A design method of conical tooth pdc bit

Abstract

The invention relates to a design method of a conical-tooth PDC drill bit, belongs to oil and gas well drilling tools and belongs to the field of the design study of the oil and gas well drilling tools. The method mainly comprises the following steps of obtaining the drillability of the rock through an indoor experiment and determining the well drilling condition according to the well drilling design requirement; then determining the number of drill bit blades and the diameters of cutting teeth according to the drillability of the rock; then determining the diameter of the drill bit accordingto the well drilling condition; and finally determining the height difference between a conical tooth and a PDC tooth according to the drillability of the rock and the drill bit structure parameter. According to the method, the drill bit structure parameter is designed in a mode that the experiment and the numerical calculation are combined, the calculation precision is high, the support is provided for the design of the conical-tooth PDC drill bit, and the rock breaking efficiency of the drill bit is improved.

Description

technical field [0001] The invention relates to a design method of a conical-toothed PDC drill bit, which belongs to the field of design science of oil and gas well drilling tools. [0002] technical background [0003] PDC bits rely on high-hardness, wear-resistant, self-sharpening polycrystalline diamond compacts (referred to as PDC teeth or cutting teeth) as cutting elements to shear and break rocks. PDC drill bits have high mechanical penetration rate, long service life and low drilling cost in soft to medium hard formations, so they are widely used in the drilling of oil and gas wells. [0004] In oil and gas drilling engineering, the geological conditions of the formation are often very complex. Under the pressure of the overlying formation and high-density drilling fluid, the mud shale and argillaceous sandstone in the deep formation not only increase in density and hardness, but also change from the normal pressure. Brittle rock transforms into plastic brittle rock o...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the design of the height difference between the conical tooth and the PDC tooth in the existing conical tooth PDC bit, which only relies on experience to design, a design method for the conical tooth PDC bit is proposed, which determines the drill bit by the drillability of the rock. The number of blades and the diameter of the cutting teeth, the diameter of the drill bit is determined by the drilling conditions, and finally the height difference between the conical teeth and the PDC teeth is determined by the rock drillability and the parameters of the drill bit. The present invention integrates experiments and numerical calculations. Design the structural parameters of the drill bit with high calculation accuracy, provide support for the design of the conical tooth PDC bit, and improve the rock breaking efficiency of the drill bit

Images