Numerical simulation study on the optimization design of the crown shape of PDC drill bit

Abstract

The design of bit crown is an important part of polycrystalline diamond compact (PDC) bit design, although predecessors have done a lot of researches on the design principles of PDC bit crown, the study of the law about rock-breaking energy consumption according to different bit crown shape is not very systematic, and the mathematical model of design is over-simplified. In order to analyze the relation between rock-breaking energy consumption and bit crown shape quantificationally, the paper puts forward an idea to take “per revolution-specific rock-breaking work” as objective function, and analyzes the relationship between rock properties, inner cone angle, outer cone arc radius, and per revolution-specific rock-breaking work by means of explicit dynamic finite element method. Results show that the change law between per revolution-specific rock-breaking work and the radius of gyration is similar for rocks with different properties, it is beneficial to decrease rock-breaking energy consumption by decreasing inner cone angle or outer cone arc radius. Of course, we should also consider hydraulic structure and processing technology in the optimization design of PDC bit crown.

Geometric Evolvement, Simulation, and Test of a Bionic Lateral PDC Reamer Bit Inspired by Capra sibirica Horn

“…In the simulation, as the hardness (10 with Mohs hardness scale) and strength (about 1500 MPa) of PDC teeth are much higher than those of the rock (3 with Mohs hardness scale and 60 MPa), the wear of PDC teeth in rock-breaking process is ignored. In order to improve calculation efficiency, like the other researches commonly did [ 28 , 29 ], the PDC teeth were regarded as rigid bodies and divided into a tetrahedral free mesh, the mesh size was 1 mm, and the parameters were set as those of common carbon steel and given in Table 2 . The type of the rock used in the simulation is limestone, which is widely distributed around the world.…”

Selection and Optimization Design of PDC Bits Based on FEM Analysis for Drilling Long Horizontal Sections of Shale Formations

“…The tangential mechanical response and breaking work based on the radial location of the bit profile were analyzed. The results indicate that the nasal area demonstrates the highest breaking work, while the internal cone angle profoundly influences the stress level across the entire radial profile [2]. Finite element modeling (FEM) offers a simpler and more feasible approach when compared to experimental methods, and semi-quantitative simulations can adequately represent the effects of various cutting structure features, even in the absence of experimental support [3].…”

Numerical modeling on drilling fluid and cutter design effect on drilling bit cutter thermal wear and breakdown

“…The previous studies on PDC drill bit crown and PDC drill bit cutter had proposed several design optimizations based on laboratory experiments (Curry et al 2015;Oliveira et al 2015;Stockey et al 2014;Azar et al 2013;Yahiaoui et al 2013) and finite element modeling (FEM) (Oliveira et al 2015;Rani et al 2015;Stockey et al 2014;Al-Muhailan et al 2013;Ju et al 2014;Freeman et al 2012). Oliveira et al (2015) proposed a new drill bit cutter design called dual-chamfer cutters for drilling in interbedded formations.…”

“…Stockey et al (2014) applied a uniform heat flux to both cutters, but they did not perform any modeling on the drilling fluid cooling effect on the drill bit cutter to reduce the thermal wear. Others (Oliveira et al 2015;Rani et al 2015;Al-Muhailan et al 2013;Ju et al 2014) also did not consider the drilling fluid cooling effect on drill bit cutter. Freeman et al (2012) performed experiments on the thermal mortality of the PDC planar cutter with two different drilling fluids which were water-and xanthan-based freshwater drilling fluid.…”