US 4,722,402 A · Electromagnetic drilling apparatus and method

Abstract

Oil well drilling apparatus for drilling deep boreholes. The apparatus includes a high frequency, high voltage, AC generator at the surface of the ground which is connected to an electromagnetic hammer drill bit located at the bottom of the borehole. Electric current is conducted along a special drill string to the electromagnetic hammer drill located at the bottom of the hole. The drill string is a co-axial electrically conductive drill pipe which forms spaced annular current flow paths to the downhole electromagnetic hammer drill, while at the same time, drilling fluid flows along an axial flow path to the vibrating bit located at the bottom of the borehole. A special directional drill collar is positioned immediately above the electromagnetic hammer drill for controlling hole deviation. The co-axial electrically conductive lightweight drill pipe, the electrically conducting control deviation drill collars, and the electromagnetic hammer drill bit and pulse transformer each form a subcombination of the present invention; and, jointly comprise a new method and apparatus for forming boreholes.

Claims19

Dependent claims

Apparatus for forming a borehole comprising a drill string having an electric motor means and a drill bit connected at the lower end thereof, an axial passageway formed through said string and motor means through which drilling fluid can flow to a lower face of said bit;

means connecting said motor means to drive said bit;
said drill string includes inner and outer concentric electric conducting annular members, means by which said inner and outer annular members are electrically insulated from one another and form separate annular current flow paths from an upper end of the string to the motor means;
said drill string is made up of a multiplicity of series connected drill pipe joints, each of said joints having an upper male fluid and electrical conducting member and a lower female fluid and electrical conducting member;
the male and female members each having spaced annular conducting areas made complementary respective to one another to thereby provide said separtate annular current flow paths between adjacent joints;
whereby a source of electrical current can be connected at the upper end of the string and thereby provide the motor means with power.

2 more elements

In a borehole forming tool string of the type having an electric powered motor means at the lower end thereof by which a drill bit is actuated, and a drill pipe string having the lower end connected to support the motor means and the upper end connected to be supported by a derrick, the improvement comprising:

said pipe string comprises a plurality of pipe joints, each pipe joint has a connection at each opposed end thereof by which a plurality of joints can be connected into a pipe string;
each pipe joint comprises inner and outer annular electrical conductive members having insulation therebetween which electrically insulates the inner member from the outer member;
and a fluid passageway formed axially through the pipe joint;
said connection includes a threaded marginal end formed on the opposed ends of the inner and outer conductive members;
contact means at each connection at each opposed end of a pipe joint for electrically connecting adjacent outer members of adjacent pipe joints to one another and electrically connecting adjacent inner members of adjacent pipe joints to one another;
whereby a source of electrical current can be connected at the upper end of the string and thereby provide the motor means with power.

3 more elements

A fluid and electrical conductive pipe joint that can be connected into a pipe string by which drilling fluid can flow along a longitudinal axial flow path formed therein downhole to a drill bit, while an electrical current flow path can be established through the pipe string down to an electrical drill bit motor, and back up the string to the surface of the earth;

said pipe joint comprises an inner and an outer annular member concentrically arranged about a common axis and spaced radially to form an annular area therebetween, means by which the inner and outer members are electrically isolated from one another by insulation means located in the annulus formed therebetween;
fastener means formed at opposed ends of said pipe joint by which a plurality of pipe joints can be electrically and flow connected in series relationship to form a pipe string through which fluid and electricity can be conveyed;
said fastener means includes threaded opposed marginal ends of the inner and outer annular members;
whereby a source of electrical current can be connected at the upper end of the string and thereby provide a bit motor with power.

1 more element

Dependencies are inferred from the claim text.

Electromagnetic drilling apparatus and method

Life of this patent

Electromagnetic drilling apparatus and method

Life of this patent

Abstract

Claims19