Enhance fluid recovery and improve cuttings dryness
Wintershall was drilling several onshore wells in the Neuquén
basin of Argentina using WBM. The drilling program began with water-base
bentonite spud mud for the upper sections, followed by KLA-SHIELD
enhanced-polymer water-base drilling fluid for the intermediate sections to TD.
The formations encountered during drilling were mainly coarse mineralized
sandstone and claystone layers in the first three intermediate sections;
limestone, silt, and calcareous formations in the fourth intermediate section;
and shales and bituminous marl in the production sections. The operator wanted
to increase the water-base drilling fluid recovery and cuttings dryness by
reducing the water-base drilling fluid volume on the drilled cuttings.
Reduce retention of cuttings in drilling fluid with SCREEN PULSE
separator
M-I SWACO recommended the SCREEN PULSE separator to Wintershall as the
optimal solution for meeting the operator’s goals. The operation called
for installing the SCREEN PULSE separator on three existing primary shakers
used for the intermediate and production sections. The operator aimed to
evaluate mud on cuttings under actual conditions using the SCREEN PULSE
separator with the primary shakers.
The SCREEN PULSE separator consists of a pulse control panel and carbon
fiber drop-in pans installed under the last screen on the discharge end of the
shakers to reduce fluid retention on the cuttings. This pneumatic system
applies compressed air to the pan assemblies, creating a vacuum that enhances
fluid recovery and cuttings dryness.
Increased fluid recovery and gained significant economic benefits
Samples were collected during steady-state conditions and when drilling
conditions were representative of daily operations. During the field trial,
process data as well as mud on cuttings, WBM lost volumes per shaker, final
disposal waste volumes, and other observations were recorded. In addition, an
analysis through laboratory field tests on the well was performed to compare
performance of the primary shakers when the SCREEN PULSE system was either on
or off.
The SCREEN PULSE separator performed continuously for 17 operating days
with 17 brief standby off periods. Evaluating the field trial results showed
the SCREEN PULSE separator helped achieve a final mud on cuttings average of
40% through the entire well. Drilled solids in the drilling fluid with the
SCREEN PULSE separator were reduced by approximately 28% through the shakers,
which enhanced fluid recovery and cuttings dryness. Savings on the final
disposal volume after adjustment was greater than 21%. With the SCREEN PULSE
separator, Wintershall saved an estimated USD 39,950.
