Research Of The Technology Of Offshore Rig Automatic Compensation Based On Winch Drum (AHD, Auto Heave Drum)

The offshore drilling and the land drilling are very different, in this process, the drillingplatform float above the fluctuating ocean, but the drill pipe works in the depth of a fewkilometers of undersea. The offshore drilling platform will have a heave up or downmovement above the sportive waves. This movement has a great negative impact, directlyaffect the position of the down-hole drill bit and drill pressure, reduce the life of the drillingequipment. Therefore, in order to ensure the normal development of the offshore drilling, it isnecessary to adopt the heave compensation system, in order to improve drilling efficiencyand safety. So, we do the work in this article: the research of a technology solution, eliminatethe rig heave caused by floating offshore drilling.In this paper, we design a new rig automatically heave compensation package-based onthe rig winch drum, the package uses a three-phase AC induction motor as the executingagency, turn the winch with the use of a big reduction ratio, winch drum winding or releasewire rope, appropriate compensation speed drill to enhance or decentralization, in order toeliminate the platform heave drilling. Compared with the conventional compensationapparatus, this apparatus having a novel structure is simple, the weight is small, a large rangeof compensation. In the choice of hardware, MRU5hull attitude sensor measurementplatform six degrees of freedom of movement, access the rig heave angle and speed. TheS7-300PLC is designed for the industrial environment, so we use it as a controller. TheSiemens M440inverter is used for speed control to three-phase AC induction motor.In this article, we analysis the platform motions over the ocean in six degrees. Based onthe logical coordinate system, project and conversion, the heaven compute can conspicuouscut down.In the study of the entire system, we design an advanced control algorithm in order toimprove the compensate effect. Because of the three-phase AC induction motor has timevarying and non-linear characters, the conventional algorithm can’t have a good control effect.In this article, we choice the system control with parameter self-setting fuzzy-PID controller, this controller combines the advantages of traditional PID controller and fuzzy controller.Using in the time-varying compensation device, the fuzzy part will work out three suitableparameters according to the error and vary, then it changes the parameters of the PID part. Soit has a high control accuracy and dynamic response performance.According to the PLC controller, introduce the relevant software developers. Use Winccconfiguration software as human-computer interface development tool, the system controlmore intuitive. Use STEP7programming software develop program for S7-300controller.List some control system needed in data processing and controller use ladder diagramprogramming.Finally, we build the experimental platform in the laboratory, do some simplesimulations. A small electrical machine is put inside of the platform, it connect a liner sensor.This equipment imitates the auto heave drum. After analysis the experimental result, we willfind the compensation effect based on the winch drum automatic heave compensation deviceused for drill is good and it is practical.