Decrease production time lost because of poor screen performance

An operator was boring 5,300 ft [1,615 m] for a pipeline project in New York City and used conventional screens on its Derrick FLC 500 Series shakers to divert fluid to the tank during a 32-in [81.3-cm] ream pass. However, efficiency was compromised by the OEM screens' inadequate solids conveyance and poor fluid-handling capacity at the flowline shaker. The screens' wire cloth restricted fluid conductance, causing a thick bed of cuttings to accumulate in the valleys of the corrugated screens.

At 500-ft [152-m] MD, the operator found it necessary to slow reaming to allow the screen to catch up to the pump rate. Over 2 days, the repeated process of slowing reaming to compensate for the mud system resulted 20 minutes’ lost production per 32-ft [9.8-m] pipe joint.

Test DURAFLO D500-C replacement screen against conventional setup

M-I SWACO recommended conducting a side-by-side test to compare the fluid-handling capacity of the DURAFLO D500-C replacement screen with the performance of the OEM screen. The rig was equipped with two simultaneously operating Derrick FLC 500 Series shakers for comparison under equivalent conditions.

Testing began at approximately 2,000-ft [610-m] MD on the 32- and 42-in [106.7-cm] ream passes. The same shaker deck angles and flow rates of 550 galUS/min [1.89 m3/s] were maintained for the duration of the comparison to ensure equivalent operating conditions.

Replace all OEM screens with DURAFLO D500-C screens

During testing, the corrugated screens could not accommodate the pump output, so their flowline valves were adjusted to 20% open. The DURAFLO D500-C screen valves were adjusted to 50% open. Because the screens were choked back, the mud flow was pushing more volume and pressure to the DURAFLO D500-C screen. The solids conveyance capabilities of the DURAFLO D500-C screens enabled processing at maximum flow capacity. The screens also managed smaller particles compared with the conventional screens.

When the project superintendent saw that the DURAFLO D500-C screen surpassed the fluid-handling capacity of the corrugated screen, it was decided to replace all of the corrugated screens with DURAFLO D500-C screens. Once the screens were replaced, the operator opened both valves to 100%. The DURAFLO D500-C screens handled the entire volume that the pit pump transferred to the shakers while maintaining an ROP of 120 ft/h. There was no additional time lost due to limited shaker handling capacity.