Design Of Automatic Power Tong For Workover And Simulation Of Its Hydraulic System

Workover operations is the necessary measures to maintain the the normal production of wells and injection wells as scheduled.For tubing, sucker rods, packer and other downhole tools,making-up or breaking-out their screws and then putting them down into or pulling them out from the oil well is an important workover operation.And at present, this operation is mainly completed by workers pushing or pulling the opened head hydraulic tongs and switching two elevators. The disadvantages of technique used now are as follows: low operating efficiency, labor-intensive, poor safety, as well as causing serious environmental pollution and so on. Thus, to solve these problems, the design of a new automatic power tong for workover operations will make great significance.In this paper, researching the development situation of power tongs used in oil field both at home and abroad in-depth and extensive range, comparing the advantages and disadvantages of different structural design, analysing the operation flow of installation and dismantlement of pipes during an oil well workover job, and put forward a new type of automatic power tong system program for workover operations. The new plan integrates both closed head tongs and power slip together, enabling that workers could operate away from the wellhead, realizing the automatic and environmentally friendly operations, could clamping a large range in both positive and the contrary direction without replacing any parts, chucking performance well, operating efficiently. Design of the new automatic power tong for workover operations has applied for and won the National Invention Patent.In this paper, it introduce the design of main tong, back-up tong, and power slip- the three parts of the power tong concretely, developed the schematics of its hydraulic system, and use AMESim engineering simulation software set up the hydraulic system model of the main tong and the lifting system of the back-up tong respectively. The dynamic simulation analysis of the system provides a number of static and dynamic characteristic curve, and then gave some solutions methods to the problems found by analyzing the curve. The curve also provides a theoretical reference for the actual structures of the hydraulic system.