Water-soluble resin cement paste for well cementation and preparation method thereof

Abstract

The invention provides water-soluble resin cement paste for well cementation and a preparation method thereof, and the water-soluble resin cement paste is prepared from the following raw materials in parts by mass: 100 parts of oil well cement, 35-45 parts of quartz sand, 8-12 parts of hydrophilic epoxy resin emulsion, 0.8-1.2 parts of accelerant, 5-6 parts of high-temperature fluid loss agent, 1-1.5 parts of expanding agent, 3-5 parts of high-temperature retarder, 0.8-1.2 parts of flow pattern regulator, 0.5 part of defoaming agent and 35-45 parts of water. The cement paste system has the density of 1.89 + / -0.02 g / cm < 3 >, has the excellent mechanical properties of good paste sedimentation stability, low filter loss, adjustable thickening time, high strength, low elastic modulus and low permeability after being cured, effectively improves the toughness and interface cementation capacity of a cement sheath, improves the gas channeling prevention effect, and can meet the well cementation construction requirements of deep oil and gas wells.

Description

Technical Field

[0001] The present invention belongs to the field of well cement slurries, and particularly relates to a water-soluble resin cement slurry for well cementing and a preparation method thereof. Background Art

[0002] With the continuous deepening of domestic oil and gas exploration and development, the drilling depth is getting deeper, the bottom hole temperature and pressure are getting higher, the number of deep wells is increasing, the downhole conditions are getting more complex, and at the same time, with the extension of the production time of natural gas wells, the annulus pressure in domestic natural gas wells is becoming increasingly serious. The main mechanisms of annulus pressure, i.e., wellbore failure, are casing buckling instability in the production interval and casing collapse in the reservoir, and the cement sheath is an important means to protect the casing. The sealing integrity of the cement sheath directly affects the formation sealing effect and the ability of the casing to resist collapse and deformation, thus affecting the risk probability of accidents.

[0003] In related technologies, usually elastic materials, latex or fibers are incorporated into the cement slurry to improve the toughness and deformation resistance of the cement stone. Most of the research on resins for well cementing focuses on oil-soluble resins and water-soluble phenolic resin cement slurries. Oil-soluble resins have significant effects on plugging and treating the problem of annulus pressure at the wellhead, but they cannot be well miscible with the cement slurry, it is difficult to form a stable emulsion system, and the on-site construction pipelines must be cleaned with organic solutions, which has the disadvantages of long working hours and high costs; water-soluble phenolic resins have high temperature sensitivity and are out of sync with the curing time of the cement slurry, resulting in great difficulty in overall adjustment of the cement slurry system and being not conducive to popularization and application. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a water-soluble resin cement slurry for well cementing and a preparation method thereof, and this cement slurry has a lower permeability.

[0005] The present invention provides a water-soluble resin cement slurry for well cementing, which includes the following raw materials in parts by mass:

[0006] 100 parts of oil well cement, 35 - 45 parts of quartz sand, 8 - 12 parts of hydrophilic epoxy resin emulsion, 0.8 - 1.2 parts of accelerator, 5 - 6 parts of high-temperature fluid loss reducer, 1 - 1.5 parts of expandant, 3 - 5 parts of high-temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer, 35 - 45 parts of water;

[0007] The mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9 - 1.1.

[0008] Preferably, the hydrophilic epoxy resin emulsion is prepared by the following method: epoxy resin EP-20, N-methylpyrrolidone and polyvinyl alcohol are mixed evenly, heated to 65-75 °C, phosphorus pentoxide is added, then heated to 80-90 °C, reacted for 170-190 min, then fumed silica and siloxane coupling agent are added, and the reaction is continued for 25-35 min. After cooling, the pH value is adjusted to neutral to obtain the hydrophilic epoxy resin emulsion.

[0009] Specifically, epoxy resin EP-20, N-methylpyrrolidone and polyvinyl alcohol are mixed evenly; slowly heated to 70 °C, and phosphorus pentoxide is added in batches according to the molar ratio of EP-20 / P 2 O 5 =(1.3:1.0)-(1.3:1.2), heated to 85 °C, and reacted at a constant temperature for 3 h; fumed silica and siloxane coupling agent are added, and the reaction is continued for 0.5 h while stirring. After washing with distilled water and cooling to room temperature, the pH value of the solution is adjusted to about 7 with potassium hydroxide solution to obtain the hydrophilic epoxy resin emulsion with a solid content of 55%-60%.

[0010] Preferably, the SiO content in the quartz sand is ≥97%, and the particle size is 120-200 mesh. 2 content ≥97%, particle size 120-200 mesh.

[0011] Preferably, the flow pattern regulator is selected from polycarboxylic acids.

[0012] Preferably, the mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:1.

[0013] Preferably, the high-temperature fluid loss reducer is an AMPS polymer-based fluid loss reducer;

[0014] The high-temperature retarder is a hydroxycarboxylic acid-based retarder and / or an AMPS polymer-based retarder;

[0015] The oil well cement is oil well G-class cement conforming to API specifications;

[0016] Preferably, the accelerator is a mixture of oil-based amines and imidazoles.

[0017] Preferably, the expander is a mixture of ettringite, calcium oxide and magnesium oxide.

[0018] Preferably, the defoamer is an organosilicon-based emulsion defoamer.

[0019] Preferably, the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of 150-mesh quartz sand, 0.8 part of accelerator, 1.5 parts of expander, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 0.5 part of defoamer, and 42 parts of water;

[0020] Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 15 parts of quartz sand with a mesh size of 200, 1 part of accelerator, 1.5 parts of expansive agent, 10 parts of hydrophilic epoxy resin emulsion, 5.5 parts of high-temperature fluid loss reducer, 3.8 parts of high-temperature retarder, 1 part of flow pattern regulator, 0.5 part of defoamer, and 41 parts of water;

[0021] Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 20 parts of quartz sand with a mesh size of 200, 1 part of accelerator, 1 part of expansive agent, 12 parts of hydrophilic epoxy resin emulsion, 6 parts of high-temperature fluid loss reducer, 5 parts of high-temperature retarder, 1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 39 parts of water;

[0022] Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 1.2 parts of accelerator, 1.5 parts of expansive agent, 12 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 0.5 part of defoamer, and 38 parts of water;

[0023] Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 0.8 part of accelerator, 1.5 parts of expansive agent, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3.5 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 0.5 part of defoamer, and 42 parts of water.

[0024] The present invention provides a method for preparing a water-soluble resin cement slurry for well cementing according to the above technical solution, including the following steps:

[0025] Step 1) Mix 100 parts of oil well cement, 35 - 45 parts of quartz sand, 0.8 - 1.2 parts of accelerator, and 1 - 1.5 parts of expansive agent evenly to obtain a first mixture;

[0026] Step 2) Mix 8 - 12 parts of hydrophilic epoxy resin emulsion, 5 - 6 parts of high-temperature fluid loss reducer, 3 - 5 parts of high-temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 35 - 45 parts of water, and stir at a stirring speed of 4000 r / min for 3 - 5 min to obtain a second mixture;

[0027] Step 3) Maintain a stirring speed of 4000 r / min and pour the first mixture into the second mixture within 20 s;

[0028] Step 4) Stir at a stirring speed of 12000 r / min for 35 s to obtain a water-soluble resin cement slurry for well cementing.

[0029] The present invention provides a water-soluble resin cement slurry for well cementing, which comprises the following raw materials in parts by mass: 100 parts of oil well cement, 35-45 parts of quartz sand, 8-12 parts of hydrophilic epoxy resin emulsion, 0.8-1.2 parts of accelerator, 5-6 parts of high-temperature fluid loss reducer, 1-1.5 parts of expansive agent, 3-5 parts of high-temperature retarder, 0.8-1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 35-45 parts of water; the mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9-1.1. The density of the cement slurry system of the present invention is 1.89±0.02 g / cm 3 , and has good sedimentation stability of the slurry body, low filtration loss, adjustable thickening time, and excellent mechanical properties of high strength, low elastic modulus, and low permeability after curing, effectively improving the toughness and interfacial bonding ability of the cement sheath, enhancing the gas channeling prevention effect, and meeting the requirements of well cementing construction for deep oil and gas wells. Detailed embodiments

[0030] The present invention provides a water-soluble resin cement slurry for well cementing, which comprises the following raw materials in parts by mass:

[0031] 100 parts of oil well cement, 35-45 parts of quartz sand, 8-12 parts of hydrophilic epoxy resin emulsion, 0.8-1.2 parts of accelerator, 5-6 parts of high-temperature fluid loss reducer, 1-1.5 parts of expansive agent, 3-5 parts of high-temperature retarder, 0.8-1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 35-45 parts of water;

[0032] The mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9-1.1.

[0033] The water-soluble resin cement slurry system provided by the present invention has excellent comprehensive properties. The liquid water-soluble epoxy resin wraps the cement particles. During the curing process of the epoxy resin, a structural deformation center with a certain strength is formed around the voids, which can restrain the generation and development of microcracks and absorb strain energy. The network structure formed by the resin absorbs strain energy, weakens the impact force borne by the resin cement, reduces microcracks and stress concentration, controls the generation and development of microcracks, improves the strength and toughness of the cement stone, and enables the resin cement to have both a lower elastic modulus and a higher compressive strength. At the same time, the cement stone structure is more dense, effectively reducing the gas permeability and preventing gas channeling, and effectively ensuring the sealing integrity of the cement sheath. The water-soluble resin cement slurry system of the present invention is applicable to well cementing construction operations for deep oil and gas wells.

[0034] The preparation raw materials of the water-soluble resin cement slurry for well cementing provided by the present invention include 100 parts of oil well cement, and the oil well cement is oil well G-class cement conforming to API specifications. In a specific embodiment, the oil well cement is Aksu G-class cement.

[0035] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 35-45 parts of quartz sand, wherein the SiO 2 content in the quartz sand is ≥97%, and the particle size is 120-200 mesh. In specific embodiments, the quartz sand is selected from one or more of 120-mesh quartz sand, 150-mesh quartz sand, and 200-mesh quartz sand. In the present invention, different particle sizes of quartz sand are used in combination to coordinate the stability and flow state of the slurry.

[0036] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 8-12 parts of hydrophilic epoxy resin emulsion. The mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9-1.1, preferably 10:0.95-1.05, more preferably 10:0.98-1.02; in specific embodiments, the mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:1. In this application, the types, amounts, and process conditions of the raw materials will all affect the thickening time of the cement slurry. Under the control of other experimental conditions in the present invention, it is found that when the mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9-1.1, the influence on the thickening time of the cement slurry is the smallest.

[0037] The hydrophilic epoxy resin emulsion in the present invention is prepared by the following method:

[0038] Epoxy resin EP-20, N-methylpyrrolidone, and polyvinyl alcohol are mixed evenly, heated to 65-75°C, phosphorus pentoxide is added, then heated to 80-90°C, reacted for 170-190 min, then fumed silica and siloxane coupling agent are added, and the reaction continues for 25-35 min. After cooling, the pH value is adjusted to neutral to obtain the hydrophilic epoxy resin emulsion.

[0039] Specifically, epoxy resin EP-20, N-methylpyrrolidone, and polyvinyl alcohol are mixed evenly; slowly heated to 70°C, and phosphorus pentoxide is added in batches according to the molar ratio EP-20 / P 2 O 5 =(1.3:1.0)-(1.3:1.2), heated to 85°C, and reacted at a constant temperature for 3 h; fumed silica and siloxane coupling agent are added, and the reaction continues for 0.5 h while stirring. After washing with distilled water and cooling to room temperature, the pH value of the solution is adjusted to about 7 with potassium hydroxide solution to obtain the hydrophilic epoxy resin emulsion.

[0040] More specifically, the hydrophilic epoxy resin emulsion is prepared by the following method:

[0041] 100 parts by mass of epoxy resin EP-20, 3-5 parts by mass of N-methylpyrrolidone, and 0.3-0.5 parts by mass of polyvinyl alcohol are added to a three-necked flask; heated to 35°C, and stirred to make the reaction system mixed evenly; slowly heated to 70°C, and according to the molar ratio EP-20 / P2 O 5 P₂O₅ was added in batches at (1.3:1.0) to (1.3:1.2). After the addition was complete, the temperature was raised to 85 °C and the reaction was carried out at a constant temperature for 3 h. 2 to 4 parts by mass of fumed silica and 0.3 to 0.4 parts by mass of siloxane coupling agent were added, and the reaction was continued for 0.5 h with stirring. After washing with distilled water and cooling to room temperature, the pH of the solution was adjusted to approximately 7 with potassium hydroxide solution to obtain a hydrophilic epoxy resin emulsion. The solid content of the hydrophilic epoxy resin emulsion was 55% to 60%.

[0042] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 0.8 to 1.2 parts of a promoter; the promoter is a mixture of oil-based amines and imidazoles. In a specific embodiment, the model of the promoter is GH-2. The mass ratio of the hydrophilic epoxy resin emulsion to the promoter is 10:1. Under this ratio, the influence on the thickening time of the cement slurry is the smallest.

[0043] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 5 to 6 parts of a high-temperature fluid loss reducer; the high-temperature fluid loss reducer is an AMPS polymer-based fluid loss reducer. In a specific embodiment, the model of the high-temperature fluid loss reducer is BS100L-G.

[0044] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 1 to 1.5 parts of an expander; the expander is a mixture of ettringite, calcium oxide and magnesium oxide. In a specific embodiment, the model of the expander is BS500.

[0045] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 0.5 part of an antifoaming agent; the antifoaming agent is an organosilicon-based emulsion antifoaming agent. In a specific embodiment, the antifoaming agent is BP-1C.

[0046] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 3 to 5 parts of a high-temperature retarder; the high-temperature retarder is a hydroxycarboxylic acid-based retarder and / or an AMPS polymer-based retarder, preferably selected from one or more of M63L, BS200G and BS200R.

[0047] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 0.8 to 1.2 parts of a flow pattern regulator, and the flow pattern regulator is a polycarboxylic acid type. In a specific embodiment, the model of the flow pattern regulator is GD-2.

[0048] The raw materials for preparing the water-soluble resin cement slurry for well cementing provided by the present invention include 35 to 45 parts of water.

[0049] In the embodiments of the present invention, the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 0.8 part of GH-2 accelerator, 1.5 parts of BS500 expander, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of BS100L-G high-temperature fluid loss reducer, 3 parts of BS200G high-temperature retarder, 0.8 part of GD-2 flow pattern regulator, 0.5 part of BP-1C defoamer, and 42 parts of water;

[0050] Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 15 parts of quartz sand with a mesh size of 200, 1 part of GH-2 accelerator, 1.5 parts of BS500 expander, 10 parts of hydrophilic epoxy resin emulsion, 5.5 parts of BS100L-G high-temperature fluid loss reducer, 2.8 parts of M63L high-temperature retarder, 1 part of BS200R high-temperature retarder, 1 part of GD-2 flow pattern regulator, 0.5 part of BP-1C defoamer, and 41 parts of water;

[0051] Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 20 parts of quartz sand with a mesh size of 200, 1 part of GH-2 accelerator, 1 part of BS500 expander, 12 parts of hydrophilic epoxy resin emulsion, 6 parts of BS100L-G high-temperature fluid loss reducer, 3.5 parts of M63L high-temperature retarder, 1.5 parts of BS200R high-temperature retarder, 1.2 part of GD-2 flow pattern regulator, 0.5 part of BP-1C defoamer, and 39 parts of water;

[0052] Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 1.2 parts of GH-2 accelerator, 1.5 parts of BS500 expander, 12 parts of hydrophilic epoxy resin emulsion, 5 parts of BS100L-G high-temperature fluid loss reducer, 3 parts of BS200G high-temperature retarder, 0.8 part of GD-2 flow pattern regulator, 0.5 part of BP-1C defoamer, and 38 parts of water;

[0053] Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 0.8 part of GH-2 accelerator, 1.5 parts of BS500 expander, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of BS100L-G high-temperature fluid loss reducer, 3.5 parts of BS200G high-temperature retarder, 0.8 part of GD-2 flow pattern regulator, 0.5 part of BP-1C defoamer, and 42 parts of water.

[0054] The present invention also provides a preparation method for the water-soluble resin cement slurry for well cementing according to the above technical solution, including the following steps:

[0055] Mix 100 parts of oil well cement, 35 - 45 parts of quartz sand, 8 - 12 parts of hydrophilic epoxy resin emulsion, 0.8 - 1.2 parts of accelerator, 5 - 6 parts of high - temperature fluid loss reducer, 1 - 1.5 parts of expandant, 3 - 5 parts of high - temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer and 35 - 45 parts of water evenly to obtain the water - soluble resin cement slurry for well cementing.

[0056] Specifically, the preparation method of the water - soluble resin cement slurry for well cementing specifically includes the following steps:

[0057] Step 1): Mix 100 parts of oil well cement, 35 - 45 parts of quartz sand, 0.8 - 1.2 parts of accelerator and 1 - 1.5 parts of expandant evenly to obtain the first mixture.

[0058] Step 2): Mix 8 - 12 parts of resin, 5 - 6 parts of high - temperature fluid loss reducer, 3 - 5 parts of high - temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer and 35 - 45 parts of water and stir. Stir at a stirring speed of 4000 r / min for 3 - 5 min to obtain the second mixture.

[0059] Step 3): Keep the stirring speed at 4000 r / min and pour the first mixture into the second mixture within 20 s.

[0060] Step 4): Stir at a stirring speed of 12000 r / min for 35 s to obtain the water - soluble resin cement slurry for well cementing.

[0061] The above - mentioned method is simple and easy to realize industrialization. The water - soluble resin cement slurry system for well cementing prepared by this method can be mutually soluble with the cement slurry to form a stable system, reduce the elastic modulus of the cement stone while having little influence on the compressive strength of the cement stone, and has a low permeability, which can effectively maintain the sealing integrity of the cement sheath. Moreover, by modifying the oil - soluble epoxy resin to prepare water - soluble epoxy resin, the preparation process is simple and easy to operate.

[0062] To further illustrate the present invention, the following is a detailed description of a water - soluble resin cement slurry for well cementing and its preparation method provided by the present invention in combination with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0063] Preliminary Embodiment

[0064] Add 100 parts by mass of epoxy resin EP-20, 4 parts by mass of N-methylpyrrolidone, and 0.4 parts by mass of polyvinyl alcohol into a three-necked flask; heat up to 35 °C and stir to make the reaction system mix evenly; slowly heat up to 70 °C, add 22 parts by mass of phosphorus pentoxide in batches. After adding, heat up to 85 °C and keep the temperature constant for reaction for 3 h; add 3 parts by mass of fumed silica and 0.35 parts by mass of siloxane coupling agent, and continue to react for 0.5 h under stirring. After washing with distilled water and cooling to room temperature, adjust the pH of the solution to ≈7 with potassium hydroxide solution to obtain a hydrophilic epoxy resin emulsion with a solid content of 57%.

[0065] Example 1

[0066] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 0.8 part of GH-2, 1.5 parts of BS500, 8 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS 100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, and 42 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0067] The thickening experimental conditions of the cement slurry are 130 °C * 95 MPa * 90 min, the rheological property experimental conditions are normal temperature and pressure, the water loss experimental conditions are 130 °C * 6.9 MPa * 30 min, and the curing conditions of the test blocks for compressive strength test are 160 °C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T19139; the curing conditions of the test blocks for triaxial mechanical test are 130 °C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T6466; the curing conditions of the test blocks for permeability test are 130 °C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T19139 is followed. The experimental results are shown in Table 1 and Table 2.

[0068] Example 2

[0069] Weigh 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand (120 mesh), 15 parts of quartz sand (200 mesh), 1 part of GH-2, 1.5 parts of BS500, 10 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5.5 parts of BS100L-G, 2.8 parts of M63L, 1 part of BS200R, 1 part of GD-2, 0.5 part of BP-1C, and 41 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0070] The thickening test conditions for the cement slurry are 140°C * 110 MPa * 90 min, the rheological property test conditions are normal temperature and pressure, the water loss test conditions are 140°C * 6.9 MPa * 30 min, and the curing conditions for the test blocks of compressive strength test are 170°C * 21 MPa * 48 h, which are carried out in accordance with the test method for oil well cement in GB / T 19139; the curing conditions for the test blocks of triaxial mechanical test are 140°C * 21 MPa * 48 h, which are carried out in accordance with the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions for the test blocks of permeability test are 140°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The experimental results are shown in Table 1 and Table 2.

[0071] Example 3

[0072] Weigh 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand (120 mesh), 20 parts of quartz sand (200 mesh), 21.2 parts of GH, 1 part of BS500, 12 parts of the hydrophilic epoxy resin emulsion in the preliminary example, 6 parts of BS100L-G, 3.5 parts of M63L, 1.5 parts of BS200R, 1.2 parts of GD-2, 0.5 part of BP-1C, and 39 parts of water. Mix the above materials and stir evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0073] The thickening test conditions for the cement slurry are 150°C * 140 MPa * 90 min, the rheological property test conditions are normal temperature and pressure, the water loss test conditions are 150°C * 6.9 MPa * 30 min, and the curing conditions for the test blocks of compressive strength test are 180°C * 21 MPa * 48 h, which are carried out in accordance with the test method for oil well cement in GB / T 19139; the curing conditions for the test blocks of triaxial mechanical test are 180°C * 21 MPa * 48 h, which are carried out in accordance with the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions for the test blocks of permeability test are 180°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The results are shown in Table 1 and Table 2.

[0074] Example 4

[0075] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.2 parts of GH-2, 1.5 parts of BS500, 12 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 parts of GD-2, 0.5 parts of BP-1C, and 38 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry. The thickening experiment conditions of the cement slurry are 130°C * 95 MPa * 90 min, the rheological property experiment conditions are normal temperature and pressure, the water loss experiment conditions are 130°C * 6.9 MPa * 30 min, and the curing conditions of the test blocks for compressive strength test are 160°C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T 19139; the curing conditions of the test blocks for triaxial mechanical test are 130°C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions of the test blocks for permeability test are 130°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is carried out. The experimental results are shown in Table 1 and Table 2.

[0076] Example 5

[0077] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 0.8 parts of GH-2, 1.5 parts of BS500, 8 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3.5 parts of BS200G, 0.8 parts of GD-2, 0.5 parts of BP-1C, and 42 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry. The thickening experiment conditions of the cement slurry are 130°C * 95 MPa * 90 min, and the experimental results are shown in Table 1.

[0078] Comparative Example 1

[0079] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.5 parts of BS500, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 parts of GD-2, and 48 parts of water. Mix and stir the above materials evenly according to GB / T 19139 to obtain the cement slurry.

[0080] The thickening experiment conditions of the cement slurry are 130°C * 95 MPa * 90 min, the rheological property experiment conditions are normal temperature and pressure, the water loss experiment conditions are 130°C * 6.9 MPa * 30 min, and the curing conditions of the test blocks for compressive strength test are 160°C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T 19139; the curing conditions of the test blocks for triaxial mechanical test are 130°C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions of the test blocks for permeability test are 130°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The experimental results are shown in Table 1 and Table 2.

[0081] Comparative Example 2

[0082] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 0.5 part of GH-2, 1.5 parts of BS500, 5 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, and 45 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0083] The curing conditions of the test blocks for compressive strength test are 160°C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T 19139; the curing conditions of the test blocks for triaxial mechanical test are 130°C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions of the test blocks for permeability test are 130°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The experimental results are shown in Table 2.

[0084] Comparative Example 3

[0085] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.5 parts of GH-2, 1.5 parts of BS500, 15 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, and 35 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0086] The curing conditions for the compressive strength test specimens are 160°C * 21 MPa * 48 h, and the test is carried out in accordance with the test method for oil well cement in GB / T 19139; the curing conditions for the triaxial mechanical test specimens are 130°C * 21 MPa * 48 h, and the test is carried out in accordance with the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions for the permeability test specimens are 130°C * 21 MPa * 48 h, and the test is carried out for the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139. The experimental results are shown in Table 2.

[0087] Comparative Example 4

[0088] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 0.4 part of GH-2, 1.5 parts of BS500, 8 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, and 42 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry. The thickening experimental conditions of the cement slurry are 130°C * 95 MPa * 90 min, and the experimental results are shown in Table 1.

[0089] Comparative Example 5

[0090] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.2 parts of GH-2, 1.5 parts of BS500, 8 parts of the hydrophilic epoxy resin emulsion in the preparatory example, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, and 42 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry. The thickening experimental conditions of the cement slurry are 130°C * 95 MPa * 90 min, and the experimental results are shown in Table 1.

[0091] Comparative Example 6

[0092] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.5 parts of BS500, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 part of GD-2, 0.5 part of BP-1C, 8 parts of water-soluble phenolic resin, and 50 parts of water. Mix and stir the above materials evenly according to the preparation method of the water-soluble resin cement slurry for well cementing to obtain the water-soluble resin cement slurry.

[0093] The thickening test conditions of the cement slurry are 130°C * 95 MPa * 90 min, the rheological property test conditions are normal temperature and pressure, the water loss test conditions are 130°C * 6.9 MPa * 30 min, and the curing conditions of the test blocks for compressive strength test are 160°C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T 19139; the curing conditions of the test blocks for triaxial mechanical test are 130°C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions of the test blocks for permeability test are 130°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The test results are shown in Table 1 and Table 2.

[0094] Comparative Example 7

[0095] Weigh 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand (150 mesh), 1.5 parts of BS500, 5 parts of BS100L-G, 3 parts of BS200G, 0.8 parts of GD-2, 0.5 parts of BP-1C, and 50 parts of water. Mix and stir the above materials evenly according to GB / T 19139 to prepare the cement slurry. Then mix 8 parts of oil-soluble epoxy aldehyde resin with the prepared cement slurry and stir at a speed of 12,000 r / min for 35 s to obtain the oil-soluble resin cement slurry.

[0096] The thickening test conditions of the cement slurry are 130°C * 95 MPa * 90 min, the rheological property test conditions are normal temperature and pressure, the water loss test conditions are 130°C * 6.9 MPa * 30 min, and the curing conditions of the test blocks for compressive strength test are 160°C * 21 MPa * 48 h, which are carried out according to the test method for oil well cement in GB / T 19139; the curing conditions of the test blocks for triaxial mechanical test are 130°C * 21 MPa * 48 h, which are carried out according to the test method for the properties of oil well cement stone in SY / T 6466; the curing conditions of the test blocks for permeability test are 130°C * 21 MPa * 48 h, and the gas permeability in 11.7 of the test method for oil well cement in GB / T 19139 is followed. The test results are shown in Table 1 and Table 2.

[0097] Table 1 Basic performance parameters of the cement slurry

[0098]

[0099] As can be seen from Table 1, the water loss of the well cement slurry provided by the present invention is lower than that of the cement slurries in Comparative Example 1, Comparative Example 6, and Comparative Example 7, there is no free liquid, and the rheological properties are good at normal temperature and pressure, which are better than those in Comparative Example 6 and Comparative Example 7, facilitating the pumping of the well cementing construction on site. The thickening time of the resin cement slurry provided by the present invention is adjustable and can meet the requirements of the well cementing construction on site.

[0100] By comparing the thickening times of Example 1, Comparative Example 4, and Comparative Example 5 with that of Comparative Example 1, it can be seen that the ratio of the accelerator to the resin has an impact on the thickening time. When the ratio of the resin to the accelerator is 10:1, the impact on the thickening time of the cement slurry is the smallest.

[0101] Table 2 Cementing Performance of Cement Slurry

[0102]

[0103] As can be seen from Table 2, compared with Comparative Example 1, the addition of water-soluble epoxy resin can effectively reduce the permeability and elastic modulus of the cement stone. Compared with Comparative Example 6, the impact of water-soluble epoxy resin on the strength of the cement stone is relatively small. Compared with Comparative Example 7, after the oil-soluble epoxy resin is modified into a water-soluble epoxy resin, it is more evenly distributed in the cement slurry, and the performance of the cement stone such as anti-permeability ability, compressive strength, and elasticity and toughness has been improved. When the resin dosage is 5%, the elastic modulus exceeds 6 GPa, which cannot meet the index requirement of the elastic modulus of the cement stone ≤ 6 GPa in the industry standard SY / T7648-2021. When the resin dosage is 15%, while the elastic modulus of the cement stone decreases significantly, the compressive strength of the cement stone is also damaged. Therefore, the recommended resin dosage of the present invention is 8-12%.

[0104] From the above examples, it can be seen that the cement stone formed by the resin cement slurry provided by the present invention has the characteristics of high strength, low elastic modulus, and low permeability. The compressive strength at 48 h exceeds 30 MPa, the elastic modulus < 6 GPa, the permeability < 0.02 mD, and the temperature resistance reaches 180 °C, which can meet the requirements of the cement slurry performance for cementing construction of deep oil and gas wells, gas storage wells, and gas injection and production wells, and ensure the safety of cementing construction and subsequent production operations.

[0105] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A water-soluble resin cement slurry for well cementing, calculated by mass parts, comprises the following raw materials: 100 parts of oil well cement, 35 - 45 parts of quartz sand, 8 - 12 parts of hydrophilic epoxy resin emulsion, 0.8 - 1.2 parts of accelerator, 5 - 6 parts of high-temperature fluid loss reducer, 1 - 1.5 parts of expandant, 3 - 5 parts of high-temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer, 35 - 45 parts of water; The mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:0.9 - 1.

1.

2. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the hydrophilic epoxy resin emulsion is prepared by the following method: Epoxy resin EP-20, N-methylpyrrolidone and polyvinyl alcohol are mixed evenly, heated to 65 - 75 °C, phosphorus pentoxide is added, then heated to 80 - 90 °C, reacted for 170 - 190 min, then fumed silica and siloxane coupling agent are added, and the reaction continues for 25 - 35 min. After cooling, the pH value is adjusted to neutral to obtain the hydrophilic epoxy resin emulsion.

3. The water-soluble resin cement slurry for well cementing according to claim 2, wherein, the hydrophilic epoxy resin emulsion is specifically prepared by the following method: 100 mass parts of epoxy resin EP-20, 3 - 5 mass parts of N-methylpyrrolidone, and 0.3 - 0.5 mass parts of polyvinyl alcohol are added into a three-necked flask; Heat to 35°C and stir to mix the reaction system evenly; slowly heat to 70°C, and add phosphorus pentoxide in batches according to the molar ratio of EP-20 / P 2 O 5 =(1.3:1.0) to (1.3:1.2). After adding, heat to 85°C and carry out a constant-temperature reaction for 3 h; add 2-4 parts by mass of fumed silica and 0.3-0.4 parts by mass of siloxane coupling agent, and continue the reaction for 0.5 h under stirring. After washing with distilled water and cooling to room temperature, adjust the pH of the solution to approximately 7 with potassium hydroxide solution to obtain a hydrophilic epoxy resin emulsion; The solid content of the hydrophilic epoxy resin emulsion is 55% - 60%.

4. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, The SiO in the quartz sand 2 content ≥ 97%, and the particle size is 120 - 200 mesh.

5. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the flow pattern regulator is selected from polycarboxylic acids.

6. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the mass ratio of the hydrophilic epoxy resin emulsion to the accelerator is 10:

1.

7. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the high-temperature fluid loss reducer is an AMPS polymer type fluid loss reducer; the high-temperature retarder is a hydroxycarboxylic acid type retarder and / or an AMPS polymer type retarder; the oil well cement is oil well G-class cement conforming to API specifications; the accelerator is a mixture of oil-based amines and imidazoles.

8. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the expandant is a mixture of ettringite, calcium oxide and magnesium oxide; the defoamer is an organosilicon type emulsion defoamer.

9. The water-soluble resin cement slurry for well cementing according to claim 1, wherein, the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of 150-mesh quartz sand, 0.8 part of accelerator, 1.5 parts of expandant, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 42 parts of water; Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 15 parts of quartz sand with a mesh size of 200, 1 part of accelerator, 1.5 parts of expansive agent, 10 parts of hydrophilic epoxy resin emulsion, 5.5 parts of high-temperature fluid loss reducer, 3.8 parts of high-temperature retarder, 1 part of flow pattern regulator, 0.5 part of defoamer, and 41 parts of water; Or the raw materials include 100 parts of Aksu G-class oil well cement, 25 parts of quartz sand with a mesh size of 120, 20 parts of quartz sand with a mesh size of 200, 1 part of accelerator, 1 part of expansive agent, 12 parts of hydrophilic epoxy resin emulsion, 6 parts of high-temperature fluid loss reducer, 5 parts of high-temperature retarder, 1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 39 parts of water; Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 1.2 parts of accelerator, 1.5 parts of expansive agent, 12 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 0.5 part of defoamer, and 38 parts of water; Or the raw materials include 100 parts of Aksu G-class oil well cement, 35 parts of quartz sand with a mesh size of 150, 0.8 part of accelerator, 1.5 parts of expansive agent, 8 parts of hydrophilic epoxy resin emulsion, 5 parts of high-temperature fluid loss reducer, 3.5 parts of high-temperature retarder, 0.8 part of flow pattern regulator, 0.5 part of defoamer, and 42 parts of water.

10. A method for preparing the water-soluble resin cement slurry for well cementing according to any one of claims 1 to 9, comprising the following steps: Step 1) Mix 100 parts of oil well cement, 35 - 45 parts of quartz sand, 0.8 - 1.2 parts of accelerator, and 1 - 1.5 parts of expansive agent evenly to obtain a first mixture; Step 2) Mix 8 - 12 parts of hydrophilic epoxy resin emulsion, 5 - 6 parts of high-temperature fluid loss reducer, 3 - 5 parts of high-temperature retarder, 0.8 - 1.2 parts of flow pattern regulator, 0.5 part of defoamer, and 35 - 45 parts of water, and stir at a stirring speed of 4000 r / min for 3 - 5 min to obtain a second mixture; Step 3) Keep the stirring speed at 4000 r / min and pour the first mixture into the second mixture within 20 s; Step 4) Stir at a stirring speed of 12000 r / min for 35 s to obtain the water-soluble resin cement slurry for well cementing.

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