Abstract: An intra-layer reinforcement method, and a consolidation and reconstruction simulation experiment system and an evaluation method for a gas hydrate formation are provided. In the intra-layer reinforcement method, the formation reconstruction and fracturing grouting reinforcement technologies are combined; a fracturing grouting process is adopted to create fractures in the gas hydrate formation; and a consolidation liquid enters the fractures and penetrates into the formation through a pressure difference to form a reinforcement with a ribbed slab structure and a specified strength and permeability, which supports the formation to achieve collapse prevention and sand prevention.

Abstract: An oil well cement composite permeation enhancement agent suitable for a hydrate layer and a preparation method thereof are disclosed. In parts by weight, the composition of raw materials of the composite permeation enhancement agent is 4.6 parts-5.0 parts of kerosene, 0.23 parts-0.25 parts of emulsifier, 0.8 parts-1.1 parts of modified polypropylene fiber, 10.0 parts-12.0 parts of porous and permeable microspheres, 1.0 part-1.2 parts of paraffin, and 57.5 parts-62.5 parts of water. The composite permeation enhancement agent can effectively improve the permeability of the cement stone which reshapes the formation framework and increase the mining rate of hydrate. The oil well cement composite permeation enhancement agent has the advantages of long-term performance, low cost, and green environmental protection.

Abstract: A geopolymer cementing fluid with controllable thickening time includes the following components in parts by weight: 100 parts of a cementitious material, 10 parts-30 parts of an activator, 0.2 parts-5 parts of a retarder, 0.4 parts-4 parts of an anti-settling agent, and 30 parts-70 parts of water. The geopolymer cementing fluid of the present invention has the advantages of controllable thickening time, excellent compressive strength, good settlement stability, good rheological properties, green and eco-friendly, and the like. The geopolymer cementing fluid can be better suited for the operations of oil and gas well cementing and ensure cementing safety.

Abstract: A scour-resistant interface enhancer, a preparation method, and an application thereof are provided. The scour-resistant interface enhancer is a compound solution prepared by using a 0.1% surfactant CAEO-15 and a 0.3% silane coupling agent as solutes and using clear water and absolute ethanol as solvents, where the mass ratio of clear water to absolute ethanol is 9:1. The scour-resistant interface enhancer of the present invention used as pre-flush for well cementing of coalbed methane wells has good wettability modification effect, shows scour-resistant effect against cement slurry, exhibits good compatibility with cement slurry system, and can significantly improve the cementing strength and air tightness of two interfaces of coal bed and effectively enhance the cementing quality of coalbed methane wells.

Abstract: An oil well cement composite permeation enhancement agent suitable for a hydrate layer and a preparation method thereof are disclosed. In parts by weight, the composition of raw materials of the composite permeation enhancement agent is 4.6 parts-5.0 parts of kerosene, 0.23 parts-0.25 parts of emulsifier, 0.8 parts-1.1 parts of modified polypropylene fiber, 10.0 parts-12.0 parts of porous and permeable microspheres, 1.0 part-1.2 parts of paraffin, and 57.5 parts-62.5 parts of water. The composite permeation enhancement agent can effectively improve the permeability of the cement stone which reshapes the formation framework and increase the mining rate of hydrate. The oil well cement composite permeation enhancement agent has the advantages of long-term performance, low cost, and green environmental protection.

Abstract: A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

Abstract: A geopolymer cementing fluid with controllable thickening time includes the following components in parts by weight: 100 parts of a cementitious material, 10 parts-30 parts of an activator, 0.2 parts-5 parts of a retarder, 0.4 parts-4 parts of an anti-settling agent, and 30 parts-70 parts of water. The geopolymer cementing fluid of the present invention has the advantages of controllable thickening time, excellent compressive strength, good settlement stability, good rheological properties, green and eco-friendly, and the like. The geopolymer cementing fluid can be better suited for the operations of oil and gas well cementing and ensure cementing safety.

Abstract: A scour-resistant interface enhancer, a preparation method, and an application thereof are provided. The scour-resistant interface enhancer is a compound solution prepared by using a 0.1% surfactant CAEO-15 and a 0.3% silane coupling agent as solutes and using clear water and absolute ethanol as solvents, where the mass ratio of clear water to absolute ethanol is 9:1. The scour-resistant interface enhancer of the present invention used as pre-flush for well cementing of coalbed methane wells has good wettability modification effect, shows scour-resistant effect against cement slurry, exhibits good compatibility with cement slurry system, and can significantly improve the cementing strength and air tightness of two interfaces of coal bed and effectively enhance the cementing quality of coalbed methane wells.

Abstract: A high-strength geopolymer hollow microsphere, a preparation method thereof and a phase change energy storage microsphere are provided, including: dissolving sodium hydroxide, sodium silicate and spheroidizing aid in water to form a solution A, and adding active powder to the solution A, stirring and uniformly mixing to form a slurry B, adding the slurry B to an oil phase, stirring and dispersing into balls, filtering to obtain geopolymer microspheres I, washing the geopolymer microspheres I, and then carrying out a high-temperature calcination to obtain the high-strength geopolymer hollow microspheres II; using the high-strength geopolymer hollow microsphere as a carrier, absorbing a phase change material into the carrier, and mixing a microsphere carrying the phase change material with an epoxy resin, adding a powder dispersant and stirring to disperse the microsphere, after the epoxy resin is solidified, screening the superfluous powder dispersant to obtain the phase energy storage microsphere.

Abstract: A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

Abstract: An intra-layer reinforcement method, and a consolidation and reconstruction simulation experiment system and an evaluation method for a gas hydrate formation are provided. In the intra-layer reinforcement method, the formation reconstruction and fracturing grouting reinforcement technologies are combined; a fracturing grouting process is adopted to create fractures in the gas hydrate formation; and a consolidation liquid enters the fractures and penetrates into the formation through a pressure difference to form a reinforcement with a ribbed slab structure and a specified strength and permeability, which supports the formation to achieve collapse prevention and sand prevention.

Abstract: A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

Abstract: A performance evaluation device and a design method of a cement for well cementing in a penetrated hydrate layer are provided. The performance evaluation device includes an equivalent wellbore, an inner circulation system, an outer circulation system, a thermal insulation cover, a bracket, a temperature sensing system, and a cement mold. The device can simulate a true downhole situation, conduct an evaluation experiment on the heat insulation performance of a cementing cement, and conduct experiments at different temperatures with automatic temperature control. The design method is to use a low-hydration, early-strength, and heat-insulating cement slurry system during the well cementing in a penetrated hydrate layer, where the low-hydration and early-strength characteristics ensure the effective sealing of a hydrate layer during a cementing process, and the heat insulation characteristic results in low heat conductivity and thus can ensure the stability of a hydrate layer during a production operation.

Abstract: A high-strength geopolymer hollow microsphere, a preparation method thereof and a phase change energy storage microsphere are provided, including: dissolving sodium hydroxide, sodium silicate and spheroidizing aid in water to form a solution A, and adding active powder to the solution A, stirring and uniformly mixing to form a slurry B, adding the slurry B to an oil phase, stirring and dispersing into balls, filtering to obtain geopolymer microspheres I, washing the geopolymer microspheres I, and then carrying out a high-temperature calcination to obtain the high-strength geopolymer hollow microspheres II; using the high-strength geopolymer hollow microsphere as a carrier, absorbing a phase change material into the carrier, and mixing a microsphere carrying the phase change material with an epoxy resin, adding a powder dispersant and stirring to disperse the microsphere, after the epoxy resin is solidified, screening the superfluous powder dispersant to obtain the phase energy storage microsphere.