Abstract: A preparation method of the microcapsules for low-temperature well cementation to be used to control cement hydration heat includes: (S1) a shell material, and added into deionized water, then the resultant mixture being stirred in a thermostat water bath so as to completely dissolve it into a homogeneous and stable shell material solution; (S2) a core material and an emulsifier being put into a three-necked flask and stirred in a thermostat water bath so as to uniformly emulsify and disperse them, forming a stable oil-in-water core material emulsion, while adjusting the pH value of the emulsion with a pH adjuster; (S3) the three-necked flask containing the core material emulsion being transferred to a water bath, and then the shell material solution being dropwise added into it with stirring, after reacting, a solid-liquid mixture being poured out so as to naturally cool it to room temperature.

Abstract: Provided in the present application is a preparation method for a double-layer osteochondral tissue repair stent, comprising: formulating a first feed solution, the first feed solution comprising recombinant collagen, sodium hyaluronate, and hydroxyapatite; formulating a second feed solution, the second feed solution comprising recombinant collagen and sodium hyaluronate; freeze-drying the first feed solution and the second feed solution and forming a gel-like double-layer structure; and adding the gel-like double-layer structure into a crosslinking agent for crosslinking. The present method also relates to a double-layer osteochondral tissue repair stent, comprising: a first layer composed of raw materials including recombinant collagen, sodium hyaluronate, and hydroxyapatite; and a second layer composed of raw materials including recombinant collagen and sodium hyaluronate.

Abstract: The present invention relates to a process for preparing a metal-chelate retarder by a sol-gel method. The method comprises the following steps: weighing calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and ferric nitrate nonahydrate according to a certain mass ratio and adding them into deionized water; placing the mixed solution on a magnetic stirrer and stirring the mixed solution evenly; adding citric acid monohydrate or gluconic acid, ethylene glycol or glycerol, and placing the mixed solution into a water bath to react to obtain the metal-chelate retarder. The process of the present invention has a reliable principle, overcomes the defects of long production period, complex preparation and the like of the existing retarders, has the advantages of simple process operation, cheap and easily available raw materials, and short production period.

Abstract: A preparation method of the microcapsules for low-temperature well cementation to be used to control cement hydration heat includes: (S1) a shell material, and added into deionized water, then the resultant mixture being stirred in a thermostat water bath so as to completely dissolve it into a homogeneous and stable shell material solution; (S2) a core material and an emulsifier being put into a three-necked flask and stirred in a thermostat water bath so as to uniformly emulsify and disperse them, forming a stable oil-in-water core material emulsion, while adjusting the pH value of the emulsion with a pH adjuster; (S3) the three-necked flask containing the core material emulsion being transferred to a water bath, and then the shell material solution being dropwise added into it with stirring, after reacting, a solid-liquid mixture being poured out so as to naturally cool it to room temperature.

Abstract: An oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings is provided. The high-temperature suspension stabilizer is reasonable in principle, inexpensive and easily available in raw materials, high in product uniformity and good in chemical stability. Meanwhile, waste is changed into wealth. Therefore, the high-temperature suspension stabilizer is environment-friendly and has a broad industrial application prospect.

Abstract: A well cementation working solution prepared from red mud, slag and waste drilling fluids. The working solution is prepared from the following components in parts by weight: 100 parts of waste drilling fluids, 50-100 parts of slag, 5-50 parts of red mud, 4-7 parts of a suspension stabilizer, 1-7 parts of an activating aid, 0.5-5 parts of an anti-pollution agent and 0.4-3.5 parts of a diluent. The waste drilling fluids are waste waterborne drilling fluids. The slag is blast furnace slag or vanadium-titanium slag. The suspension stabilizer is sodium bentonite, carboxymethyl cellulose or a mixture of sodium bentonite and carboxymethyl cellulose. The activating aid is sodium metasilicate nonahydrate, sodium carbonate or a mixture of sodium metasilicate nonahydrate and sodium carbonate. The anti-pollution agent is sodium salicylate, potassium citrate or a mixture of sodium salicylate and potassium citrate. The diluent is sodium lignin sulfonate.

Abstract: The present invention relates to a process for preparing a metal-chelate retarder by a sol-gel method. The method comprises the following steps: weighing calcium nitrate tetrahydrate, aluminum nitrate nonahydrate and ferric nitrate nonahydrate according to a certain mass ratio and adding them into deionized water; placing the mixed solution on a magnetic stirrer and stirring the mixed solution evenly; adding citric acid monohydrate or gluconic acid, ethylene glycol or glycerol, and placing the mixed solution into a water bath to react to obtain the metal-chelate retarder. The process of the present invention has a reliable principle, overcomes the defects of long production period, complex preparation and the like of the existing retarders, has the advantages of simple process operation, cheap and easily available raw materials, and short production period.

Abstract: A method for evaluating the breakage strength of first and second cemented surfaces of well cementation under a dynamic load, includes: producing a rock-set cement-casing composite structure sample; clamping the sample between an incident rod and an output rod of a Hopkinson rod, hitting the incident rod with a conical punch to generate incident waves, enabling the incident waves to pass through the sample to generate reflected waves and projected waves, recording dynamic strain signals of incident waves, reflected waves and projected waves, and converting the dynamic strain signals into electrical signals and transmitting the electrical signals to a computer; recording the process and the corresponding time point from breakage starting to a complete breakage of the first and second cemented surfaces by a photographic instrument; obtaining a strain rate time travel curve and a stress-strain curve, and obtaining the corresponding breakage strength by analyzing the curve peak points.

Abstract: An oil well cement slurry high-temperature suspension stabilizer prepared from oil-based shale drilling cuttings is provided. The high-temperature suspension stabilizer is reasonable in principle, inexpensive and easily available in raw materials, high in product uniformity and good in chemical stability. Meanwhile, waste is changed into wealth. Therefore, the high-temperature suspension stabilizer is environment-friendly and has a broad industrial application prospect.

Abstract: A well cementation working solution prepared from red mud, slag and waste drilling fluids. The working solution is prepared from the following components in parts by weight: 100 parts of waste drilling fluids, 50-100 parts of slag, 5-50 parts of red mud, 4-7 parts of a suspension stabilizer, 1-7 parts of an activating aid, 0.5-5 parts of an anti-pollution agent and 0.4-3.5 parts of a diluent. The waste drilling fluids are waste waterborne drilling fluids. The slag is blast furnace slag or vanadium-titanium slag. The suspension stabilizer is sodium bentonite, carboxymethyl cellulose or a mixture of sodium bentonite and carboxymethyl cellulose. The activating aid is sodium metasilicate nonahydrate, sodium carbonate or a mixture of sodium metasilicate nonahydrate and sodium carbonate. The anti-pollution agent is sodium salicylate, potassium citrate or a mixture of sodium salicylate and potassium citrate. The diluent is sodium lignin sulfonate.

Abstract: A method for evaluating the breakage strength of first and second cemented surfaces of well cementation under a dynamic load, includes: producing a rock-set cement-casing composite structure sample; clamping the sample between an incident rod and an output rod of a Hopkinson rod, hitting the incident rod with a conical punch to generate incident waves, enabling the incident waves to pass through the sample to generate reflected waves and projected waves, recording dynamic strain signals of incident waves, reflected waves and projected waves, and converting the dynamic strain signals into electrical signals and transmitting the electrical signals to a computer; recording the process and the corresponding time point from breakage starting to a complete breakage of the first and second cemented surfaces by a photographic instrument; obtaining a strain rate time travel curve and a stress-strain curve, and obtaining the corresponding breakage strength by analyzing the curve peak points.