PDC bits with mixed cutter blades

Patent metadata

Field	Value
Publication number	US-10162911-B2
Application number	US-201514807396-A
Country	US
Kind code	B2
Filing date	Jul 23, 2015
Priority date	Dec 15, 2010
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Downhole drilling tools designed and manufactured to minimize or reduce imbalance forces and wear by disposing cutting elements in cutter groups and cutter sets in a level of force balance and by placing impact and/or wear resistant cutters on blades subject to high impact forces and/or large loadings. Manufacturing costs may be reduced by placing inexpensive cutters on blades not subject to high impact forces and/or loadings. Some embodiments comprise designing downhole tools with combinations of thicker blades to receive high impact forces and/or loadings with thinner blades. Some embodiments comprise designing downhole drilling tools with optimized fluid-flow properties. Designing methods may comprise performing simulations on a designed tool, evaluating respective forces acting on cutters during simulated engagement with a downhole (uniform and transitional) and/or evaluating wear on cutters and bit, and/or CFD simulations to evaluate fluid-flow optimization on a tool. Various cutter layout procedures and algorithms are described.

First claim

What is claimed is:

1. A method for designing a downhole drilling tool that is impact resistant comprising:
inputting into a computer a plurality of downhole drilling tool characteristics;
inputting into the computer a plurality of downhole drilling conditions;
simulating drilling a wellbore extending from a generally flat surface in a first downhole formation having a first compressive strength;
simulating drilling the wellbore with the downhole drilling tool into a second formation having a second compressive strength, wherein the second compressive strength is different from than the first compressive strength;
evaluating impact forces acting on each blade during drilling into the first downhole formation and during drilling into the second downhole formation;
evaluating loadings on each blade during drilling into the first formation and during drilling into the second formation;
evaluating volume of rock removed by each blade during drilling into the first formation and during drilling into the second formation;
determining a plurality of high impact blades;
determining a plurality of low impact blades;
installing a plurality of a first type of cutting element on the plurality of high impact blades, wherein the first type of cutting elements are selected from a group consisting of high impact resistant cutters, high wear resistant cutters, and combinations thereof; and
installing a plurality of a second type of cutting element on the plurality of low impact blades, wherein the second type of cutting element elements are selected from a group consisting of cutters that are low impact resistant cutters, cutters that are low wear resistant, and combinations thereof;
simulating drilling a wellbore into the first downhole formation and further into the second formation;
repeating evaluation of impact forces on each respective blade;
determining if conditions are met for reducing or minimizing impact on each respective blade;
modifying installing of one or more of the first type of cutting element on one or more respective blades and modifying installing of one or more of the second type of cutting element on respective blades if conditions are not met for reducing or minimizing impact on each respective blade; and
repeating simulations to determine if conditions are met for reducing or minimizing impact on each respective blade and repeating further modifying installing of at least one of the first type of cutting element and at least one of the second type of cutting element on respective each blade until conditions are met for a downhole tool that has minimized impact forces on each respective blade.

2. The method of claim 1 , further comprising evaluating wear on a blade or a part thereof following simulation of drilling into the first downhole formation and into the second downhole formation;
determining one or more respective blades subject to wear;
modifying installing of one or more of the first type of cutting element on one or more respective blades and modifying installing of one or more of the second type of cutting element on respective blades; and
repeating simulation of drilling and repeating evaluating wear and modifying installing of one or more of the first type of cutting element on one or more respective blades and modifying installing of one or more of the second type of cutting element on respective blades, until conditions are met for a downhole tool with optimized wear of the cutting elements.

3. The method of claim 1 , further comprising:
determining if the resulting forces acting on the downhole drilling tool are satisfactorily force balanced according to a criteria for multilevel force balancing during a first drilling simulation comprising engagement with the first downhole formation layer and a second drilling simulation during engagement with the second downhole formation layer comprising evaluating at least respective axial forces, respective lateral forces and respective bending moments on each cutter during simulated drilling into the first formation and the second formation;
modifying at least one location for installing respective cutting elements on exterior portions of the associated blades; and
repeating the first drilling simulation and the second drilling simulation and repeating the determining if the resulting forces acting on the downhole drilling tool are satisfactorily force balanced according to the criteria for multilevel force balancing, until the bit imbalance forces meet selected design requirements for multilevel force balance.

4. The method of claim 3 , wherein determining if the resulting forces acting on the downhole drilling tool are satisfactorily force balanced according to a criteria for multilevel force balancing during engagement with the first downhole formation layer and during engagement with the second downhole formation layer comprises:
determining locations for installing respective cutting elements on exterior portions of blades disposed on the downhole drilling tool;
simulating drilling a wellbore using the downhole drilling tool with each cutting element disposed at a respective first location on one of the blades and evaluating forces acting of each cutting element;
evaluating imbalance forces acting on the downhole drilling tool from each group of four neighbor cutting elements of the bit face profile; and
modifying the location for installing at least one of cutting elements based on the simulated imbalance force acting of the downhole drilling tool.

5. The method of claim 4 further comprising:
selecting a first optimum location for installing each cutting element on exterior portions of one of the blades based at least in part on balancing the forces acting on the cutting elements to minimize resulting imbalance forces acting on the downhole drilling tool;
projecting the blades and the associated cutting elements onto the bit face profile;
simulating forces acting on all cutting elements while drilling a wellbore with the first downhole formation layer and during engagement with the second downhole formation layer; and
evaluating imbalance forces acting on each group of three or four neighbor cutting elements on the bit face profile.

6. The method of claim 5 , wherein evaluating imbalance forces on each group of four neighbor cutting elements further comprises:
numbering the cutting elements on the composite cutting face profile starting with the cutting element closest to the bit rotational axis as number one and the last cutting element located the greatest distance from the bit rotational axis as number n;
evaluating imbalance forces acting on the first group of cutting elements numbered 1, 2, 3, and 4;
evaluating imbalance forces acting on the second group of cutting element numbered 2, 3, 4, and 5;
continuing to evaluate imbalance forces on the next consecutive group of cutting elements numbered 3, 4, 5, and 6; and
continuing to evaluate imbalance forces acting on the consecutive groups of cutting elements until the last group of cutting elements numbered n−3, n−2, n−1, and n has been evaluated.

7. The method of claim 5 , further comprising:
simulating forces acting on all cutting elements while drilling a wellbore; and
evaluating imbalance forces acting on each group of three neighbor cutting elements on the bit face profile.

8. The method of claim 7 , wherein evaluating imbalance forces on each group of three consecutive neighbor cutting elements further comprises:
numbering the cutting elements on the composite cutting face profile starting with the cutting element closest to the rotational axis as number one and the last cutting element on the bit face profile located the greatest distance as number n;
evaluating imbalance force

Assignees

• Chen Shilin
• Halliburton Energy Services Inc

Inventors

• Chen Shilin

Classifications

• E21B10/55 Primary

  with preformed cutting elements · CPC title

• E21B10/54

  the bit being of the rotary drag type, e.g. fork-type bits · CPC title

• E21B10/43

  characterised by the arrangement of teeth or other cutting elements · CPC title

• G06F17/5009 Primary

  Physics · mapped topic

• G06F17/5086

  Physics · mapped topic