Research And Design Of Wellhead Equipmentand Safety Control System

With the development of global economy,the world’s demand for the energy sources is becoming more and more increasingly,and the contradiction between supply and demand are also increasingly prominent.China is a country which is vast in territory and rich in resources.The oil resources are very rich.But with the rapid development of the national economy,China’s energy situation has become more and more serious.Demand for oil natural and and gas continues to increase,lead to the exploitation of oil from the land over to the sea and from shallow to deep development with strength gradually increasing.With the exploration and development of oil and gas in China deepening,the geological conditions are becoming more and more complex,which generally have the characteristics of reservoir in deep,high temperature,large output and contains hydrogen sulfide,carbon dioxide acid corrosive gas.Wellhead device is an important equipment on the ground to control the oil well production,which’s performance is related to the safety and efficient production of the oil and gas well.The wellhead safety control system is playing an important role in safety production of high pressure,high yield,high risk of land oil and gas and oil and gas wells on offshore platform.Firstly,this article uses the method of ANSYS finite element analysis to analysis one of main components of oil wellhead-tubing head spool.According to the requirements of the ASME specification,bearing capacity of tubing head spool need to be checked through the third strength theory and the equivalent linearization method so as to find the area of stress concentration of tubing head spool.Secondly,study the method of calculating reliability based on the ANSYS probability analysis,which is the Monte Carlo method and response surface method and several methods of sampling of the Monte Carlo method,and then use the ANSYS/PDS module to calculate reliability of tubing head spool in working condition and obtain its failure probability and reliability index.Thirdly,to achieve the functions of high and low voltage protection,anti-high temperature of fire and the manual shut in a loop,design the hydraulic principle diagram of wellhead safety control system with the requirements of the design of the hydraulic system according to the safety performance of the wellhead.Especially each loop are described in detail.Finally,choose the PLC controller to realize the function of shutting in well automatically through controlling the electromagnetic valve,study on the display function of TD400 C text display in order to achieve alarm function in an emergency situation and the communication function of WinCC software and PLC to achieve real-time display and real-time monitoring of the field data.