Research On The Real-time Evaluation Of The Rock Breaking Efficiency Of The Drill Bit And The Optimization Of The Drill Bit

The rock breaking efficiency of drill bit directly determines the drilling cycle and drilling cost.The rock breaking efficiency of drill bit is also an important basis for drilling rate prediction,drilling parameter optimization,bit wear prediction and bit selection.Therefore,real-time evaluation of bit rock-breaking efficiency is helpful to achieve the goals of real-time prediction of drilling speed,real-time optimization of drilling parameters,real-time prediction of bit wear and real-time optimization of bit.there have the following problems:(1)traditional methods for predicting bit wear cannot achieve real-time and accurate prediction while drilling,and have strong regional characteristics;(2)the traditional real-time optimization drilling target is the drilling rate of the machine,but it cannot achieve the optimization of the pump displacement and compared with the drilling rate of the machine,the factors that can be considered by the machine are more comprehensive and more suitable for the goal of real-time optimization drilling;(3)the traditional real-time bit optimization method is based on rock drillability.In the well area with a large amount of real drilling data,the drill bit optimization based on real drilling data has a higher accuracy.Real-time optimization method for traditional drilling parameters and drilling real-time optimization method of this paper carried out the following research:(1)through the research on theory of mechanical than can choose to mechanical than can be used as drilling real-time evaluation of rock fragmentation efficiency tools,use JL26 data of JL26 Wells 3675 m-3880-m interval and JL wellblock 3 mouth horizontal section of the drill bit rock fragmentation efficiency evaluation,and selected according to the results of the mechanical than can evaluate JL wellblock horizontal section is the most suitable type of bit.Based on the mechanical specific energy theory,the cumulative mechanical specific energy prediction model of drill bit wear was established.First,the cumulative mechanical specific energy prediction of drill bit wear was verified.The results show that the cumulative mechanical specific energy model can accurately predict the complete wear of the cone bit and PDC bit.Reuse bit using the data of the same type of rock bit and PDC bit are cumulative mechanical than can model fitting and bit wear,the last of the accumulation of fitting to establish mechanical model than can and bit wear for validation,the validation results show that the fitting model of cone bit rate was 85.12%,PCD bit fitting model accuracy of 83.56%,can realize real-time accurate predicting the amount of bit wear to fulfill the requirements of the field use.(2)through the research on the factors affecting the mechanical drilling rate,including the drilling pressure,rotating speed,pump displacement,the drilling rate equation of formation coefficient and tooth wear,and through drilled data using the method of undetermined coefficients determined the JL wellblock of related parameters of drilling rate equation based on the drilling rate equation is established to 4224 m4404-m JL02 well hole drilling rate prediction,prediction accuracy is 86.3%,the results show that the established the drilling rate equation of drilling rate forecast real time accurately.The drilling rate equation is put into the hydraulic mechanical specific energy model,and the derivation of the hydraulic mechanical specific energy model is made for the bit pressure,rotation speed and pump displacement respectively,so as to solve the optimal bit pressure,rotation speed and pump displacement.(3)based on the research of the theory of support vector machine(SVM)algorithm,combined with JL wellblock logging and logging data and bit use effect,logging,logging and drilling is established using effect database,support vector machine training,cross validation method is used to determine the model parameters,and finally to JL04 well 4400 m-4470-m hole drill has carried on the optimization,the results showed that the replacement recommended bit after mechanical than can reduce obviously,support vector machine(SVM)method to real-time optimization and the proper bit for the scene to provide reliable drilling bit type selection basis.Write the "drilling real-time evaluation and bit rock fragmentation efficiency optimization" system,using JL24 field comprehensive well logging and mud logging data to test and verify the software,the analysis results are in conformity with the actual,this paper studies the bit rock fragmentation efficiency real-time evaluation and optimization,the real-time prediction and drill bit wear real-time optimization with on-site guidance.