Abstract: Provided is a decision-making method and system for a suspension operation of a marine riser system based on a digital twin, which belongs to the technical field of marine oil and gas development. The decision-making method includes: acquiring original monitoring data by the sensor group to establish a physical entity structure model; acquiring real-time monitoring data to establish a digital twin model of the physical entity structure; and introducing navigation path and speed of the drilling platform, and a configuration and suspension mode of the riser system, combined with the digital twin model of the marine riser coupling system and a limit performance parameter, providing a suspension operation decision-making model of the riser system, and making a real-time accurate suspension operation decision based on a multi-objective optimization algorithm, so as to guarantee a safe and efficient suspension operation of the riser system.

Abstract: The present invention relates to a linkage test apparatus for deepwater drilling riser and hang-off system. The linkage test apparatus includes a motion excitation system, a hang-off system and a riser system. The motion excitation system includes a six-degree-of-freedom excitation platform and sensors. The hang-off system includes a hydraulic cylinder actuating mechanism and a hydraulic system. The hydraulic cylinder in the hydraulic cylinder actuating mechanism is composed of an inner cylinder and an outer cylinder and it is fixed on the six-degree-of-freedom excitation platform by a spider. The inner cylinder of the hydraulic cylinder is hollow. A hang-off joint passes through the center of the inner cylinder, and a bottom of the hang-off joint is connected to the riser system via a rotating flange. The riser system is successively connected by multiple riser test joints, and the bottom is suspended with a lower marine riser package model.

Abstract: A digital processing method of a large or medium-size sand mold includes inverting a three-dimensional CAD model of a mold into a numeric controlling code, putting a prepared sand blank on a hollow grid-shaped processing platform to proceed the digital milling procedure, bringing away waste sand generated during processing by high pressure gas blown out from a nozzle near a cutter and the waste sand entering to a collecting device below the processing platform. A device for carrying out the method is disclosed. The method and the device reduce the processing steps.

Abstract: A digital processing method of a large or medium-size sand mold includes inverting a three-dimensional CAD model of a mold into a numeric controlling code, putting a prepared sand blank on a hollow grid-shaped processing platform to proceed the digital milling procedure, bringing away waste sand generated during processing by high pressure gas blown out from a nozzle near a cutter and the waste sand entering to a collecting device below the processing platform. A device for carrying out the method is disclosed. The method and the device reduce the processing steps.