* Very coarse, permeable, and shallow, such as loose gravel
* Very coarse, permeable, and shallow, such as loose gravel
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* Naturally or intrinsically fractured
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* Naturally or intrinsically [[fracture]]d
* Easily fractured
* Easily fractured
−
* Underpressured or depleted
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* [[Underpressure causes|Underpressured]] or depleted
−
Lost circulation results in increased mud expense and may cause subsurface blowouts. The proper drilling fluids and use of lost circulation material will minimize lost circulation.
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Lost circulation results in increased mud expense and may cause subsurface [[Wikipedia:Blowout (well drilling)|blowouts]]. The proper drilling fluids and use of lost circulation material will minimize lost circulation.