Drillstring Stretch

on 21 December 2024. Posted in Drilling Engineering

Drillstring stretch is the elongation of the drillstring under tension when it is subjected to axial forces during drilling operations.

Drillstring Stretch Formula
\( \Delta L \;=\; \dfrac{ F \cdot L \cdot 12 }{ \lambda \cdot A_c } \) (Drillstring Stretch) \( F \;=\; \dfrac{ \Delta L \cdot \lambda \cdot A_c }{ L \cdot 12 } \) \( L \;=\; \dfrac{ \Delta L \cdot \lambda \cdot A_c }{ F \cdot 12 } \) \( \lambda \;=\; \dfrac{ F \cdot L \cdot 12 }{ \Delta L \cdot A_c } \) \( A_c \;=\; \dfrac{ F \cdot L \cdot 12 }{ \Delta L \cdot \lambda } \)
Symbol	English	Metric
\( \Delta L \) = Stretch Length	\(in\)	-
\( F \) = Pull Force	\(lbf\)	-
\( L \) = Pipe Length	\(ft\)	-
\( \lambda \) (Greek symbol lambda) = Elastic Modulus (psi)	\( lbf \;/\; in^2 \)	-
\( A_c \) = Area Cross-section	\( in^2 \)	-

Piping Designer Logo Slide 1