Drillstring Elongation due to Tensile Load

Drillstring elongation due to tensile load refers to the stretching or lengthening of a drillstring when it is subjected to tension.  The drillstring 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.

Drillstring 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 drillstring.  Drilling engineers must account for this elongation when designing the drillstring and planning drilling operations.   

 

Drillstring Elongation due to Tensile Load Formula
\( E \;=\; \dfrac{ DS_l \cdot T }{ 735000 \cdot DS_w  }  \)     (English) \( E \;=\;  \dfrac{ DS_l \cdot T }{ 26.7 \cdot DS_w  }  \)     (Metric)
Symbol	English	Metric
\( E \) = elongation	\(in\)	\(mm\)
\( DS_l \) = drillstring length	\(ft\)	\(m\)
\( T \) = tensile load	\(lbm\)	\(kg\)
\( DS_w \) = drillstring weight	\(lbm \;/\; ft\)	\(kg \;/\; m\)