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Unformatted text preview: use of the lost circulation material “pills” as spacer. 207 On April 20, the rig crew blended the spacer from the lost circulation materials to a 16.0 ppg density. The rig crew pumped 454 barrels of spacer into the well, more than twice as much material as is typically used. The Panel found no evidence that BP considered the possibility that pumping a large amount of 16.0 ppg lost circulation material into the well might risk clogging the choke line or the kill line. Nor did the Panel find evidence that BP discussed this possibility with the rig crew. A clogged choke line or kill line would lead to pressure differentials with the drill pipe and would complicate any negative test procedures using either line. In its post‐blowout investigation, BP concluded that the presence of this spacer allowed for viscous material to be present across the choke and kill lines during the negative test and that this possibly plugged the kill line. 208 This is a possible explanation for the pressure differential between the drill pipe and kill line. D.
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