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The ultimate technology for drilling oil wells by using pdc core bits

Polycrystalline diamond compact (PDC) core bits and pdc cutters have significantly contributed to the great improvements in the economies and efficiencies of gas and oil drilling for over the last 30 years. Since their introduction, many technological designs have been introduced and changed aiming at making them extremely effective tools for drilling in specific formations. pdc core bits constructed with pdc cutters that have been made from diamond, these cutters are designed to shear the rock and get deeper penetration, pdc core bits have numerous sintered-polycrystalline-diamond studs on the matrix, they drill quickly and have a long usability life. And pcd bits have proved successful in strength formations ranging from soft to moderate and homogeneous hard formations.

There are about ten studs on the matrix depending on the size of the pdc core bit. The bigger the bit, the higher the number of studs on it. To make a pdc core bit, synthetic diamond grits are formed with metal powders to be a substrate matrix on the top of the steel body. A wide range of pdc core bits of varying sizes are available and are fully customizable so as to meet the specific drilling requirements of the formation being drilled and the type of equipment that is being used.

pdc core bits have flushing holes or an open center and adjustable of fixed nozzles. Nozzles are needed because they provide turbulent jet flow through bits to keep the cutting areas clean. All varieties of pdc core bits are specifically designed to ensure optimal bit performance and longevity. Cuttings should not left behind in the core bit bcause they diminish the performance of the core bit. To assist in flushing the debris, junk slots or gauge reliefs are cut into the side of the body of the bit. Bit hydraulics are therefore very important in making sure all debris that are sheared away are flushed out.

Most homogeneous sedimentary rock formations like shale, dolomite, limestone and sandstone are easily worked on with pdc core bits. For harder abrasive formations such as dolomite and limestone, matrix body pdc core bits are commonly used because they provide excellently high levels of resistance to wear. Steel body pdc core bits are usually used when working on softer formations like sandstone. The core bits apply a shaving or shearing action when encountering the formation. The rotation speed of the core bits is significantly higher compared to other typical rotary bits. Hydraulics of pdc core bits have a design that keeps the hole clean and makes sure the core bit stay cool thus increasing the longevity.

pdc core bits have continued to improve the drilling performance in abrasive and hard formations ensuring durability by combining the following technologies that minimize cutter wear;
- Very superior hydraulic configurations
- Advanced cutting structure

The shape and structure of the pdc core bit can be described using the following terminology:
- Bit profile is the geometric surface that contacts formation. The types of the profiles include flat, cross, concave, convex, semi-round, stepped or parabolic.
- Cutter density is the number of pdc cutters on the matrix in a circle.
- The gauge protections applied to ensure longevity and also helps to maintain a straight hole.

Several factors determine the core bit is good or not, the aim of drilling is usually to make the hole with minimal time, to run core bits with a long working life so as to reduce trip time, and also to make sure the core bits drill a full size hole all through the drilling time. Choosing the best core bit for extraction of oil depends on factors among them the formation to be drilled, whether soft or hard.

It is always important to research about the specific core bits to be used and the manufacturers to supply the pdc core bits before setting out to buy them. This helps to make sure they are purchased from reputable and experienced manufacturers who have used the right technologies to make sure the core bits offer excellent performance and are of higher durability.