Design And Analysis Of Lifting System Of Snubbing Unit

Compared with the traditional work-over operation,snubbing operation has many advantages.It has changed the past operati on mode of shedding flow or circulating pressure under hole by killing fluid,and can be better on protecting the stratum environment and pressure so as to im prove the output capacity of oil and gas and reduces the operational risk.As one of t he core parts of the snubbi ng unit,the structure and strength of the lifting system directly affect the bearing capacity and safety performance of the whole equipment.The im pact and vibration in the operation pro cess will a lso affect the snubbing unit.The synchronization of the lif ting hydraulic cylinder is related to the service life and safety performance of the device.In view of these reason,the design and research of lifting system of snubbing unit have been studied and the contents are expounded as follows.(1)The snubbing technology and its application are introduced.The classification method of the operating device is descri bed.The background,significance and m ain research contents of this paper are illustrated through the study of the current situation of domestic and international.(2)The main structure and the working principle of the lifting system of snubbing unit are introduced in detail.The parameters of the main parts of the lifting system are designed according to the size of load.Because there is u nsupported interval in th e working process,so the unstabl e situation of three different sizes of pipe string under the different well pres sure.According to the different depth of the well,th e corresponding maximum working stroke is obtained,which provides a theoretical basis for field operation.(3)The stress and deformation of the main components of the snubbing unit under various working conditions are analyzed and the results show that all the com ponents of the lifting system meet the strength re quirements.meanwhile,its stability is checked according to th e actual situation when the p iston rod of the lifting hydraulic cylinder rises to the maximum stroke.(4)A brief introduction to the modal ana lysis is given.The f inite element equations of structural dynamics in elastic mechanics and the free vibration equations and eigenvalues of the structure without damping and external loads are introduced.The model simulation of the lifting system of snubbing unit is studied by ANSYS a nd the first ten natural frequencies are calculated.(5)The hydraulic control system of the lifting system is studied,and the hydraulic control loop system is designed in this pape r.The variation of displacement,flow and velocity of hydraulic cylinde r with time was obtained by es tablishing the hydraulic control system.The results show th at the designed circuit meets the requirements of speed and synchronization,which provides a reference for the actual system test.