Methods to control fluid loss in a well bore

摘要

The invention discloses a method of controlling fluid loss from a subterranean formation of a well bore. In a first aspect, the method is done by providing a treatment fluid made of an aqueous fluid and a hydrophobic polymer; and introducing the treatment fluid into the wellbore. In a second aspect, the method is done by providing a treatment fluid made of water and a water soluble polymer; providing in the treatment fluid a fluid loss additive having a hydrophobic polymer; using the treatment fluid in a well bore of a subterranean formation; allowing the treatment fluid to establish a permeable filter cake with the water soluble polymer in at least a portion of the well bore; and allowing hydrophobic polymer to enter into the filter cake to reduce permeability of the filter cake.