STÜWA-CLEAN serves as mud-breaker for the removal of drilling fluid residues in the borehole.
It is a specially developed bentonite mud-breaker, which can be used for the construction of horizontal-/vertical spring wells and drainages.
By means of the horizontal and vertical fluid drilling process, filter screens are inserted into sand and gravel beds. In order to ensure the stability of the borehole in such formations, the use of drilling fluids containing bentonite is advisable. However, the problem is that the productivity of the well may be heavily decreased by the remaining bentonite residues.
This effect can be prevented if the mud-breaker STÜWA-CLEAN is used after application of the one-component drilling fluid STÜWAMIX®.
STÜWA-CLEAN acts as mud breaker by removing the electrostatic state of stress between the bentonite platelets. Thus the gel-forming “house of cards” structure of STÜWAMIX® is destroyed.
By insertion of a STÜWA-CLEAN solution of
- 5 % concentration for vertical wells
- 10 % concentration for horizontal wells
through a high-pressure jetting-system, the pore spaces of the natural grain fractions are flushed. In order to reach further areas of the aquifer behind the screen, the STÜWA-CLEAN water mixture, which is to be injected per borehole, should amount to:
- at least 10 % for vertical wells
- at least 25 % for horizontal wells
The reaction time is approx. 60 minutes for fresh drilling fluids. Afterwards, a rinsing process is to be effected by using the high-pressure jetting system so as to completely remove the residues of the drilling fluid as well as that of the mud-breaker. It is advisable to carry out this rinsing process section by section in-between packer units. It is imperative to carry out disinfection process prior to initial operation of the well.