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CN-121975511-A - Bionic dandelion propping agent system and preparation method and application thereof

CN121975511ACN 121975511 ACN121975511 ACN 121975511ACN-121975511-A

Abstract

The invention provides a bionic dandelion propping agent system and a preparation method and application thereof, the bionic dandelion propping agent system has the characteristics of simple process, low energy consumption, environmental protection and no pollution, and the bionic dandelion propping agent system is prepared by specifically compounding modified tailing particles and modified fibers, the chemical affinity of the surface active sites of the tailing particles and the calcium carbonate crystals and the bridging effect of the calcium carbonate crystals are utilized to enable the tailing particles and the fibers to self-assemble in the fracturing fluid to form a stable dandelion-like cluster structure. The structure remarkably improves the suspension transportation performance of the tailing propping agent in the fracturing fluid, can carry the tailing propping agent to the deep part of a crack and realize efficient filling, and meanwhile, the formed cluster sand dike constructs a hypertonic pore channel, and even if part of tailing particles are broken under high pressure, the cluster structure can still maintain the overall configuration and pore connectivity by means of the winding action of fibers, so that the difficulty of low strength of the tailing material is skillfully avoided, and a brand new path is provided for realizing the bulk and high-value utilization of the tailings.

Inventors

  • LI JUN

Assignees

  • 西南石油大学

Dates

Publication Date
20260505
Application Date
20260402

Claims (10)

  1. 1. A biomimetic dandelion proppant system, characterized in that the proppant system comprises modified tailing proppant particles and modified fibers; Wherein the mass ratio of the modified tailing propping agent particles to the modified fibers is 99.9-99 percent, namely 0.1-1 percent; The modified tailing propping agent particles are tailing particles treated by a modified treatment liquid, and the modified treatment liquid comprises urease, urea and a calcium source; The modified fiber is a fiber subjected to surface treatment, and the surface of the modified fiber is loaded with calcium carbonate crystals and a polydopamine layer.
  2. 2. The bionic dandelion proppant system according to claim 1, wherein the tailings particles are selected from one or more of iron tailings, copper tailings, lead tailings, zinc tailings, nickel tailings, vanadium titanium tailings, gold tailings, and the tailings particles have a particle size of 20/40 mesh, 30/50 mesh, 40/70 mesh, 70/140 mesh, 140/300 mesh or 300/600 mesh.
  3. 3. The bionic dandelion proppant system according to claim 1, wherein the volume ratio of urease, urea and calcium source in the modified treatment fluid is 1-2:1-2, the urea is provided in the form of aqueous solution with the concentration of 30-60g/L, the calcium source is provided in the form of aqueous solution with the concentration of 80-500g/L, and the calcium source is selected from one or more of calcium chloride, calcium nitrate, calcium acetate, calcium lactate and calcium lignan.
  4. 4. The biomimetic dandelion proppant system of claim 1, wherein the urease is produced from a feedstock comprising urease-rich plant seeds selected from the group consisting of one or more of red sword bean, white sword bean, pigeon pea, soybean, pea, peanut.
  5. 5. The bionic dandelion proppant system according to claim 1, wherein the preparation raw materials of the modified fiber comprise basic fiber, the basic fiber is selected from one or a compound of at least two of mineral fiber, polyester fiber, polyamide fiber, polyvinyl alcohol fiber, polyacrylonitrile fiber, polypropylene fiber, polyvinyl chloride fiber, viscose fiber, acetate fiber, cuprammonium fiber, cellulose fiber and basalt fiber, and the length of the basic fiber is 1-20mm.
  6. 6. The bionic dandelion proppant system according to claim 1, wherein the modified fiber is prepared by sequentially performing acid liquor activation treatment, calcium source solution soaking treatment and carbonate solution soaking treatment on a base fiber, and finally placing the base fiber in Tris-HCl buffer solution containing dopamine hydrochloride for reaction to obtain the modified fiber.
  7. 7. The bionic dandelion proppant system according to claim 6, wherein the acid solution is one or more of hydrochloric acid, acetic acid and sulfuric acid, the concentration is 3-10g/L, the calcium source solution is an aqueous solution of a calcium-containing reagent, the concentration is 80-500g/L, the calcium-containing reagent is one or more of calcium chloride, calcium nitrate, calcium acetate, calcium lactate and calcium lignan, the carbonate solution is an aqueous solution of carbonate-containing reagent, the concentration is 80-500g/L, the carbonate-containing reagent is one or more of sodium carbonate, sodium bicarbonate and ammonium carbonate, the pH value of the Tris-HCl buffer is 8-9, and the mass concentration of the dopamine hydrochloride in the Tris-HCl buffer is 0.1-5g/L.
  8. 8. A method of making the biomimetic dandelion proppant system of any one of claims 1-7, comprising a step of preparing modified tailing proppant particles and a step of preparing modified fibers; The preparation method of the modified tailing propping agent particles comprises the steps of adding the tailing particles into a modified treatment liquid, standing at 20-40 ℃ for reaction for 24-72 hours, filtering out and drying to obtain the modified tailing propping agent particles, wherein the modified treatment liquid comprises urease, urea and a calcium source; The preparation method of the modified fiber comprises the steps of soaking and activating a base fiber with acid liquor, cleaning, drying, immersing in a calcium source solution and a carbonate solution in sequence for treatment, and then placing in a Tris-HCl buffer solution containing dopamine hydrochloride for reaction to obtain the modified fiber.
  9. 9. The method according to claim 8, wherein the urease is prepared by grinding urease-rich plant seeds into fine powder, adding water, stirring, filtering, centrifuging the obtained filtrate, collecting supernatant as urease, stirring at 600-1200 rpm for 20-40min, and centrifuging at 2500-6000rad/min for 15-25min at 2-8deg.C.
  10. 10. Use of a biomimetic dandelion proppant system as claimed in any one of claims 1-7 in oil and gas exploitation hydraulic fracturing.

Description

Bionic dandelion propping agent system and preparation method and application thereof Technical Field The invention relates to the technical field of oil and gas yield improvement, in particular to a bionic dandelion propping agent system and a preparation method and application thereof. Background Hydraulic fracturing is one of the core technologies for increasing production of oil and gas wells, and is characterized in that high-pressure fracturing fluid is injected into a stratum to enable reservoir rock to form artificial cracks, propping agents are injected into the cracks to prevent the cracks from being closed again under the closing pressure of the stratum, so that an oil and gas seepage channel with high diversion capacity is formed. The properties of the propping agent, such as strength, density and transport capacity, directly affect the effectiveness of the fracturing modification. At present, the total amount of the metal mine tailings piled up in China is huge, more than 160 hundred million tons by 2024 years, and the metal mine tailings are still increased at a speed of more than 14 hundred million tons each year, and mainly come from mines such as iron, copper, gold and the like, wherein the iron tailings account for the highest proportion. The stockpiling of a large amount of tailings not only occupies land resources, but also has important safety and environmental risks such as dam break, heavy metal pollution and the like. Therefore, the method has important practical significance in recycling tailings, and particularly applying the tailings to the field of petroleum exploitation in a large scale and high value. In the prior art, there have been attempts to apply tailings to the preparation of ceramsite proppants. For example, chinese patent application publication No. CN103172349a discloses a proppant made from boron mine tailings, iron mine tailings and soft clay as raw materials by light burning, grinding, mixing, granulating and high temperature sintering. The method utilizes the tailings, but needs high-temperature sintering, has high energy consumption and complex process, and the tailings are only used as auxiliary raw materials, so that the mixing proportion is limited, and the large-scale digestion of the tailings is difficult to realize. The Chinese patent application with the publication number of CN105801162A discloses a preparation method of a sulfur-iron tailing ceramsite proppant, which is prepared by carrying out calcination pretreatment and petroleum drilling waste liquid impregnation on sulfur-iron tailings, and then preparing ceramsite through batching, granulating and sintering. The method also has the problems of high-temperature sintering, high energy consumption and complex process. The Chinese patent with the publication number of CN107011886B discloses a method for preparing a ceramsite proppant from bauxite tailings, which comprises the steps of magnetic separation for iron removal, presintering, proportioning, crushing, granulating and sintering. In addition, the compressive strength of the tailing materials is generally low, if the tailing materials are directly used as propping agents without special treatment, the tailing materials are easy to break under high closing pressure, and the fracture conductivity is obviously reduced. Meanwhile, the density of the tailing materials is high, the transportation performance in the fracturing fluid is poor, and effective filling of the far ends of the cracks is difficult to form. Therefore, the development of a proppant preparation technology which can take tailings as a main matrix, does not need high-temperature sintering, has low cost and can effectively solve the problems of low strength and poor transportation of tailings propping agents is needed in the field so as to realize the dual purposes of large-scale high-value utilization of tailings and oil gas yield increase. Disclosure of Invention The invention aims to provide a bionic dandelion propping agent system and a preparation method and application thereof, so as to solve the problems in the prior art. In order to achieve the above object, the present invention provides the following solutions: The invention provides a bionic dandelion propping agent system, which comprises modified tailing propping agent particles and modified fibers; Wherein the mass ratio of the modified tailing propping agent particles to the modified fibers is 99.9-99 percent, namely 0.1-1 percent; The modified tailing propping agent particles are tailing particles treated by a modified treatment liquid, and the modified treatment liquid comprises urease, urea and a calcium source; The modified fiber is a fiber subjected to surface treatment, and the surface of the modified fiber is loaded with calcium carbonate crystals and a polydopamine layer. Preferably, the tailings particles are selected from one or more of iron tailings, copper tailings, lead tailings, zinc tailings, nickel taili