It is common in oil and gas wells for the formation of pressure to be less than hydrostatic pressure (hydrostatic pressure is the bottom hole pressure required to hold a column of water from the perforations to the surface). For this type of well, a nitrified cleanout is required with conventional coiled tubing to achieve a cleanout. The primary advantage of the Sand Extraction Tool with dual coiled tubing is to perform a clean out in a sub-hydrostatic well without nitrogen.
A unique feature of the Sand Extraction Tool is the ability to generate a localized drawdown at every point of a highly deviated or horizontal wellbore (especially when the tool is in production mode). This is effective in removing localized drilling mud damage. This feature can also be used to evaluate production (oil, water and sand cuts) from various zones of the wellbore.
Benefits:
• Cleaning sub-hydrostatic pressure wells without nitrogen.
• Cleaning large and multi-ID completions by pumping liquid at a low pump rate.
• Pumping only water with friction reducer to conduct a cleanout (inexpensive).
• Cleaning wells with very low pressure gradients (i.e. 0.1 psi/ft or lower).
• Removing formation sand, proppants or drilling mud damage.
• Remove sand with the well in a balanced or slightly underbalanced condition
• Will not induce flow into the well or disturb the natural sand pack behind a slotted liner.
• The use of jetting mode to breakup a hard solids brigde or jet a stimulation fluid.
• Completely deliquify or remove the liquid column in a gas well with the tool in porduction mode.
• Conduct diagnostic analysis using the unique localized drawdown effect of the tool
• Diagnostic analysis is enhanced when running the Sand Extraction Tool with a memory pressure and temperature gauge.