The Experimental Study Of PDC Bit Drilling Rate Model

The research and application of PDC bit drilling rate model is one of the main tasks ofdrilling engineering. The PDC bit drilling rate is connected with bit structure, lithology,drilling parameters, drilling fluid performance and so on. Establishing a reasonable PDC bitdrilling rate model can predict drilling rate well, and thus provide the foundation for engineersto direct the drilling production.This paper combines theoretical research,, indoor variable parameters experiment withfield testing. The purpose of this paper is to obtain the influence law of lithology, weight onbit, rotary speed, and cutter diameter on the PDC bit drilling rate and improve the PDC bitdrilling rate equation and find the following results.1.According to the results of the theoretical research, we focused on analysis of lithology,weight on bit, rotary speed and cutter diameter, obtain the influence law on PDC bit drillingrate and the basic principles of using PDC bit.2. On the basis of the analysis of experimental results, the PDC bit drilling rate equation is modified,which uses the quadratic polynomial relationship instead of the power function relationship of drillingpressure and drilling rate, rotational speed and drilling rate in the drilling rate equation of4factors.3.We conduct the on-site verification in the medium-deep wells in Daqing Oil Field.Using the datafit software, each coefficient of the improved PDC bit drilling rate equation inthe area of ten layers is found, and then the drilling data of four Wells in the same region areselected. The average relative error between the actual average drilling rate and the predictedrate is from2.71%to10.47%, which indicates that the improved PDC bit drilling rate modelcan describe the drilling law well.