Case Studies off the Bending Vibration and Whirling Motion off Drill Collars

Vandiver, Kim; Nicholson, J. W. G.; Shyu, Rong‐Juin

doi:10.2118/18652-pa

Cited by 80 publications

(24 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the drillstring rotates, a centrifugal force develops at the center of mass which causes it to bend and excites lateral vibrations called whirl (Vandiver et al 1990). Whirl is classified in two forms, forward and backward.…”

Section: Lateral Vibrationmentioning

confidence: 99%

Experimental Investigation of the Effects of Rotational Speed and Weight on Bit on Drillstring Vibrations, Torque and Rate of Penetration

Bavadiya

Alsaihati

Ahmed

et al. 2017

Day 3 Wed, November 15, 2017

View full text Add to dashboard Cite

Drillstring vibrations namely axial, lateral and torsional vibrations are the primary reason for downhole tool failure and reduction in rate of penetration (ROP). Factors like bit design, bottom hole assembly, bit-rock interaction, rotational speed, wellbore hydraulics, weight on bit (WOB) and drillstring-borehole interaction affect vibrations, out of which only rotational speed and WOB can be changed in real-time to minimize vibrations. It has been a topic of interest to understand and model downhole vibrations, minimize them and find an optimum range of drilling parameters to increase the drilling efficiency. This article presents the results of experimental studies conducted on a fully automated drilling rig to examine the effects of drilling parameters on drillstring vibrations, torque and rate of penetration. The study is different in terms of the high-speed range and the use of axial vibration transmitter to measure the vibration severity as per ISO standards. Experiments were performed on two different rock samples with varying strength. Perfect hole cleaning with negligible fluid flow effect was assumed. Each experiment was run for an average of six minutes collecting an average of 120 data points which were then averaged out for analysis. Parametric study was carried out to analyze the impacts of bit strength to rock strength ratio, bit constant and intrinsic specific energy on torque using existing model. As the drillstring was stiff and small, torsional oscillations were not observed and only lateral and axial vibrations were studied. Effect of drilling parameters and vibration on ROP was studied only on soft rock sample as ROP on hard rock was too small to be recorded Once the input parameters for the analytic model were methodically selected they show good agreement with the experimental data. The results of the parametric study revealed that estimation of torque relies heavily on the bit constant. Axial vibrations increased when rotational speed was near to the natural frequency of the drillstring which resulted in increase of ROP. Type of formation affected the magnitude of lateral and axial vibrations. Reducing both rotational speed and WOB helps to minimize lateral vibrations in hard formations while reducing rotational speed can effectively reduce axial vibrations.

show abstract

Section: Lateral Vibrationmentioning

confidence: 99%

Experimental Investigation of the Effects of Rotational Speed and Weight on Bit on Drillstring Vibrations, Torque and Rate of Penetration

Bavadiya

Alsaihati

Ahmed

et al. 2017

Day 3 Wed, November 15, 2017

View full text Add to dashboard Cite

show abstract

“…It can be shown by simple geometric calculations that backward whirl motion is asynchronous with drillstring rotation and that as the clearance between the rotor element (bit) and the borehole reduces toward zero, then the backward whirl frequency tends toward infinity (Vandiver et al 1990). However, tests show that as the borehole clearance tends towards zero, then backward whirl becomes increasingly less likely, ie; due to damping in fluid filled environments backward whirl can only occur in enlarged boreholes.…”

Section: Dangers Of Backward Whirlmentioning

confidence: 99%

Exploration of the Interaction Between Drill Bit Gauge Profile and Point-The-Bit Rotary Steerable Systems

2011

View full text Add to dashboard Cite

This paper describes an investigation of bit passive gauge profiles for a latest generation point-the-bit Rotary Steerable System (RSS) shown in Figure 1. Using theoretical analyses, a methodology has been developed for exploiting lateral stability afforded by extended passive gauge, without limiting steerability or creating stick-slip or high torque. Results of laboratory testing and field studies are presented, showing a step-change improvement in drilling performance and efficiency. Figure 1: Schematic diagram of a point-the-bit rotary steerable systemFull scale laboratory testing and field studies explore the impact of extended passive gauge in maintaining lateral stability. Results show that typically much longer passive gauge length than is common can be applied without adversely affecting steerability or stick-slip. These practical results are fully explained by theoretical analyses that predict critical gauge lengths. The optimum gauge profile is shown to be dependent on hole size and formation type.

show abstract

“…Different BHA whirl types have been identified with transverse bending-moment sensors and transverse magnetometers (Close et al 1988;Shyu 1989;Vandiver et al 1990;Macpherson et al 2001). Other researchers have used two sets of accelerometers in an RSS to detect and quantify collar/stabilizer whirl (Minett-Smith et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Continuous High-Frequency Measurements of the Drilling Process Provide New Insights Into Drilling-System Response and Transitions Between Vibration Modes

Bowler

Harmer

Logesparan

et al. 2016

SPE Drilling &Amp; Completion

View full text Add to dashboard Cite

The oil-and-gas industry has become increasingly interested in drilling dynamics and vibration as causes of drilling inefficiency and reduced drilling performance. Generally, drillstring vibration is measured with shock-and-vibration sensors installed in measurement-while-drilling (MWD) tools, logging-while-drilling (LWD) tools, and rotary steerable systems (RSS). Although these tools provide valuable real-time and recorded-mode information on the dynamic conditions, they are not generally designed to capture continuous high-frequency (HF) mechanics and dynamics data, and burst data may miss important information about the evolution of the system response and state.A downhole mechanics measurement tool has been developed that makes a comprehensive suite of measurements of the drilling process, including forces, accelerations, rotational speed, pressures, and temperatures. In addition to providing information in real time, the tool has the capability to capture long durations of continuous data at frequencies between 50 and 2,000 Hz. The recorded-mode information obtained has provided significant insight into the response of the drilling system to starting rotation; drilling procedures and parameter modifications; and exposure to excitation from sources including, but not limited to, rig heave, bottomhole-assembly (BHA) component imbalance, and bit/rock interaction. A wide range of occurrences has been captured in which the drilling system switches from a dominant vibration mode, typically torsional (downhole rotation-velocity oscillations or stick/slip) into a different mode, such as axial (bit bounce) or lateral (whirl). Transitions between different types of whirl have also been recorded.Several cases were studied to investigate the evolution and response of drilling-system behavior on the basis of in-depth interpretation of relatively long durations (minutes to hours) of HF data sets in the operational context. The findings verify the value of using continuous HF vibration data to understand the drilling system and to increase drilling performance.

show abstract

Case Studies off the Bending Vibration and Whirling Motion off Drill Collars

Cited by 80 publications

References 7 publications

Experimental Investigation of the Effects of Rotational Speed and Weight on Bit on Drillstring Vibrations, Torque and Rate of Penetration

Experimental Investigation of the Effects of Rotational Speed and Weight on Bit on Drillstring Vibrations, Torque and Rate of Penetration

Exploration of the Interaction Between Drill Bit Gauge Profile and Point-The-Bit Rotary Steerable Systems

Continuous High-Frequency Measurements of the Drilling Process Provide New Insights Into Drilling-System Response and Transitions Between Vibration Modes

Contact Info

Product

Resources

About