Controlled dewatering of confined, saturated formations in excavation mines

摘要

Methods to control dewatering of confined, saturated formations in excavation mines may include treating a portion of an untreated smectite shale barrier with a dewatering fluid thereby yielding a treated smectite shale barrier, wherein the untreated smectite shale barrier is associated with a confined, saturated formation that comprises water, and wherein the dewatering fluid comprises an aqueous base fluid and a dewatering additive; and draining at least a portion of the water from the confined, saturated formation through the treated smectite shale barrier. In some instances, the dewatering additive may include potassium citrate and potassium nitrate each independently in a concentration of about 0.5% to about 5% by weight of the aqueous base fluid.

主权项

1. A method comprising:
providing an untreated smectite shale barrier confining a saturated formation that comprises water; accessing the untreated smectite shale barrier adjacent to an excavation mine; drilling a borehole into the untreated smectite shale barrier from the excavation mine with a dewatering fluid without breaching the untreated smectite shale barrier into the saturated formation, wherein a portion of the untreated smectite shale barrier contacted by the dewatering fluid becomes a treated smectite shale barrier that has a greater water permeability than the untreated smectite shale barrier, wherein the dewatering fluid comprises an aqueous base fluid and a dewatering additive; and draining at least a portion of the water from the confined, saturated formation through the treated smectite shale barrier.