A New Theory on Cutter Layout for Improving PDC-Bit Performance in Hard-and Transit-Formation Drilling
- Shilin Chen (Halliburton) | Rob Arfele (Halliburton) | Seth Anderle (Halliburton) | Jorge Romero (Halliburton)
- Document ID
- Society of Petroleum Engineers
- SPE Drilling & Completion
- Publication Date
- December 2013
- Document Type
- Journal Paper
- 338 - 349
- 2013. Society of Petroleum Engineers
- 1.6 Drilling Operations, 1.5 Drill Bits, 1.6.9 Coring, Fishing
- 3 in the last 30 days
- 553 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
It is well-known that cutter layout on a polycrystalline-diamondcompact(PDC) bit plays a key role in bit stability and drilling efficiency. In today's PDC bit, cutters are laid out according to two general principles: single setor track set. A single-set cutter layout is defined as having no cutters at thesame radial or axial position after cutters are rotationally projected into aradial plane passing through the bit axis (this is referred to as bit profilein the industry). On the other hand, a track-set layout is defined as having atleast two cutters at the same radial and axial positions on a bit profile buton different blades. In most track-set designs, cutters on primary blades aresingle set, and cutters on minor blades are redundant to those on primaryblades. An extreme version of track set is called track loc, in which there isonly one primary blade and cutters on all other blades are redundant to thoseon the primary blade (Weaver and Clayton 1993). Figs. 1a through 1c depictsingle set, track set, and track loc, respectively, demonstrating that themajor difference is the engagement area or width of indentation of cutterswhile drilling. The single-set cutter has the smallest indentation width, andthe track-loc cutter has the largest indentation width. According to laboratoryand field tests, a PDC bit with single-set cutters drills much more efficientlythan a PDC bit with track-set cutters (Besson et al. 2000). On the other hand,a PDC bit with track-loc cutters is extremely stable but extremely inefficient.Bit stability may be enhanced by laying out the cutters so that the bit lateralforces are balanced or minimized. This is called a "force-balanced" PDC bit(Glowka 1989; Behr et al. 1993; Clayton et al. 2005). In some applications,cutters are laid out so that a large lateral imbalance force [as high as 15 to20% of weight on bit (WOB)] is created and directed toward a so-calledlow-friction gauge pad, which is on one side of the bit. The bit is called an"anti-whirl" PDC bit (Brett et al. 1989; Warren et al. 1990). Successful fieldapplications of this technology have been reported (Warren et al. 1990). Inthis paper, it is found that the force-balanced condition of a PDC bit withsingle-set cutters may be violated during transit-formation drilling. A newcutter layout procedure is proposed, which not only ensures the force-balancedcondition during transit drilling but also significantly improves drillingefficiency. The concepts developed in the paper are first verified bylaboratory tests of a core PDC head and then a full PDC bit. Two case studiesof the new bits in drilling through hard and transit formations are detailed inthe paper.
|File Size||1 MB||Number of Pages||12|
Behr, S.M., Warren, T.M., Sinor, L.A., et al. 1993. 3D PDC Bit ModelPredicts Higher Cutter Loads. SPE Drill & Compl 8 (4):253-258. http://dx.doi.org/10.2118/21928-PA.
Besson, A., Burr, B., Dillon, S., et al. 2000. On the Cutting Edge.Oilfield Rev. 12 (3): 36-57.
Brett, J.F., Warren, T.M. and Behr, S.M. 1989. Bit Whirl: A New Theory ofPDC Bit Failure. Paper SPE 19571 presented at the SPE Annual TechnicalConference and Exhibition, San Antonio, Texas, USA, 8-11 October. http://dx.doi.org/10.2118/19571-MS.
Clayton, R., Chen, S. and Lefort, G. 2005. New Bit Design, Cutter TechnologyExtend PDC Applications to Hard Rock Drilling. Paper SPE/IADC 91840 presentedat the SPE/IADC Drilling Conference, Amsterdam, Netherlands, 23-25 February. http://dx.doi.org/10.2118/91840-MS.
Glowka, D.A. 1989. Use of Single-Cutter Data in the Analysis of PDC BitDesigns: Part 1 - Development of a PDC Cutting Force Model. J. Pet Tech41 (8): 797-799, 844-849. http://dx.doi.org/10.2118/15619-PA.
Warren, T.M., Brett, J.F. and Sinor, L.A. 1990. Development of aWhirl-Resistant Bit. SPE Drill Eng 5 (4): 267-275. http://dx.doi.org/10.2118/19572-PA.
Weaver, G.E. and Clayton, R. 1993. A New PDC Cutting Structure Improves BitStabilization and Extends Application into Harder Rock Types. Paper SPE/IADC25734 presented at the SPE/IADC Drilling Conference, Amsterdam, Netherlands,22-25 February. http://dx.doi.org/10.2118/25734-MS.