Abstract: The present invention belongs to the technical field of oil well cement preparation, and discloses a long-term high-temperature resistant and toughened well cementing and silica-cement composite material and a preparation method. A solid component comprises cement, alumina, superfine high-purity silica sand, a suspending agent and a toughening material according to weight fractions; the toughening material comprises a latex fiber toughening agent and a nano graphene sheet; and a liquid component is composed of water, nano iron oxide and an oil well cement admixture according to weight fractions. Cement slurry with a ratio of the present invention can achieve compressive strength reaching up to 31 MPa after being cured under a high-temperature and high-pressure environment of 200° C. and 150 MPa for one year; and the gas permeability is controlled below 0.02 mD.

Abstract: The invention provides a collaborative optimization method for gas injection huff-n-puff parameters in tight oil reservoirs. The method relates to the technical field of oilfield development parameter optimization, including: (1) establishing the numerical simulation model that accurately describes the actual oil reservoirs; (2) determining the optimization parameters of gas injection huff-n-puff, giving the optimization range of gas injection huff-n-puff parameters and other variable constraints, and establishing an optimization objective function; and (3) using the particle swarm optimization algorithm to solve the objective function constructed based on a collaborative optimization model for gas injection huff-n-puff parameters. Then the optimal gas injection rate, gas injection time, soaking time, and production time after the collaborative optimization for gas injection huff-n-puff parameters of the reservoir are obtained.

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: Some embodiments of the present disclosure provide a method for preparing a self-phase change proppant based on an emulsified and toughened bio-based epoxy resin. Toughening modification is performed on the bio-based epoxy resin by graphite particles, and then the bio-based epoxy resin after the toughening modification is emulsified by SiO2 particles as an emulsifier to prepare the self-phase change proppant; a proportion of different mesh numbers in the self-phase change proppant is adjusted by changing a concentration of the emulsifier during emulsification; and the chemical formula of the bio-based epoxy resin is: The proppant particles in the present disclosure have good sphericity and high fracture permeability after being laid, which can effectively extract the remaining oil in the fractures, thus improving the development efficiency of the oilfield.

Abstract: A method, a system, and a device for full-waveform inversion deghosting for a marine variable depth streamer data acquisition are provided for solving existing problems that deghosted seismic data has low accuracy and is accompanied by artifacts due to a large error in ghost prediction. The provided method includes: acquiring seismic data, jointly solving Lippmann-Schwinger equations to obtain normal derivatives of an incident wave field and a wave field of a receiver surface, performing a wave field extrapolation by a Kirchhoff equation that includes only an integral on the receiver surface to obtain a wave field of a sea surface recorded by a horizontal streamer, calculating a ghost operator, and subjecting the ghosted wave field of the sea surface recorded by the horizontal streamer to full-waveform inversion deghosting to obtain deghosted seismic data. The provided method improves the accuracy and signal-to-noise ratio (SNR) of deghosted seismic data.

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 pressure compensation device with an accumulator group for controlled pressure drilling includes an electrical flat valve, a check valve, an accumulator group, a flanged pup joint and a support base. The electrical flat valve is connected to the check valve and is mounted on a top surface of the support base. The accumulator group mounted on the whole support base is a pre-storage pressure compensation device for controlled pressure drilling, and is located at a downstream position of the check valve. The liquid inlet end of the accumulator group is connected to the check valve, and the liquid discharge end is connected to the flanged pup joint.

Abstract: A method for evaluating rock drillability by a nano-indentation test on a rock cutting includes: conducting a nano-indentation test on a rock cutting sample, acquiring a displacement-load curve of an indenter, and calculating a micro-hardness under the nano-indentation test; calculating mineral composition of the rock cutting sample based on a statistical distribution characteristic of the micro-hardness, and transforming the micro-hardness under the nano-indentation test on the rock cutting sample into a macro-hardness; and calculating a rock drillability grade characterized by the micro-hardness under the nano-indentation test on the rock cutting sample based on a correlation between the macro-hardness of the rock cutting sample and the rock drillability grade. In the context of few downhole rock samples and high cost, the method overcomes the limitation of sample size and shape on conventional testing and solves the difficult problem of mechanical parameter testing of deep rocks.

Abstract: The present invention relates to a target-oriented seismic acquisition method and apparatus, a medium and a device. The target-oriented seismic acquisition method comprises the steps of: giving parameters of an initial velocity model and a three-dimensional seismic layout aiming to an underground target position; conducting wave field continuation and focusing analysis on the three-dimensional seismic layout, and calculating distribution of seismic energy on the ground in an underground target region; conducting normalization processing on distribution of the seismic energy on the ground, and then conducting level partitioning to obtain a primary energy region and a secondary energy region; adding the number of shot points in the primary energy region to achieve target-oriented acquisition, and obtaining a target-oriented inhomogeneous laying acquired data imaging result.

Abstract: The invention discloses a method for determining vertical well stratified fracturing crack length based on interlayer equilibrium development. According to the method, interlayer equilibrium development can be achieved by determining the crack length of fracturing of each layer in the condition that an oil well meets the productivity requirements. The method comprises the following steps: 1) a threshold pressure gradient of each layer is determined; 2) a relationship chart of the crack half-length xf and the equivalent well diameter rwe is established; 3) daily oil production rate per unit thickness Qc meeting the production requirements is calculated; 4) the equivalent well diameter rwe of each layer is calculated according to the daily oil production rate Qc; and 5) the crack half-length xf of fracturing of each layer is calculated according to the equivalent well diameter rwe of each layer.

Abstract: A sinusoidal corrugated tube-type spiral wounded heat exchanger suitable for FLNG, wherein a top of an outer cylinder has a shell-side refrigerant inlet and a bottom thereof has a shell-side refrigerant outlet; a sinusoidal corrugated tube-type liquid distributor is below the shell-side refrigerant inlet, a first sinusoidal corrugated winding tube bundle and a second sinusoidal corrugated winding tube bundle, which are heat exchanger tubes with a sinusoidal wave shape, are inside the outer cylinder, and peaks and troughs of the first sinusoidal corrugated winding tube bundle and the second sinusoidal corrugated winding tube bundle are in staggered correspondence one by one from top to bottom; a sinusoidal corrugated tube-type liquid distributor includes a one-into-two-type tube, a two-into-four-type tube, two sinusoidal corrugated tube-type liquid distribution tubes from top to bottom.

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: The present disclosure belongs to the technical field of seismic exploration imaging, and relates to an interpretive-guided velocity modeling seismic imaging method and system, a medium and a device. The method comprises the following steps: S1. performing first imaging on a given initial velocity model to obtain a first imaging result; S2. performing relative wave impedance inversion on the first imaging result to obtain a relative wave impedance profile; S3. performing Curvelet filtering on the relative wave impedance profile to obtain a first interpretation scheme; S4. superposing the first interpretation scheme and the initial velocity model to obtain a new migration velocity field; S5. performing second imaging on a new migration velocity field to obtain a second imaging result; and S6. repeating steps S2-S4 for the obtained second imaging result until a final seismic imaging result is obtained.

Abstract: The present disclosure relates to the technical field of oil-gas field development, and discloses a shale oil fracturing synchronous energizing simulation experimental device and method. The shale oil fracturing synchronous energizing simulation experimental device comprises a liquid supply system, a confining pressure loading system, a fracturing system, an energizing system and a recovery system, wherein the liquid supply system is used for storing fluid and can inject the fluid into the fracturing system; the fracturing system can bear a test piece, receive the fluid injected by the liquid supply system and serve as seepage space of the fluid; the confining pressure loading system is used for providing simulated confining pressure for the test piece; the energizing system is used for simulating an energizing effect on a test piece after fracturing liquid is injected; and the recovery system is used for collecting discharged liquid and separating and metering the discharged liquid.

Abstract: A deepwater subsea coiled tubing drilling rig includes a lifting rack having an upper rack and a lower rack which are sleeved with each other and connected by a lifting device. A working space is enclosed by the upper rack and the lower rack, and an underwater connecting and disconnecting tool is installed in the working space; the working space is transformed between a high-position large-space state for connecting and disconnecting through the tool and a low-position small-space state for the drilling process, along with the up-down movement of the upper rack. The upper rack is provided with an underwater coiled tubing system used for lowering and lifting a downhole tool combination, and the lower rack is provided with a wellhead device.

Abstract: The present disclosure belongs to the technical field of seismic exploration imaging, and relates to an interpretive-guided velocity modeling seismic imaging method and system, a medium and a device. The method comprises the following steps: S1. performing first imaging on a given initial velocity model to obtain a first imaging result; S2. performing relative wave impedance inversion on the first imaging result to obtain a relative wave impedance profile; S3. performing Curvelet filtering on the relative wave impedance profile to obtain a first interpretation scheme; S4. superposing the first interpretation scheme and the initial velocity model to obtain a new migration velocity field; S5. performing second imaging on a new migration velocity field to obtain a second imaging result; and S6. repeating steps S2-S4 for the obtained second imaging result until a final seismic imaging result is obtained.

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 separation device with two-stage gas-liquid mixture and conical spiral fields is provided. A first-stage uniform mixer performs first-stage gas-liquid crushing and uniform mixing process by an outer micropore ceramic pipe, a middle micropore ceramic pipe and an inner micropore ceramic pipe and crushes large bubbles in the gas-liquid two-phase flow into small bubbles. A second-stage uniform mixer performs second-stage gas-liquid crushing and uniform mixing process. A whirlpool-making gas collector adjusts the gas-liquid uniform mixing flow obtained after two-stage gas-liquid uniform mixing into hollow-core type high-speed two-phase spiral flow. A conical degasser performs gas-liquid efficient separation operation in a high-speed conical spiral field.

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.