A Study On Key Techniques For Self-elevating Offshore Platform Supervision System

Self-elevating offshore platform is an offshore engineering equipment for ocean oil and gas exploration which owns many virtues like good working stability and broad developing prospect. Devices on self-elevating offshore platform have characteristics like complicated structure, large number of nodes under supervison, high demands on reliability and etc.Performance of the supervision system plays an important role in platform operation, which affects its stability, safety and reliability. Research work on supervision techniques is a key to realize long-time operation state under complicated ocean climate environments, and it also benefit a lot to found an important base for localization of this kind of ocean oil and gas exploration equipments.Research work in this dissertation focuses on self-elevating offshore platform, studies the corresponding key techniques for its supervision and trys to achieve corresponding solutions. Emulation study combined with model testing was adopted to validate feasibility of the research work. The main contents of this study are as follows.(1) Based on the present situation on self-elevating offshore platform supervision, combined with the present offshore oil and gas exploration situation and domestic needs on energy sources, this dissertation proposed the needs on key techniques investigation aiming at platform supervision.(2) Aiming at solving problems on platform supervision, this dissertation first analyzed structure and functions of self-elevating offshore platform. Based on the analyzed results, supervision parameters of the platform equipments were collected and classified. Demands on platform supervision were analyzed, which includes supervision functions, supervision data transmission and integrated data management of the supervision data.(3) Main methods for self-elevating offshore platform supervision were proposed. The research work involves platform fault diagnosis, control mode of its equipments and management of the supervision data. The fault diagnosis method based on PLC for platform equipments was proposed. Research work on design scheme of the platform equipment control system were carried out, which includes appearance design of control cabinet based on human-machine engineering, and design scheme of touch screen's monitoring interface.(4) Research work on data transmission protocol was done based on the characteristics of self-elevating offshore platform supervision. First, supervision data transmission mode for the platform was analyzed; then, performance of PROFIBUS-DP protocol adopted by the field control layer and IEEE 802.3 protocol adopted by the management layer were investigated. Based on the research work, optimization method for improving performance of the platform was studied.(5) Information integration method for self-elevating offshore platform was studied facing mainly to the field control layer. First, information integration mode for the platform was analyzed; then, design scheme and realization method for protocol converters was presented to integrate heterogeneous devices on the platform adopting different kinds of fieldbus protocols. Gateways between PROFIBUS-DP and Ethernet, CAN and PROFIBUS-DP, HART and PROFIBUS-DP were designed to realize information integration among heterogeneous devices on the platform. Based on the research work, design scheme for constructing a supervision system for the platform was proposed, which adopts two main protocols as PROFIBUS-DP and IEEE 802.3.Testing models designed for platform supervision communication system and elevating system were set up according to results from the former research work on key techniques for self-elevating offshore platform supervision. Results from model testing and analysis have shown effectiveness of the proposed information integration method, which can meet the demands on communication and device operation well.Corresponding research work was carried out by adopting computer simulation and model testing. Key techniques for self-elevating offshore platform supervision presented in this dissertation is suitable for platform operation and can meet domestic needs on domestic offshore oil and gas exploration well. Moreover, it presents an important guidance for practical engineering.