Abstract: A flexible steering sub is disclosed for flexible drilling of horizontal oil and gas wells, horizontal storage wells, geothermal drilling for electric power generation; earth sciences study of and monitoring of earth movement with respect to fault movement; environmental science cleaning up of inaccessible polluted areas; coring to test rock strength prior to large scale constructions such as dams; introduction of chemicals for solution mining logging while drilling short radius well bores, and the like. The flexible sub comprises an elongated housing having a plurality of housing sections connectable at one end to an orientation sub for a PDM drill and connectable at the other end to a wire line connector. An electronics assembly including guidance directional guided sensors, directional probe and logging while drilling probe is positioned in a plurality of the housing sections, interconnected electrically, and connected at one end to the wire line connector.

Abstract: A system of apparatus for arcuate drilling into the earth is disclosed which comprises a drill string extending into a well bore in the earth and a fluid operated drill motor and drill bit operated thereby secured on the bottom end of the drill string. The drill motor is connected at its upper end to the drill string and at its lower end to the drill bit for rotating the drill bit independently of rotation of the drill string. The drill motor has a tubular drive section housing constructed of non-magnetic material, preferably a Beta-C titanium alloy containing titanium, aluminum, vanadium, chromium, zirconium and molybdenum in the proportions Ti-3Al-8V-6Cr-4Zr-4Mo. The longitudinal axis of the drill motor housing has its upper and lower ends angularly displaced from the longitudinal axis of its central portion end for directing the axis of rotation of the drill bit such that it is angularly displaced from the axis of the drill string for effecting a curved path for the wellbore.

Abstract: A flexible steering sub is disclosed for flexible drilling of horizontal wells, geothermal drilling for electric power generation; earth sciences study of and monitoring of earth movement with respect to fault movement; environmental science cleaning up of inaccessible polluted areas; coring to test rock strength prior to large scale constructions such as dams; introduction of chemicals for solution mining, and the like. The flexible sub comprises an elongated housing having a plurality of housing sections connectable at one end to an orientation sub for a PDM drill and connectable at the other end to a wire line connector. An electronics assembly including guidance directional sensors and probe is positioned in a plurality of the housing sections, interconnected electrically, and connected at one end to the wire line connector.