Research on Humble's high-speed low-torque equipment research project was originally handled by a research concern on a contract basis. Under this development contract three tools were built and considerable laboratory and field testing was done. Last year this tool was licensed to a bit manufacturer, and a development agreement was signed between them and Humble. Under these agreements two tools have been built which have been subjected to one laboratory test and seven field tests as of this date. A considerable history of mechanical failure has been developed, but as a result of the latest field tests it now appears almost certain that a commercial tool will evolve from this project.
In 1949, a research organization located in Texas, undertook an investigation sponsored by an organization formed to investigate new methods of drilling to determine the applicability of high-speed low-torque cutting elements to the drilling of wells. This work encompassed a survey of the literature and patent art and a rudimentary laboratory investigation of the ability of a wheel set with tungsten carbide cutters about its periphery to drill rock when rotated about its axis with a flexible shaft drive and with the entire unit rotated about an axis 900 to the wheel axis. Drilling rates up to about 20 ft/hour were obtained in lime while drilling a 4 -in. hole with the experimental device.
This work was dropped by the sponsoring organization since it was felt to be too closely related to conventional rotary drilling practice and, therefore, outside the scope of the organization purpose. Since Humble had patent rights on a turbine-driven drilling tool of the type making use of such a cutting technique, Humble assumed the sponsorship of the development program. Under this development agreement and extensions thereof laboratory and field development work was continued through the fall of 1955. In the summer of 1956 a bit manufacturing company undertook further development of this tool.
The original work conducted served merely as background since the work to be done for Humble was the development of a tool for field use. This required the design and building of a suitable surface test rig, determination of the most suitable materials for erosion resistance and cutting ability, and the development of operational techniques for use in the field. The tool was originally designed to drill 6 3/4-in. hole.