Hybrid Aqueous-Based Suspensions for Hydraulic Fracturing Operations
Disclosed are aqueous-based compositions and methods for treating a subterranean formation for inhibiting formation damage after the treatment. Compositions include an aqueous-based fluid, gelling agents, sparingly-soluble crosslinking agents, and one or more formation damage prevention agents, such as scale inhibitors, iron control agents, non-emulsifiers, clay stabilizers, or polymer breakers. The methods include performing a well treating operation, such as a hydraulic fracturing operation, using the compositions described and inhibiting formation damage, such as scale, iron formation, emulsions, or clay swelling within the subterranean formation. The inclusion of the formation damage preventing agents allows for long-term formation damage inhibition after the treatment.
1 . A well treatment fluid for the treatment of a well penetrating a subterranean formation, the fluid comprising:
an aqueous base fluid;
a gelling agent;
a sparingly-soluble crosslinking agent solution; and
a formation damage prevention agent.
2 . The well treatment fluid of claim 1 , wherein the base fluid is a brine.
3 . The well treatment fluid of claim 1 , wherein the formation damage preventing agent is an iron control agent.
4 . The well treatment fluid of claim 3 , wherein the iron control agent is a chelating agent or a sulfur-containing compound.
5 . The well treatment fluid of claim 1 , wherein the formation damage preventing agent is a scale inhibitor.
6 . The well treatment fluid of claim 5 , wherein the scale inhibitor is a phosphorus-containing compound, or an alkali metal or ammonium salt thereof.
7 . The well treatment fluid of claim 1 , further comprising one or more emulsifier inhibitors.
8 . The well treatment fluid of claim 7 , wherein the emulsifier inhibitor is selected from the group consisting of ethoxylated alkyl phenols, alkyl benzyl sulfonates, xylene sulfonates, alkyloxylated surfactants, ethoxylated alcohols, surfactants, phosphate esters, and oxyalkyl polyols.
9 . The well treatment fluid of claim 7 , wherein the emulsifier inhibitor includes a non-emulsifier enhancer.
10 . The well treatment fluid of claim 1 , further comprising one or more clay stabilizers.
11 . The well treatment fluid of claim 10 , wherein the clay stabilizer is selected from the group consisting of potassium chloride, sodium chloride, ammonium chloride, tetramethylammonium chloride, and combinations thereof.
12 . The well treatment fluid of claim 1 , further comprising one or more polymer breakers.
13 . A method of treating a subterranean formation, the method comprising:
providing a well treatment fluid during a well treatment operation that comprises an aqueous carrier fluid, a sparingly-soluble crosslinking agent, and one or more formation damage control agents;
injecting the well treatment fluid into a subterranean formation; and
retaining the well treatment fluid within the subterranean formation for a period sufficient to treat the well.
14 . The method of claim 13 , wherein the treatment operation is one of a fracturing operation, a water flooding operation, a drilling operation, a well bore workover operation, or a gravel packing operation.
15 . A process for treating a subterranean formation comprising steps of supplying via a well bore to a subterranean location, an aqueous oilfield fluid comprising an aqueous, viscosifying crosslinked reaction product of a polymer and a crosslinking agent, in combination with one or more formation damage control agents, and
exposing the fluid to conditions at the subterranean location which induce the formation damage control agent to the formation and thereby reduce damage to the formation during hydrocarbon recovery operations,
wherein the formation damage reduced or minimized is scale precipitation, iron formation, and/or “oil-water” emulsion formation.
16 . The process of claim 15 , wherein the aqueous fluid is used as one of a fracturing fluid, a drilling fluid, a diverting fluid or a gravel packing fluid.