During the drilling procedure, the mud filtrates continuously penetrate into the formation because of the unbalance between the mud column pressure in the borehole and formation pressure.

在钻井过程中，井筒泥浆柱压力和地层压力的不平衡使得泥浆滤液不断渗入地层。

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If a stable column of mud has been set up in the well, keeping the oil at bay through its sheer weight, the next step would be to set cement in the well and seal it off permanently.

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