Abstract: A barite filter cake removing composition, and single- and multi-stage methods of removing a barite filter cake from a wellbore. The composition comprises at least one polymer removal agent, at least one chelating agent, and at least one converting agent. The single-stage method includes contacting the barite filter cake with the composition to dissolve the barite filter cake from the wellbore. The multi-stage method includes contacting the barite filter cake from the wellbore with at least one polymer removal agent to remove a polymer coat present on the barite filter cake, contacting the barite filter cake with at least one converting agent to convert barium sulfate in the barite filter cake to a barium salt of carbonate, formate, cyanide, nitrate, and/or chloride, and removing the barium salt of carbonate, formate, cyanide, nitrate, and/or chloride with at least one chelating agent.

Abstract: A barite filter cake removing composition, and single- and multi-stage methods of removing a barite filter cake from a wellbore. The composition comprises at least one polymer removal agent, at least one chelating agent, and at least one converting agent. The single-stage method includes contacting the barite filter cake with the composition to dissolve the barite filter cake from the wellbore. The multi-stage method includes contacting the barite filter cake from the wellbore with at least one polymer removal agent to remove a polymer coat present on the barite filter cake, contacting the barite filter cake with at least one converting agent to convert barium sulfate in the barite filter cake to a barium salt of carbonate, formate, cyanide, nitrate, and/or chloride, and removing the barium salt of carbonate, formate, cyanide, nitrate, and/or chloride with at least one chelating agent.

Abstract: A barite filter cake removing composition, and single- and multi-stage methods of removing a barite filter cake from a wellbore. The composition comprises at least one polymer removal agent, at least one chelating agent, and at least one converting agent. The single-stage method includes contacting the barite filter cake with the composition to dissolve the barite filter cake from the wellbore. The multi-stage method includes contacting the barite filter cake from the wellbore with at least one polymer removal agent to remove a polymer coat present on the barite filter cake, contacting the barite filter cake with at least one converting agent to convert barium sulfate in the barite filter cake to a barium salt of carbonate, formate, cyanide, nitrate, and/or chloride, and removing the barium salt of carbonate, formate, cyanide, nitrate, and/or chloride with at least one chelating agent.

Abstract: A drilling fluid system using retarded acid systems such as gelled acid (VES or polymer) and/or emulsified acid to drill carbonate formations (calcite and dolomite). Foamed acid may be used in low abnormal pressure carbonate reservoirs. The drilling fluid system permits drilling a target hydrocarbon-producing formation with zero-invasion of the drilling fluid system. A method for using the drilling fluid system for fluid loss control during drilling operations.

Abstract: A drilling fluid system using retarded acid systems such as gelled acid (VES or polymer) and/or emulsified acid to drill carbonate formations (calcite and dolomite). Foamed acid may be used in low abnormal pressure carbonate reservoirs. The drilling fluid system permits drilling a target hydrocarbon-producing formation with zero-invasion of the drilling fluid system. A method for using the drilling fluid system for fluid loss control during drilling operations.

Abstract: A barite filter cake removing composition, and single- and multi-stage methods of removing a barite filter cake from a wellbore. The composition comprises at least one polymer removal agent, at least one chelating agent, and at least one converting agent. The single-stage method includes contacting the barite filter cake with the composition to dissolve the barite filter cake from the wellbore. The multi-stage method includes contacting the barite filter cake from the wellbore with at least one polymer removal agent to remove a polymer coat present on the barite filter cake, contacting the barite filter cake with at least one converting agent to convert barium sulfate in the barite filter cake to a barium salt of carbonate, formate, cyanide, nitrate, and/or chloride, and removing the barium salt of carbonate, formate, cyanide, nitrate, and/or chloride with at least one chelating agent.

Abstract: A drilling fluid system using retarded acid systems such as gelled acid (VES or polymer) and/or emulsified acid to drill carbonate formations (calcite and dolomite). Foamed acid may be used in low abnormal pressure carbonate reservoirs. The drilling fluid system permits drilling a target hydrocarbon-producing formation with zero-invasion of the drilling fluid system. A method for using the drilling fluid system for fluid loss control during drilling operations.

Abstract: A drilling fluid system using retarded acid systems such as gelled acid (VES or polymer) and/or emulsified acid to drill carbonate formations (calcite and dolomite). Foamed acid may be used in low abnormal pressure carbonate reservoirs. The drilling fluid system permits drilling a target hydrocarbon-producing formation with zero-invasion of the drilling fluid system. A method for using the drilling fluid system for fluid loss control during drilling operations.

Abstract: A well clean-up fluid system than can be used to remove the filter cake in horizontal and multilateral sections of extended-reach and maximum-reservoir-contact wells for both open and cased hole completions. The fluid system contains one or more low pH chelating agents and a viscoelastic surfactant. The fluid is injected through a drill pipe and starts reacting with the filter cake after rigging down. This method of the well clean-up eliminates the use of coil tubing, enzymes and corrosion inhibitors. The efficiency of filter cake removal is enhanced because the well clean-up fluid system has the ability to divert through the highly damaged areas of well or formation in the horizontal section.