Research On Key Technologies Of Modular Derrick For 3000m Electric Top Drive Drilling Rig

The new generation of top-drive rigs can reach a depth of 3 000 m,which solves the urgent need for high-performance rigs for drilling deep and complex formations.As an important part of the rig,derricks are used to carry composite loads in the exploration work and are also used to place overhead cranes,cruise and other equipment.At present,the common derrick is mainly installed at a low level,and the overall lifting is inconvenient for transportation.In order to improve the efficiency of the new drilling rig,this article designs a new type with a small floor area,lifting and saving space,suitable for hills and mountains,and low transportation costs for derrick,use ANSYS Workbench finite element analysis software to perform static analysis,dynamic analysis,and stability analysis on the designed derrick to verify the reliability of derrick structure design.The main research contents are as follows:(1)the new derrick is built on the advantages of the K-type derrick,and it is improved to a vertical lifting modular derrick.The derrick design meets API Spec 4F "Specifications for drilling and work over derricks and foundations" and other specifications.The main body and accessories are designed,and the derrick lifting and connection methods determine at the same time.(2)perform a static analysis of the derrick.Identify the different working conditions of the derrick,and apply the load at its corresponding position to get the stress and strain results under different working conditions of the derrick.The analysis results show that the stress safety factor of the derrick under each working condition is greater than the API standard requirements and meet strength requirements.(3)perform dynamic analysis of the derrick.The derrick modal analysis yields the first ten orders of frequencies and self-vibration modes.The rotating speed of the rotating equipment during debugging is set to avoid the danger of resonance.Using the complete method to accomplish the harmonic response analysis,the derrick can avoid dangerous frequencies.Overcoming resonance;when the derrick is performingtransient dynamic analysis,coupled with the wind load based on the impact load applied by the derrick,the response results are as follows: there is system damping in the derrick structure itself,which causes delay in transient vibration response and vibration amplitude.The derrick has the ability to resist shock loads during changes during fluctuations.(4)according to the stability theory conversion of the whole derrick,the stability stress of the whole structure is lower than the allowable stress of the derrick material,and the overall stability of the derrick complies with the use requirements.Through the finite element analysis,the critical load of the derrick instability is greater than the maximum load on the top of the derrick.The two methods proved that the derrick has favorable performance of stability.The analysis results show that the rigidity,strength and overall stability of the new developed derrick meet the requirements of safety design,reliable performance and wide application prospects.