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CN-121975510-A - Long-acting stable multi-solid waste composite propping agent and preparation method thereof

CN121975510ACN 121975510 ACN121975510 ACN 121975510ACN-121975510-A

Abstract

The invention belongs to the technical field of fracturing propping agent materials, and discloses a long-acting stable multi-solid waste composite propping agent and a preparation method thereof. The proppant takes steel slag, fly ash and granulated blast furnace slag as main raw materials, and is sintered at 1120-1260 ℃ to form a mullite-pyroxene composite ore phase framework by controlling the adding molar ratio of the raw materials, so that the long-term stability of high density and high-temperature high-pressure structure without collapse is realized. The invention further adopts fluorosilane and polyphosphonic acid to carry out surface cooperative grafting to construct a composite membrane layer with hydrophobic and anti-pollution functions, thereby obviously reducing the adsorption of stratum particles and the scaling of inorganic salt and maintaining the long-term smoothness of a crack diversion channel. The result shows that the propping agent has excellent mechanical strength and service stability, the retention rate of long-term diversion capacity in a high-temperature and high-mineralization fracturing fluid environment is more than 90%, the structural integrity is good, the compression resistance is more than 69 MPa, and the propping agent is suitable for long-term fracturing supporting requirements of complex reservoirs.

Inventors

  • CHEN TONGTAO
  • SONG CHENGYANG
  • ZHANG XING

Assignees

  • 贵阳鑫睿材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. The long-acting stable multi-solid waste composite propping agent is characterized by comprising, by weight, 30-50 parts of steel slag, 25-45 parts of fly ash, 10-20 parts of granulated blast furnace slag, 3-10 parts of kaolin and 1-5 parts of fluxing agent; The raw materials are sintered to form composite supporting particles, and the surface of the obtained propping agent is further grafted with a composite modified membrane layer constructed by cooperation of fluorosilane and polyphosphonic acid.
  2. 2. The proppant of claim 1, wherein the proppant particles are sintered to form a mineral structure comprising primarily two crystalline phases of mullite and pyroxene, wherein the mullite is present in an amount of 30% -60% and the pyroxene is present in an amount of 20% -40%.
  3. 3. A proppant according to claim 1 wherein said fluxing agent is selected from one or more of calcium fluoride, borax, sodium silicate.
  4. 4. The proppant of claim 1, wherein the composite modified membrane layer is formed on the surface of the particles by placing the proppant particles in a mixed solution containing fluorosilane and polyphosphonic acid, stirring and reacting for 1-2 hours at a temperature of 40-60 ℃ and a pH of 4-5, and washing and drying the reaction product.
  5. 5. A method for preparing a long-acting stable multi-solid waste composite propping agent, which is characterized by comprising the following steps of: s1, respectively crushing, screening and removing impurities from steel slag, fly ash, granulated blast furnace slag and kaolin, and drying fluxing agent; s2, adding the raw materials in the step S1 into mixing equipment, adding deionized water for wet mixing, feeding into a granulator for disc granulation, collecting wet particles and screening; s3, carrying out hot air drying on the classified wet particles, heating, preserving heat and cooling in a sintering furnace after drying, obtaining sintered particles, and screening to remove impurities; S4, adding mixed solution of fluorosilane and polyphosphonic acid into the sintered particles, stirring to perform grafting reaction, taking out the particles after the reaction is finished, and washing the surfaces by using ethanol or deionized water; S5, drying the washed particles by hot air, screening the particles after drying, and collecting the particles to obtain the composite propping agent.
  6. 6. The method for preparing propping agent according to claim 5, wherein in the step S1, the steel slag is crushed to a grain size smaller than or equal to 2 mm, the fly ash is sieved by 100 meshes, the granulated blast furnace slag is ball-milled to a grain size smaller than 80 meshes, the kaolin is dried for 2 hours at 80-100 ℃, and the fluxing agent is kept stand and dried at normal temperature for not less than 24 hours.
  7. 7. The method of producing propping agent according to claim 5, wherein the wet mixing time in step S2 is 15 to 30 minutes, the rotational speed of the disk granulator is 18 to 25 rpm, and the granulating time is 20 to 40 minutes.
  8. 8. The method for preparing the propping agent according to claim 5, wherein the sintering temperature in the step S3 is 1120-1260 ℃, the heating rate is 5-10 ℃ per minute, the heat preservation time is 60-120 minutes, and the cooling mode is furnace cooling.
  9. 9. The method for preparing a proppant according to claim 5, wherein the mass ratio of the fluorosilane to the polyphosphonic acid is 1:2-1:3, wherein the fluorosilane is one or more selected from perfluorooctyl triethoxysilane, trifluoropropyl trimethoxysilane, perfluorohexyl trimethoxysilane and perfluorodecyl triethoxysilane, and the polyphosphonic acid is one or more selected from 2-phosphinobutane-1, 2, 4-tricarboxylic acid, hydroxyphosphinoacetic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid and aminotrimethylene phosphonic acid.
  10. 10. The proppant of claim 1, wherein the proppant has a retention of conductivity of not less than 90% after being immersed in a hypersalinity simulated fracturing fluid for 30 days, and a surface hydrophobic-anti-scaling film is intact and free of spalling.

Description

Long-acting stable multi-solid waste composite propping agent and preparation method thereof Technical Field The invention belongs to the technical field of fracturing propping agent materials, and particularly relates to a long-acting stable multi-solid waste composite propping agent and a preparation method thereof. Background The fracturing propping agent is an indispensable key material in the hydraulic fracturing technology of the oil and gas reservoir, and has the functions of filling stratum cracks and forming high-permeability channels in the fracturing process so as to maintain the crack conductivity and further realize the efficient development of oil and gas resources. The existing fracturing propping agent mainly comprises a ceramsite propping agent, a quartz sand propping agent and a resin coated propping agent. The ceramsite propping agent has good compressive strength and thermal stability, and is widely applied to high-temperature deep oil and gas reservoirs. However, the traditional ceramic propping agent usually takes bauxite and corundum high-grade minerals as raw materials, has high preparation cost and strong resource dependence, and is not beneficial to large-scale popularization and application. In recent years, the utilization of industrial solid waste resources has been receiving a great deal of attention. The steel slag, the fly ash and the granulated blast furnace slag have good mineral composition and potential activity, and are suitable to be used as the basic raw materials of sintered ceramsite. However, the components among different solid wastes are complex, the direct mixing often causes unstable mineral phase structure in the sintering process, and the problems of cracks, expansion and insufficient strength are easy to occur, so that the application of the solid waste in the field of high-strength propping agents is limited. In addition, the existing propping agent has much neglect of anti-scaling and anti-pollution capabilities in the long-term service process, especially under the conditions of high mineralization degree and complex stratum, particles or scales are easy to be adsorbed on the surface of the propping agent, so that a diversion channel is blocked, and the development efficiency is obviously reduced. Disclosure of Invention In order to solve the defects in the background art, the invention aims to provide a long-acting stable multi-solid waste composite propping agent and a preparation method thereof, which are used for constructing a high-density mineral framework by adopting the cooperation of various industrial solid wastes of steel slag, fly ash and granulated blast furnace slag, and forming a hydrophobic-anti-scaling film layer by combining fluorosilane and polyphosphonic acid for synergistic grafting modification, thereby remarkably improving the compressive strength, the temperature resistance and the diversion stability of the propping agent and being suitable for fracturing operation of high-temperature high-mineralization oil and gas reservoirs. The aim of the invention can be achieved by the following technical scheme: The long-acting stable multi-solid waste composite propping agent comprises, by weight, 30-50 parts of steel slag, 25-45 parts of fly ash, 10-20 parts of granulated blast furnace slag, 3-10 parts of kaolin and 1-5 parts of fluxing agent; The raw materials are sintered to form composite supporting particles, and the surface of the obtained propping agent is further grafted with a composite modified membrane layer constructed by cooperation of fluorosilane and polyphosphonic acid. Further preferably, the mineral structure formed by sintering the proppant particles mainly comprises two crystal phases of mullite and pyroxene, wherein the content of mullite is 30% -60% and the content of pyroxene is 20% -40%. Further preferably, the fluxing agent is selected from one or more of calcium fluoride, borax, sodium silicate. Further preferably, the composite modified membrane layer is formed by placing the proppant particles in a mixed solution containing fluorosilane and polyphosphonic acid, stirring and reacting for 1-2 hours at the pH of 4-5 and the temperature of 40-60 ℃, and washing and drying the reaction product to form the hydrophobic-anti-scaling composite membrane layer on the surfaces of the particles. The preparation method of the long-acting stable multi-solid waste composite propping agent comprises the following steps: s1, respectively crushing, screening and removing impurities from steel slag, fly ash, granulated blast furnace slag and kaolin, and drying fluxing agent; s2, adding the raw materials in the step S1 into mixing equipment, adding deionized water for wet mixing, feeding into a granulator for disc granulation, collecting wet particles and screening; s3, carrying out hot air drying on the classified wet particles, heating, preserving heat and cooling in a sintering furnace after drying, obtaining sintered particles, an