Downhole Measurement and Monitoring Lead to an Enhanced Understanding of Drilling Vibrations and Polycrystalline Diamond Compact Bit Damage

Abstract

Summary Since backward whirl was discovered as a severe cause of polycrystalline diamond compact (PDC) bit failure, the oil and gas industry has made great strides toward creating whirl-resistant bits and operating practices. But is whirl still the major cause of PDC bit damage in conventional rotary applications? This paper reports on a recent field study in which downhole vibrations were measured by use of a newly available in-bit vibration-monitoring device. The focus of this study was to understand the primary source of bit damage. In addition, four wells were also drilled by use of a research drilling rig in Oklahoma. In these tests, the PDC bits, bottomhole assemblies (BHAs), and operating parameters were varied to document their effect on downhole vibrations. In these four wells, vibration measurements from the new in-bit measuring device were validated against a commercially available and industry-proven measurement-while-drilling (MWD) vibration-monitoring service. The results of this study indicate that the most common field vibration in hard-rock vertical conventional rotary drilling is stick/slip, not whirl. In field tests, stick/slip was observed almost exclusively. For typical field applications with a surface rotary speed of approximately 70 rpm, the team measured a peak downhole rpm as high as 500 during the slip phase. Stick/slip was identified as the primary cause of bit damage in these applications. Lateral vibration occurring during the slip phase correlated well with the observed damage and is proposed as a new mode of damage during stick/slip. The characterization of the lateral vibrations coupled with stick/slip is presented on the basis of downhole measurements.

A Review of the Research and Development of High‐Frequency Measurement Technologies Used for Nonlinear Dynamics of Drillstring

“…For deeply understanding the intrinsic nature of the out-of-order behavior of this nonlinear systems, downhole measurements were started to support the drillstring dynamic research in the 1990s. After that, the research of drillstring dynamic stepped into the rapid development stage, and the vibrations and their correlation with formation characteristics, BHA whirl and bit bounce, resonance of the BHA, and vibration control and mitigation were researched based on downhole data [18][19][20][21][22][23], effectively promoted the BHA design and the production increasing.…”

A Review of the Evaluation, Control, and Application Technologies for Drill String Vibrations and Shocks in Oil and Gas Well

“…Sensor installation site has drill collar and bit. In the latest stage [11][12][13][14][15][50][51][52], the measuring instrument of dynamic drilling parameter (MIDDP) is combined with the rotary steerable system (RSS) and no drilling surprises (NDS) to solve practical problems. MIDDP has been successfully developed to improve the ability to control the drilling process and reduce drilling risks.…”

“…Several new methods and suggestions are investigated and discussed. According to the root mean square (RMS) and the experience threshold of measured acceleration value, evaluation criteria for drill string V&S was developed by Halliburton [7], Baker Hughes [8], APS [12], NOV, and Schlumberger [14,15] as shown in Tables 3 and 4. The applicable scope of practical measuring method to evaluate the drill string V&S levels is limited by the method accuracy, because of the fact that different oil fields have different stratigraphic characteristics.…”

“…Vibrations are unavoidable since drilling is the destructive process of cutting rock either by chipping or by crushing. Different drill string vibrations and shocks (V&S) occur in complex drilling environments [6][7][8][9][10][11][12][13][14][15][16], especially the poor drillability formation with extreme drill bit V&S, deep well and ultra-deep well with the long drill string, the deep water to ultra-deep water with vortex-induced vibration (VIV) of slender marine structures, coal and shale formation with borehole instability, irregular borehole diameter, and well trajectory increasing the level of drill string V&S. Drill string V&S cause serious failures of drilling tools and while-drilling-monitoring equipment such as drill pipe, drill collar [17,18], logging while drilling (LWD), measuring while drilling (MWD) [19], pressure and temperature while drilling (PTWD), engineering parameters while drilling (EPWD), pressure while drilling (PWD) [20][21][22], and drill bits [23]. Typical drilling tools failure due to the different drill string V&S are presented in Figure 1.…”

Whirl Interaction of a Drill Bit with the Bore-Hole Bottom

“…Chen et al [13] accentuated that in most cases bit whirl (backward or forward) is coupled with other forms of lateral vibrations, therefore, the trajectory of the bit center is usually not a circle. Wu et al [14] and Ledgerwood et al [15] [16] bind initiation of whirling vibrations with torsional stick/slip friction vibrations and consider it to be the primary cause of bit damage. Sowers et al [17] maintain this point of view and assert that additional detrimental effects caused by coupling of these phenomena include the development of ledges, bore-hole oscillations and spiraling, and premature failure of downhole tools.…”