Drill String Elongation due to Tensile Load

Drill string elongation due to tensile load refers to the stretching or lengthening of a drill string when it is subjected to tension.  The drill string is a column of drill pipes and other tools used in drilling operations, particularly in oil and gas exploration.  When a tensile load is applied, typically due to the weight of the drill string itself and any additional forces from drilling operations, the drill string experiences elongation.

Drill string elongation must be carefully monitored and managed to ensure the efficiency and safety of drilling operations.  Excessive elongation can lead to operational challenges and potential failure of the drill string.  Drilling engineers must account for this elongation when designing the drill string and planning drilling operations.

 

Drill String Elongation due to Tensile Load formula
\( E \;=\;  DS_l \; T \;/\; 735000 \; DS_w    \)     (English) \( E \;=\;  DS_l \; T \;/\; 26.7 \; DS_w    \)     (Metric)
Symbol	English	Metric
\( E \) = elongation	\(in\)	\(mm\)
\( DS_l \) = drill string length	\(ft\)	\(m\)
\( T \) = tensile load	\(lbm\)	\(kg\)
\( DS_w \) = drill string weight	\(lbm \;/\; ft\)	\(kg \;/\; m\)