| Since the advent of PDC bit in the 1980s,it has gradually become an efficient rock breaking tool widely popularized and applied in the oil and gas industry due to its high average mechanical drilling speed,large footage and long service life compared with the widely used roller bits at that time.With the continuous progress and development,the production technology of the new generation of PDC bits has been continuously improved and their use has increased year by year.As the main tool for drilling rock breaking,PDC bit's rock breaking efficiency directly affects the drilling efficiency,quality and cost.Among them,the hydraulic performance of the drill bit mainly determines the cooling effect of the cutting tooth surface of the drill bit and the rock-carrying cleaning ability at the bottom of the well.Through the analysis of the flow field at the bottom of the PDC bit,the hydraulic structure of the drill bit can be better optimized,and the hydraulic energy can be fully utilized to enhance the rock-breaking efficiency of the drill bit at the bottom of the well and the cleaning effect of mud at the bottom of the well,so as to obtain a more efficient production capacity.At present,all PDC bit manufacturers have begun to simulate and analyze the hydraulic structure design of PDC bits in an attempt to optimize the hydraulic design of the bits.However,most manufacturers'analysis methods are complicated,and the software society is difficult,the operation process is complicated,and the analysis efficiency is low.In order to improve the efficiency of simulation analysis of bit hydraulic design and reduce the threshold of hydraulic software,this paper will investigate the PDC bit hydraulic design technology and efficiency.Based on the existing PDC bit downhole flow field simulation technology,this paper has carried out the following research on the numerical simulation of PDC bit downhole conditions,as well as the inheritance and development of simulation technology:(1)Establish the criteria for judging the cooling effect of hydraulic design on PDC bit cutting teeth.The thermal wear mechanism and temperature distribution of the cutting teeth of the existing PDC bit are studied to further simplify the heating and heat transfer model of the cutting teeth while working,and the factors of heat dissipation of the cutting teeth are added during the numerical simulation analysis of the flow field at the bottom of the well,and taken the temperature cooling effect of the cutting tooth surface as the criterion for evaluating the cooling effect of PDC bit cutting tooth.(2)Based on the Web,a PDC bit bottom hole flow field simulation platform suitable for the company's actual situation is established.Integrate the company's existing hydraulic design techniques,and establish a set of technical means that can be more convenient and simple to simulate in different environments and conditions,so as to reduce the work pressure in production design and improve the company's Labor cost pressure.(3)Application of PDC bit bottom flow simulation platform.Based on the performance of hydraulic design on bit cooling and rock carrying in research on PDC bit bottom flow field simulation platform,and the analysis and application of the hydraulic structure of the coring PDC bit,the field results show that the coring effect and working efficiency of the improved design have good performance.The experiment shows that the simulation platform of PDC bit bottom-hole flow field Developed in this paper,it simplifies the complex operation and setting process of traditional numerical simulation analysis software,improves analysis efficiency and saves labor costs.PDC bit bottom flow field simulation platform is not only suitable for conventional PDC bit,but also suitable for personalized design PDC bit,which has strong versatility and use value. |
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