Failure Analysis of Kelly Cock Valve Used in Drilling Process

2011 ◽  
Vol 71-78 ◽  
pp. 2610-2613 ◽  
Author(s):  
Xun Zheng ◽  
Jin Gen Deng ◽  
Hai Yan Zhu ◽  
Shu Jie Liu ◽  
Wen Long Zhao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Mechanical Analysis ◽  
Ball Valve ◽  
Main Body ◽  
Drilling Process ◽  
Element Calculation ◽  
Low Velocity ◽  
Low Velocity Zone ◽  
Theoretical Foundations ◽  
Velocity Zone

Though statistically analyzing ten typical wells of kelly cock valve failure in certain oilfields, the main failure modes of the kelly cock valve were determined. Aiming at these modes and combining with mechanical analysis of knob, upper seat and main body of the kelly cock valve, its finite element calculation had been implemented and the weakness of all parts was found. By numerical modeling of the flow field of a kelly cock valve it was found that the velocity of fluid rapidly increased at upper and lower valve seats and this could easily prick out ball valves and valve seats, there was a annular low-velocity zone of minimum speed between the ball valve and the inner wall of the main body and this caused solid aggregation at this area. The research in this paper made the modes and causes of kelly failure to be recognized systematically. The results provided theoretical foundations of further improving the design and reasonable using of a kelly cock valve.

Partial melting and the low-velocity zone

1970 ◽  
Vol 4 (1) ◽  
pp. 62-64 ◽  
Author(s):  
Don L. Anderson ◽  
Hartmut Spetzler
Keyword(s):  
Partial Melting ◽  
Low Velocity ◽  
Low Velocity Zone ◽  
Velocity Zone

Nature of the low velocity zone in Cascadia from receiver function waveform inversion

2012 ◽  
Vol 337-338 ◽  
pp. 25-38 ◽  
Author(s):  
Ralf T.J. Hansen ◽  
Michael G. Bostock ◽  
Nikolas I. Christensen
Keyword(s):  
Receiver Function ◽  
Waveform Inversion ◽  
Low Velocity ◽  
Low Velocity Zone ◽  
Velocity Zone

scholarly journals Fault Zone Guided Wave generation on the locked, late interseismic Alpine Fault, New Zealand

2021 ◽  
Author(s):  
JD Eccles ◽  
AK Gulley ◽  
PE Malin ◽  
CM Boese ◽  
John Townend ◽  
...  
Keyword(s):  
Fault Zone ◽  
Plate Boundary ◽  
Guided Wave ◽  
S Wave ◽  
Low Velocity ◽  
Catchment Scale ◽  
Near Surface ◽  
Low Velocity Zone ◽  
Alpine Fault ◽  
Velocity Zone

© 2015. American Geophysical Union. All Rights Reserved. Fault Zone Guided Waves (FZGWs) have been observed for the first time within New Zealand's transpressional continental plate boundary, the Alpine Fault, which is late in its typical seismic cycle. Ongoing study of these phases provides the opportunity to monitor interseismic conditions in the fault zone. Distinctive dispersive seismic codas (~7-35Hz) have been recorded on shallow borehole seismometers installed within 20m of the principal slip zone. Near the central Alpine Fault, known for low background seismicity, FZGW-generating microseismic events are located beyond the catchment-scale partitioning of the fault indicating lateral connectivity of the low-velocity zone immediately below the near-surface segmentation. Initial modeling of the low-velocity zone indicates a waveguide width of 60-200m with a 10-40% reduction in S wave velocity, similar to that inferred for the fault core of other mature plate boundary faults such as the San Andreas and North Anatolian Faults.

Topology of ray surfaces in low-velocity zones

1979 ◽  
Vol 69 (2) ◽  
pp. 369-378
Author(s):  
George A. McMechan
Keyword(s):  
Guided Waves ◽  
Turning Points ◽  
Three Dimensional ◽  
Focal Depth ◽  
Low Velocity ◽  
Low Velocity Zone ◽  
Ray Trajectories ◽  
Definition Of ◽  
Single Set ◽  
Velocity Zone

abstract Plotting of three-dimensional ray surfaces in p-Δ-z space provides a means of determining p-Δ curves for any focal depth. A region of increasing velocity with depth is represented in p-Δ-z space by a trough, and a region of decreasing velocity, by a crest. Two sets of ray trajectories, the arrivals refracted outside a low-velocity zone, and the guided waves inside the zone, can be merged into a single set along the ray that splits into two at the top of the low-velocity zone. This ray is common to both sets. This construction provides continuity of the locus of ray turning points through the low-velocity zone and thus allows definition of p-Δ curves inside as well as outside the low-velocity zone.

Peridotite-CO2-H2O and the low-velocity zone

1978 ◽  
Vol 41 (4) ◽  
pp. 670-683 ◽  
Author(s):  
P. J. Wyllie
Keyword(s):  
Low Velocity ◽  
Low Velocity Zone ◽  
Velocity Zone
Sign in / Sign up

Export Citation Format

Share Document