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AssigneeHalliburton Energy Services, Inc.
InventorsBradley L. Todd, B. Raghava Reddy, James V. Fisk, Jr., James D. Kercheville
Estimating the term…
Well drilling and servicing fluids for use in producing formations and methods of removing filter cake therefrom are provided. The methods basically comprise using a drilling or servicing fluid comprised of water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solid suspending agent and a particulate solid bridging agent which is soluble in an aqueous ammonium salt solution. Thereafter, the filter cake deposited by the drilling or servicing fluid is contacted with a clean-up solution comprised of water and an ammonium salt for a period of time such that the bridging agent is dissolved thereby.
In a well drilling or servicing fluid for use in producing formations and which deposits filter cake therein containing water, a density increasing water soluble salt, a fluid loss control agent, a hydratable polymer solids suspending agent and a particulate solid bridging agent, the improvement wherein said particulate solid bridging agent consists essentially of an inorganic compound which is dissolvable by a clean-up solution comprised of water and an ammonium salt, said inorganic compound selected from the group consisting of metal sulfates, metal tungstates, metal fluorides, metal phosphates, metal peroxides, metal fluosilicates, and metal oxides, said metal oxides being selected from the group consisting of magnesium oxide, calcium oxide, lanthanum oxide, cupric oxide and zinc oxide.
Dependencies are inferred from the claim text.