Pdc Bit Drilling Parameters Optimization Models And Their Applications

The process of optimization of drilling parameters includes the instantaneous and average drilling rate, the rotary footage and the bit's rotary time in the bottom hole etc. So it is necessary to establish the mathematical model of optimization for drilling parameters, which agrees with the drilling conditions. To represent new developments in this realm, we have undertaken some synthetical and thorough researches to these questions.Firstly, we studied the theoretical basis of optimization of the routine parameters, including Bodgem's, Younger's, Maldera's and Olhary's optimization patters with dimensionless drilling parameters, Lagrange's multiplication factor method and the method of using the release of WOB to determine the parameters concerned with multiple drilling patter.Together with the direction of study of dynamic drilling tools combining optimization of the bit parameters, we systematically studied the theoretical and practical operating characters, the optimization matching, the rotary characters and the attended items at use of the screw and the turbodrill. Regarding the drilling rate patter as the objective function and by studying the basic theories, we have established the mathematical patter to optimize parameters of the optimal WOB, rotary speed, pressure drop, waterpower and the drilling rate, and given out the method to optimize parameters when the roller bit, PCD bit and the dynamic drilling tool were used together. To reflect the actuality on the spot betterly, we put forward the method of determining the optimal parameters by using the MBP curves and the mathematical patter of the minimum drilling cost by using the iterative method. It allows for the optimization of both single bit and multiple bits of all well. The result indicates that: by adopting this method, it could save over 25-40% of the drilling costs and it's a effective method to select the type of the bit and to determine the quantity of the bits needed reasonably.On the basis of collecting multiple data and together with the actuality in Daqing-oilfield, we analyzed the effect of single factor on the drilling speed and cost, and studied the abrasive regulation of the bit. Then we obtained some conclusions and recognitions more suitable for actuality on the site.