Patent EA-001702-B1 (EA)
Title: Downhole motor assembly
Inventor: DOWNIE ANDREW
IPC: E21B7/06
Filed: 1999-01-20
Abstract: 1. A downhole motor assembly comprising a motor, at least one thrust bearing, and a bent portion, the assembly having a first end and a second end, the first end being closer to surface than the second end, in use, wherein the bent portion is closer to the second end than is the at least one thrust bearing, and, at least, one thrust bearing is provided between the motor housing and the assembly output shaft. 2. A downhole motor assembly as claimed in claim 1, wherein there is provided at least one further thrust bearing, being closer to the second end than is the bent portion. 3. A downhole motor assembly as claimed in any proceding claim, wherein the at least one thrust bearing is provided between the motor and the bent portion. 4. A downhole motor assembly as claimed in any preceding claim, wherein an at least one yet further thrust bearing is provided, wherein the at least one yet further thrust bearing is closer to the first end than is the motor. 5. A downhole motor assembly as claimed in claims 1 or 2 or claim 4 when dependent on claims 1 or 2, wherein the motor is provided between the at least one thrust bearing and the bent portion. 6. A downhole motor assembly as claimed in claim 5, wherein part of the motor is provided closer to the second end than is the bent portion. 7. A downhole motor assembly as claimed in any preceding claim, wherein the motor is provided within a motor drive section. 8. A downhole motor assembly as claimed in any preceding claim, wherein the at least one thrust bearing is provided within a thrust bearing section. 9. A downhole motor assembly as claimed in any preceding claim, wherein the bent portion comprises a bent housing. 10. A downhole motor assembly as claimed in any preceding claim, wherein the motor comprises one or more individual motors. 11. A downhole motor assembly as claimed in any of claims 1 to 10, wherein the motor is a hydraulic type. 12. A downhole motor assembly as claimed in any one of claims 1 to 10 wherein the motor is of a turbine type. 13. A downhole motor assembly as claimed in any of claims 1 to 10, wherein the motor comprises a Moineau motor, PDM motor, or an electric motor. 14. A downhole motor assembly as claimed in any of claims 1 to 13, wherein the at least one thrust bearing comprises at least one elastomer bearing and/or at least one metal bearing. 15. A downhole motor assembly as claimed in claim 14, wherein a plurality of elastomer and/or metal bearings are provided, the type and number being selected according to a required preselected thrust capacity. 16. A downhole motor assembly as claimed in claim 8 or any of claims 9 to 15 when dependent on claim 8, wherein the thrust bearing section includes a driveshaft. 17. A downhole motor assembly as claimed in claim 16, wherein the driveshaft is flexible. 18. A downhole motor assembly as claimed in claim 17, wherein the driveshaft is made at least partially from titanium or copper beryllium steel. 19. A downhole motor assembly as claimed in claim 9 or any of claims 10 to 18 when dependent upon claim 9, wherein the bent housing includes a driveshaft flexible coupling. 20. A downhole motor assembly as claimed in claim 16, wherein the second end includes an output shaft operably connected to the driveshaft. 21. A downhole motor assembly as claimed in any preceding claim, wherein the second end provides a bit connection means. 22. A downhole motor assembly as claimed in any preceding claim, wherein the motor assembly provides at least one stabiliser on an outermost surface thereof. 23. A downhole motor assembly as claimed in any preceding claim, wherein the motor assembly provides a first stabiliser at an end of the motor closer to the at least one thrust bearing than another end of the motor. 24. A downhole motor assembly as claimed in claim 23, wherein the motor assembly provides a second stabiliser at or near the second end of the assembly. 25. A downhole motor assembly as claimed in any preceding claim, wherein the motor and the at least one thrust bearing are coupled by a flexible coupling. 26. A downhole motor assembly as claimed in claim 10, wherein where the motor comprises a plurality of individual motors one or more individual motors are coupled one to the other by a further flexible coupling. 27. A method of directional drilling of a wellbore comprising providing a downhole motor assembly, the assembly comprising a motor, at least one thrust bearing and a bent portion, the assembly having a first end and a second end, the first end being closer to surface than the second end, in use, wherein the bent portion is closer to the second end than is the at least one thrust bearing and at least one one thrust bearing is provided between the motor housing and the assembly output shaft directionally drilling the well bore by means of the assembly.