoxyethylene alkyl amide, and fatty alcohol polyoxyethylene ether.

Images