Method of servicing wellbores
AssigneeThe Dow Chemical Company
InventorsRandall C. Stauffer, Andrew J. Pasztor
Life of this patent
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Abstract
The servicing of wellbores with a high density fluid to maintain an elevated pressure on a portion of the formation penetrated by the well is improved. The improvement comprises injecting as the high density fluid a substantially solids-free aqueous solution of calcium bromide and zinc bromide having a density of at least about 15 pounds per gallon. The aqueous solution is prepared by reacting hydrogen bromide with zinc or compounds of zinc in the presence of an aqueous calcium bromide solution.
Claims21
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a crystallization point of less than about 50.degree. F., prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least about 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by reacting hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide.
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a crystallization point of less than about 50.degree. F. prepared by a process comprising:
- (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water;
- (b) adding an excess of hydrogen bromide;
- (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
A composition consisting essentially of a substantially solids-free aqueous solution of calcium bromide and zinc bromide, said solution having a density of at least 18 pounds per gallon and a weight ratio of calcium bromide to zinc bromide of from about 0.5:1 to about 0.2:1 prepared by a process comprising:
- (a) adding a zinc or zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water;
- (b) adding an excess of hydrogen bromide;
- (c) adding a sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6.
A composition prepared by a process comprising:
- reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form a solids free aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
A composition prepared by a process comprising:
- (a) adding a zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water;
- (b) adding an excess of hydrogen bromide;
- and
- (c) adding sufficient amounts of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
A process of preparing a high density well-servicing fluid comprising:
- reacting sufficient amounts of hydrogen bromide and zinc or a zinc compound in the presence of water and calcium bromide to form an aqueous solution of calcium bromide and zinc bromide having a density at least from about 18 pounds per gallon.
A process for preparing a high density well-servicing fluid comprising:
- (a) adding zinc or a zinc compound which will react with hydrogen bromide to form zinc bromide to a mixture of calcium bromide and water;
- (b) adding an excess of hydrogen bromide;
- and
- (c) adding sufficient amount of a base containing zinc or calcium cations to maintain a pH of from about 5 to about 6, to form an aqueous solution of calcium bromide and zinc bromide having a density of from about 18 pounds per gallon to about 20 pounds per gallon.
Dependencies are inferred from the claim text.