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

Well structures with ultra-long sections have become one of the most applied technologies in field shale gas development. While there been many technical challenges, enhancing breaking efficiency and stability polycrystalline diamond compact (PDC) bits has an essential issue focus. Since 2013, well structure Duvernay area optimized multiple times, rate penetration (ROP) entire wellbore nearly doubled. However, are significant differences terms performances different PDC bits, is still room for improvement to optimize these drill bits. For this reason, a confined compressive strength test was conducted obtain rock mechanical parameters from cores extracted long horizontal section. Using data, finite element model (FEM) developed corresponding scale. A calibration elastic-plastic damage constitutive models then performed using FEM. The mechanism three examined “PDC bit-bottom hole” interaction FEM model, facilitating guidance bit selection design optimization: (1) type B bit, which four blades 20 cutters, exhibited highest specific energy (MSE) lowest vibration across directional characteristics. This recommended engineering applications. (2) Lower axial vibrations were produced when CDE used as rear compared those BHE. increase within acceptable range observed TOB circumferential vibrations. Thus, redesigning work on assembly suggested. (3) decrease MSE characteristics depth cut (DOC) varied between 1.5 2.0 mm. broadening lateral forces noted DOC mm used. Therefore, redesign CDEs elements at recommended. In conclusion, new practical method optimization design, based mechanics theory, proposed.