EFFECT OF PDC BIT DESIGN AND DRILLING FLUID ON RATE OF PENETRATION FOR MULTI-LAYER FORMATION

The project focuses on the optimization of Polycrystalline Diamond Compact (PDC)
drill bit design features for improvement in rate of penetration (ROP) for multi-layer
formation. Case history shows that conventional PDC drill bit failed to complete the
section that provides troublesome multi-layer formation. The PDC drill bit’s
performance dropped and affects the rate of penetration. Therefore, an intensive
study in PDC drill bit design features would help complete the section with high
ROP if the design features of PDC drill bit can be optimized. The enhancement of
ROP will result in the reduction of the well costs. Other than bit design, drilling fluid
also plays a vital role in the drilling process especially in sticky or soft formations.
Improper bottomhole cleaning was resulted from a poor drilling fluid circulation
which may results in accumulation of cuttings on the bit face that reduces the ROP.
The project started with getting the 3D CAD model of conventional PDC drill bits by
using reverse engineering approach. In this process, 3D scanner was used to scan the
dull PDC drill bit and converted the cloud model into a 3D CAD model. From there,
the design features of the model can be improved. Relatively deepened analysis was
carried out and come out with four important design parameters that can help in
improving the ROP. They are bit body material, size of cutter, shape of cutter and
row of cutter. The design of drilling simulation experiments are set up using Taguchi
method. Nine 3D models of PDC bit were selected and drawn in CATIA software.
Each 3D model was tested in simulation software to analyze the rate of penetration.
The drilling mud simulations were done using the same software to analyze the effect
of ROP on the properties of the drilling fluid.