The MRS™ STAR is a very unique tool, it comes complete with a 2.2 stage 7/8 lobe motor power section with mud-cooled sealed bearings that deliver over 6,000 ft-lbs of torque through carefully designed and chamfered stabilizer blade profile with gradual leading edges for both downward and upward reaming. The MRS™ STAR is fluid activated by circulating fluid down the drill string. Additional torque can be transferred to the tool by rotating the drill string.
The MRS™ STAR is based on the MRS™ concept and designed purely for drilling enhancement and for drilling applications only. It is specifically focuses on rigs with sufficient hydraulic power to but where torque limitations on either surface equipment or string components or both, limit string rotation to combat hole problems such as tight spots, swelling shales or wellbore collapse, where traditionally, the solution would have required backreaming. The MRS™ STAR includes a complete power section with rotor and stator (and the rotor could be lined with elastomer or may also come as rubberless). The rotor and stator are attached to the string in such a way as to cause the rotational force created to be applied only to the stator causing it to rotate.
The MRS™ STAR actuates with circulation. When fluid is circulated up to the threshold flow rate, the external sleeve starts to rotate clockwise looking downwards. This rotation is irrespective of the rotation of the drill string. The STAR is self torque-generating due to the associated power section that generates both torque and rotation. This family of tools will enable drilling teams to ream in and out of hole without string rotation making it the ultimate reaming solution for tight spots, hole pack-offs, swelling shales, and all manner of wellbore instability related issues.
Due to its unique internal power generation this tool will contribute lesser torque to the string in drilling mode that regular reamers or stabilisers.
- String rotation can be used to increase the available torque at the STAR for rock destruction and deformation.
- Due to its offset dynamics and harmonics it is expected to reduce stick slip or drill string vibrations.
- It is bored in the centre to ensure better signal transfer for telemetry systems that require to communicate using the internal fluid medium in the drill string.
- It will act as a conventional stabiliser as well as a reamer.