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Subterranean Well Bore Treatments with Urea Hydrochloride as a Breaker for Dissolving Filter Cakes and Mitigating Near Wellbore Damage Disclosure Number: IPCOM000209410D
Publication Date: 2011-Aug-03
Document File: 2 page(s) / 62K

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Urea hydrochloride has the potential of replacing almost any mineral acid during well bore treatment applications without the environmental hazards, VOCs, and corrosion dangers to metals posed by mineral acids. Urea hydrochloride is an effective method of removing of the built-up deposits of water-insoluble metals salts on surfaces and in the dissolution of water-insoluble metal salt dispersions or suspensions. Urea hydrochloride treatment is an effective method of dissolving calcium carbonate in well bores by application through limestone matrix stimulations, scale removal, and filter-cake-breaker clean-up systems.

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Subterranean Well Bore Treatments with Urea Hydrochloride as a Breaker for Dissolving Filter Cakes  and Mitigating Near Wellbore Damage 


Purpose of the Invention:   When drilling into the subterranean reservoir section of wells for the production of oil and gas, the 

reservoir‐drilling‐fluid produces a filter‐cake on the inside of the fluid‐producing zone, which is designed  for easier removal by breaker treatments of acid, oxidizer or enzyme materials. An acid breaker  treatment can constitute simply positioning an aqueous inorganic acid, such as hydrochloric acid, or an  aqueous organic acid, such as formic acid, in the production zone and keeping it in place in the  production zone for a period of time in order to react with the deposited filter cake components.  However, such highly reactive acids can result in incomplete filter cake removal, such as described by  the term worm‐holing.  

Delayed release, or slow release, acids and chelating‐agents can often be used to overcome the  previously described worm‐holing problem. A common type of delayed‐release acid system comprises  acid precursors that slowly hydrolyze to form acids that may ultimately degrade the acid‐soluble portion  of the filter cake.  


Description of the Invention:   Urea hydrochloride has the potential of replacing almost any mineral acid during well bore treatment 

applications without the environmental hazards, VOCs, and corrosion dangers to metals posed by  mineral acids. Urea hydrochloride is an effective method of removi...