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.