Analysis of sucker rod and sinkerbar failures

Technical Report · Mon Mar 01 00:00:00 EST 1993

OSTI ID:6552800

Waggoner, J R; Buchheit, R G

This report presents results of a study of performance and failures of the sucker rod/sinkerbar string used in beam-pumping operations through metallography, finite element analysis, and failure data collection. Metallography showed that the microstructure of the steel bar stock needs to be considered to improve the fatigue resistance of the sucker rod strings. The current specification based on tensile strength, or yield strength, may not be appropriate since failure occurs because of fatigue and not yielding, and tensile strength is not always a good measure of fatigue resistance. Finite element analysis of the threaded connection quantitatively assesses the coupling designs under various loading conditions. Subcritical fractures in metallography are also suggested by calculated stress distribution in threaded coupling. Failure data illustrates both magnitude and frequency of failures, as well as categorizing the suspected cause of failure. Application of the results in each of these project areas is expected to yield improved choice of metal bar stock, thread design, and make-up practices which can significantly reduce the frequency of sucker rod failures. Sucker rod failures today are not inherent in the process, but can be minimized through the application of new technology and observation of common-sense practices.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6552800
• Report Number(s): SAND-92-1711; ON: DE93013600
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
OIL WELLS
ROD PUMPS
FAILURE MODE ANALYSIS
DATA ANALYSIS
FINITE ELEMENT METHOD
METALLOGRAPHY
MICROSTRUCTURE
PERFORMANCE
PUMPING
STRESS ANALYSIS
CALCULATION METHODS
CRYSTAL STRUCTURE
NUMERICAL SOLUTION
PUMPS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
WELLS
020300* - Petroleum- Drilling & Production