Drill bit with effective side rake for weight on bit reducing effect

1 . A bit for drilling a wellbore, comprising:

a body; and

a crown comprising:

a cone section and a shoulder section;

of at least three blades protruding from the body, each blade extending from a center of the crown and across the shoulder section; and

a row of superhard cutters mounted along each blade, each cutter mounted in a pocket formed adjacent to a leading edge of the blade,

wherein:

each row has a plurality of inner cutters located in the cone section,

each inner cutter has an inclined face oriented to decline toward the center of the crown for creating an effective negative side rake angle while drilling with the drill bit and a weight on bit (WOB) reducing effect,

each of the rest of the cutters are oriented such that an overall effect for the bit is the WOB reducing effect,

each inclined face is a first inclined face,

each inner cutter has a central ridge and a second inclined face opposed to the first inclined face,

the inner cutters are arranged in a reverse spiral layout to concentrate a cutting area on the first inclined faces, and

the effective negative side rake angle is a net effective negative side rake angle.

2 . The bit of claim 1 , wherein each inner cutter is also oriented at a negative side rake angle.

3 . The bit of claim 2 , wherein an absolute value of the side rake angle ranges between 5 and 30 degrees.

4 . The bit of claim 1 , wherein:

each row has a plurality of outer cutters located in the shoulder section, and

each outer cutter has an inclined face oriented to decline away from the center of the crown for creating an effective positive side rake angle while drilling with the drill bit and a weight on bit (WOB) reducing effect.

5 . The bit of claim 4 , wherein:

each inclined face of the respective outer cutter is a first inclined face,

each outer cutter has a central ridge and a second inclined face opposed to the first inclined face,

the outer cutters are arranged in a forward spiral layout to concentrate a cutting area on the first inclined faces, and

the effective positive side rake angle is a net effective positive side rake angle.

6 . The bit of claim 4 , wherein each outer cutter is oriented at a positive side rake angle.

7 . The bit of claim 1 , wherein:

each row has a plurality of outer cutters located in the shoulder section,

each inner cutter is oriented at a side rake angle of about or less than zero, and

each outer cutter is oriented at a side rake angle of about or greater than zero.

8 . The bit of claim 1 , wherein each inner cutter is a shear cutter.

9 . The bit of claim 1 , wherein each cutter is fixed to the bit body such that each cutter does not rotate relative to the bit body while drilling with the drill bit.

10 . A bit for drilling a wellbore, comprising:

a body; and

a crown comprising:

a cone section and a shoulder section;

at least three blades protruding from the body, each blade extending from a center of the crown and across the shoulder section; and

a row of superhard cutters mounted along each blade, each cutter mounted in a pocket formed adjacent to a leading edge of the blade,

wherein:

each row has a plurality of outer cutters located in the shoulder section,

each outer cutter has an inclined face oriented to decline away from the center of the crown for creating an effective positive side rake angle while drilling with the drill bit and a weight on bit (WOB) reducing effect,

each of the rest of the cutters are oriented such that an overall effect for the bit is the WOB reducing effect,

each inclined face is a first inclined face,

each outer cutter has a central ridge and a second inclined face opposed to the first inclined face,

the outer cutters are arranged in a forward spiral layout to concentrate a cutting area on the first inclined faces, and

the effective positive side rake angle is a net effective positive side rake angle.

11 . The bit of claim 10 , wherein each outer cutter is also oriented at a positive side rake angle.

12 . The bit of claim 11 , wherein an absolute value of the side rake angle ranges between 5 and 30 degrees.

13 . The bit of claim 10 , wherein each cutter is fixed to the bit body such that each cutter does not rotate relative to the bit body while drilling with the drill bit.

14 . A bit for drilling a wellbore, comprising:

a body; and

a crown comprising:

a cone section and a shoulder section;

a plurality of blades protruding from the body, each blade extending from a center of the crown and across the shoulder section; and

a row of superhard cutters mounted along each blade, each cutter mounted in a pocket formed adjacent to a leading edge of the blade,

wherein:

each row has a plurality of inner cutters located in the cone section,

each inner cutter has an inclined face oriented to decline toward the center of the crown for creating an effective negative side rake angle while drilling with the drill bit and a weight on bit (WOB) reducing effect,

each of the rest of the cutters are oriented such that an overall effect for the bit is the WOB reducing effect, and

each inner cutter only has one inclined face in one direction extending across a cutting table thereof.

15 . The bit of claim 14 , wherein each inner cutter is also oriented at a negative side rake angle.

16 . The bit of claim 14 , wherein each cutter is fixed to the bit body such that each cutter does not rotate relative to the bit body while drilling with the drill bit.

17 . A bit for drilling a wellbore, comprising:

a body; and

a crown comprising:

a cone section and a shoulder section;

a plurality of blades protruding from the body, each blade extending from a center of the crown and across the shoulder section; and

a row of superhard cutters mounted along each blade, each cutter mounted in a pocket formed adjacent to a leading edge of the blade,

wherein:

each row has a plurality of outer cutters located in the shoulder section,

each outer cutter has an inclined face oriented to decline away from the center of the crown for creating an effective positive side rake angle while drilling with the drill bit and a weight on bit (WOB) reducing effect,

each of the rest of the cutters are oriented such that an overall effect for the bit is the WOB reducing effect, and

each outer cutter only has one inclined face in one direction extending across a cutting table thereof.

18 . The bit of claim 17 , wherein each inner cutter is also oriented at a negative side rake angle.

19 . The bit of claim 17 , wherein each cutter is fixed to the bit body such that each cutter does not rotate relative to the bit body while drilling with the drill bit.