Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
Down-hole motor for directional drilling of boreholes in subsurface formations, said rotor including a housing suitable to be coupled to the lower end of a drill string, an output shaft suitable to be coupled to a drill bit, and a bearing unit that supports the output shaft in an inclined position relative to the housing, characterized in that the housing is provided with stabilizer means for centralizing the longitudinal axis I of the motor in a borehole and in that the bearing unit is mounted in such a manner in the housing that the central axis II of the output shaft intersects the longitudinal axis I at a point of intersection located outside the housing.
Claim 2
Dependent Claim
115 words
Down-hole motor for directional drilling of boreholes in subsurface formations, said rotor including a housing suitable to be coupled to the lower end of a drill string, an output shaft suitable to be coupled to a drill bit, and a bearing unit that supports the output shaft in an inclined position relative to the housing, characterized in that the housing is provided with stabilizer means for centralizing the longitudinal axis I of the motor in a borehole and in that the bearing unit is mounted in such a manner in the housing that the central axis II of the output shaft intersects the longitudinal axis I at a point of intersection located outside the housing.
Claim 3
Dependent Claim
33 words
The mofor as claimed in claim 1 having a drill bit connected thereto, wherein the point of intersection between the axes I and II is located near the face of the drill bit.
Claim 4
Dependent Claim
24 words
The motor as claimed in claim 1 or 2, wherein the angle of inclination between the axes I and II is less than 5°.
Claim 5
Dependent Claim
34 words
The motor as claimed in any one of claims 1-3, wherein the stabilizer means are formed by a series of stabilizers mounted on the motor housing at various locations along the longitudinal motor axis.
Claim 6
Dependent Claim
25 words
The motor as claimed in any one of claims 1-4, wherein the motor is provided with a hydraulically actuated rotor for driving the output shaft.
Claim 7
Dependent Claim
22 words
The motor as claimed in claim 5, wherein the output shaft is connected to the rotor by means of a universal joint.
Claim 8
Dependent Claim
14 words
The motor as claimed in claim 5, wherein the motor is a Moineau motor.
Claim 9
Dependent Claim
93 words
Method for directional drilling of a borehole with the down-hole motor according to claim 1 comprising the steps of (a) connecting a drill bit to the output shaft of the motor and connecting the motor housing to the lower end of a drill string and subsequently lowering the drill string, motor and bit in a borehole, (b) actuating the motor and applying weight on bit, and (c) simultaneously with step (b) rotating the drill string over periods that are preceded and succeeded by selected periods in which the drill string is not rotated.