Wellbore conditioning system
A wellbore conditioning system is disclosed. The system comprises at least one shaft and at least two eccentric unilateral reamers, wherein the unilateral reamers are positioned at a predetermined distance from each other and the unilateral reamers are positioned at a predetermined rotational angle from each other.
1. A wellbore conditioning system, comprising:
two coaxial shafts;
a screw joint coupling the two coaxial shafts; and
one unilateral reamer having only four cutting blades extending from each coaxial shaft, wherein the unilateral reamers are positioned at a predetermined distance from each other and, counter to the direction of rotation, the first blade extends a first distance from the drill string, the second blade extends a second distance from the drill string greater than the first distance, the third blade extends a third distance from the drill string greater than the second distance, and the fourth blade extends a fourth distance from the drill string greater than the third distance;
wherein the unilateral reamers are diametrically opposed to each other and do not overlap.
2. The wellbore conditioning system of claim 1 , wherein each unilateral reamer extends from an outer surface of the at least one shaft in a direction perpendicular to the axis of rotation of the two coaxial shafts.
3. The wellbore conditioning system of claim 1 , further comprising a plurality of cutters coupled to each blade.
4. The wellbore conditioning system of claim 3 , wherein each cutter is a Polycrystalline Diamond Compact (PDC) cutter.
5. The wellbore conditioning system of claim 1 , further comprising at least one dome slider coupled to each blade.
6. The wellbore conditioning system of claim 5 , wherein each dome slider is a PDC dome slider.
7. The wellbore conditioning system of claim 1 , further comprising a recess in each shaft adjacent to each reamer.
8. A wellbore drilling string, comprising:
a drill bit;
a downhole mud motor;
a measurement-while-drilling (MWD) device relaying the position of the drill bit and the downhole mud motor to a controller; and
a wellbore conditioning system, wherein the wellbore conditioning system comprises:
two coaxial shafts;
a screw joint coupling the two coaxial shafts; and
one unilateral reamer having only four cutting blades extending from each coaxial shaft, wherein the unilateral reamers are positioned at a predetermined distance from each other and counter to the direction of rotation, the first blade extends a first distance from the drill string, the second blade extends a second distance from the drill string greater than the first distance, the third blade extends a third distance from the drill string greater than the second distance, and the fourth blade extends a fourth distance from the drill string greater than the third distance;
wherein the unilateral reamers are diametrically opposed to each other and do not overlap; and
wherein the wellbore conditioning system is positionable within the wellbore drill string at a location in or around the bottom hole assembly.
9. The wellbore drilling string of claim 8 , wherein each unilateral reamer extends from an outer surface of the at least one shaft in a direction perpendicular to the axis of rotation of the two coaxial shafts.
10. The wellbore drilling string of claim 8 , further comprising a plurality of cutters coupled to each blade.
11. The wellbore drilling string of claim 10 , wherein each cutter is a Polycrystalline Diamond Compact (PDC) cutter.
12. The wellbore drilling string of claim 8 , further comprising at least one dome slider coupled to each blade.
13. The wellbore drilling string of claim 12 , wherein each dome slider is a PDC dome slider.
14. The wellbore drilling string of claim 8 , further comprising a recess in each shaft adjacent to each reamer.
15. A wellbore conditioning system, comprising:
two coaxial shafts;
a screw joint coupling the two coaxial shafts; and
one unilateral reamer having four cutting blades extending from each coaxial shaft, wherein the unilateral reamers are positioned at a predetermined distance from each other and, counter to the direction of rotation, the first blade extends a first distance from the drill string, the second blade extends a second distance from the drill string greater than the first distance, the third blade extends a third distance from the drill string greater than the second distance, and the fourth blade extends a fourth distance from the drill string greater than the third distance, wherein none of the blades extends the same distance as any other blade;
wherein the unilateral reamers are diametrically opposed to each other and do not overlap.
16. A wellbore drilling string, comprising:
a drill bit;
a downhole mud motor;
a measurement-while-drilling (MWD) device relaying the position of the drill bit and the downhole mud motor to a controller; and
a wellbore conditioning system, wherein the wellbore conditioning system comprises:
two coaxial shafts;
a screw joint coupling the two coaxial shafts; and
one unilateral reamer having four cutting blades extending from each coaxial shaft, wherein the unilateral reamers are positioned at a predetermined distance from each other and counter to the direction of rotation, the first blade extends a first distance from the drill string, the second blade extends a second distance from the drill string greater than the first distance, the third blade extends a third distance from the drill string greater than the second distance, and the fourth blade extends a fourth distance from the drill string greater than the third distance, wherein none of the blades extends the same distance as any other blade;
wherein the unilateral reamers are diametrically opposed to each other and do not overlap; and
wherein the wellbore conditioning system is positionable within the wellbore drill string at a location in or around the bottom hole assembly.