Welltest 103: Acoustic Well Sounder Surveys
The most common method of creating an #AWS sound wave is to charge a gas gun chamber with compressed N2 or CO2. When this is released instantaneously into the wellbore an explosion impulse is created. An alternative method, in high pressure sweet gas (#LNG), is to allow well gas to instantaneously fill the empty chamber, causing an implosion impulse.
The difference between explosion or implosion is critical to interpretation of #welltest strip chart kicks (either paper or digital). It is easily determined by the very first kick on the strip chart…
Explosion shot’s first kick is downward. Obstructions (collars, anchors, liquid level) also kick downward. Expansions (perforation holes, end-of-tubing) kick upward.
Implosion shot’s first kick is upward. Obstructions (collars, anchors, liquid level) also kick upward. Expansions (perforation holes, end-of-tubing) kick downward.
