Use of potassium hydroxide solutions in a well bore
AssigneeMarathon Oil Company
InventorsRobert D. Sydansk, Frank S. Cordiner
Life of this patent
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Abstract
A workover fluid, a kill fluid, or completion fluid having potassium hydroxide dissolved therein is injected into a well bore penetrating and communicating with a subterranean sandstone formation containing water-sensitive fine particles, including clays, and invades the sandstone formation. Potassium hydroxide contacts and stabilizes the fine particles for a substantial period of time thereby substantially preventing formation permeability damage caused by encroachment of aqueous solutions having a distinct and undesired ionic constituency.
Claims40
In a process for working over a well bore penetrating and communicating with a water-sensitive, subterranean sandstone formation wherein a fluid is injected into and maintained within the well bore while a workover operation is performed, wherein the sandstone formation contains fine particles which interact with an aqueous solution having an ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, and wherein the injected fluid invades the sandstone formation and contacts at least a portion of the fine particles, the improvement comprising:
- incorporating potassium hydroxide into said injected fluid in an amount sufficient to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup for a substantial period of time, said potassium hydroxide existing in said injected fluid as potassium ions and hydroxide ions, said hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup.
In a process for killing a well bore penetrating and communicating with a water-sensitive, subterranean sandstone formation wherein an aqueous fluid is injected into and maintained within the well bore having a density sufficient to create a hydrostatic pressure greater than the formation pressure so as to prevent encroachment of fluids from the formation into the well bore, wherein the sandstone formation contains fine particles which interact with an aqueous solution having an ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, and wherein the injected fluid invades the sandstone formation and contacts at least a portion of the fine particles, the improvement comprising:
- incorporating potassium hydroxide into said injected fluid in an amount sufficient to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup for a substantial period of time, said potassium hydroxide existing in said injected fluid as potassium ions and hydroxide ions, said hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup.
In a process for completing a well bore penetrating and communicating with a water-sensitive, subterranean sandstone formation wherein a fluid is injected into the well bore in preparation for subsequent injection or production of fluids, wherein the sandstone formation contains fine particles which interact with an aqueous solution having an ionic makeup distinct from connate water to reduce permeability of the formation and fluid flow therethrough, and wherein the injected fluid invades the sandstone formation and contacts at least a portion of the fine particles, the improvement comprising:
- incorporating potassium hydroxide into said injected fluid in an amount sufficient to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup for a substantial period of time, said potassium hydroxide existing in said injected fluid as potassium ions and hydroxide ions, said hydroxide ions interacting with said sandstone formation in the presence of said potassium ions to effectively render said contacted fine particles relatively insensitive to said aqueous solution having a distinct ionic makeup.
Dependencies are inferred from the claim text.