Curing accelerant for proppant coating and methods of use
Environmentally acceptable branched alkyl alcohol ethoxylate accelerants for proppants coated with curable phenolic resin coating are described herein. Well treatment fluids described herein include an aqueous medium comprising a branched alkyl alcohol ethoxylate accelerant and a proppant having a curable phenolic resin coating dispersed in the aqueous medium.
1 . A method of treating a hydrocarbon reservoir, comprising:
conducting a hydraulic fracturing operation to fracture the hydrocarbon reservoir;
applying an accelerant-free proppant mixture to the fractured hydrocarbon reservoir, wherein the accelerant-free proppant mixture comprises a proppant having a curable phenolic resin coating;
applying an accelerated proppant mixture to the fractured hydrocarbon reservoir, wherein the accelerated proppant mixture comprises:
an aqueous medium comprising an accelerant, wherein the accelerant comprises a branched alkyl alcohol ethoxylate molecule; and
the proppant having the curable phenolic resin coating dispersed in the aqueous medium; and
adjusting a concentration of the accelerant in the accelerated proppant mixture applied to the fractured hydrocarbon reservoir in response to a stage of treatment and one or more downhole conditions, wherein adjusting the concentration of the accelerant comprises independently metering the accelerant to cause:
decreasing of the concentration in response to an increase in a temperature of the one or more downhole conditions; and
increasing of the concentration in response to a decrease in the temperature of the one or more downhole conditions.
2 . The method of claim 1 , wherein the branched alkyl alcohol ethoxylate molecule is PEG-5 propylheptyl ether.
3 . The method of claim 1 , wherein the branched alkyl alcohol ethoxylate molecule has the structure
wherein a, b, and c are integers that are each greater than or equal to 0, a≤y−3, b≤y−3, c≤y−3, wherein y is an integer greater than or equal to 6 and less than or equal to 36, y=a+b+c+3, and x is an integer of from about 1 to about 12.
4 . The method of claim 1 , wherein the branched alkyl alcohol ethoxylate molecule is a branched alkyl PEG5 or PEG3 ether.
5 . The method of claim 1 , wherein the branched alkyl alcohol ethoxylate molecule meets environmental regulations.
6 . A hydraulic fracturing method, comprising:
applying an accelerant-free proppant mixture to a hydrocarbon reservoir, wherein the accelerant-free proppant mixture comprises a first proppant having a first curable phenolic resin coating; and
applying an accelerated proppant mixture to the hydrocarbon reservoir, wherein applying the accelerated proppant mixture comprises:
pumping a proppant mixture into a wellbore, wherein the proppant mixture comprises an aqueous medium and a second proppant having a second curable phenolic resin coating; and
independently metering an accelerant into the proppant mixture to adjust a concentration of the accelerant in the accelerated proppant mixture, wherein the accelerant comprises a branched alkyl alcohol ethoxylate molecule configured to activate polymerization or curing of at least one of the first curable phenolic resin coating or the second curable phenolic resin coating, wherein independently metering comprises decreasing of the concentration in response to an increase in a temperature of the one or more downhole conditions, increasing of the concentration in response to a decrease in the temperature of the one or more downhole conditions, or both.
7 . The hydraulic fracturing method of claim 6 , wherein the branched alkyl alcohol ethoxylate molecule is PEG-5 propylheptyl ether.
8 . The hydraulic fracturing method of claim 6 , wherein the branched alkyl alcohol ethoxylate molecule has the structure
wherein a, b, and c are integers that are each greater than or equal to 0, a≤y−3, b≤y−3, c≤y−3, wherein y is an integer greater than or equal to 6 and less than or equal to 36, y=a+b+c+3, and x is an integer of from about 1 to about 12.
9 . The hydraulic fracturing method of claim 6 , wherein the branched alkyl alcohol ethoxylate molecule is a branched alkyl PEG5 or PEG3 ether.
10 . The hydraulic fracturing method of claim 6 , wherein the branched alkyl alcohol ethoxylate molecule has aquatic toxicity less than 1 ppm and sediment toxicity less than 10 ppm, biodegrades by more than 60% in 28 days, and is non-bioaccumulative.
11 . The hydraulic fracturing method of claim 6 , wherein the accelerated proppant mixture further comprises a material selected from the group consisting of an oxidative viscosity breaker, an encapsulated oxidative viscosity breaker, and an enzymatic viscosity breaker.
12 . The method of claim 1 , wherein at least one of the accelerant-free proppant mixture or the accelerated proppant mixture further comprises a material selected from the group consisting of an oxidative viscosity breaker, an encapsulated oxidative viscosity breaker, and an enzymatic viscosity breaker.
13 . The method of claim 1 , wherein the accelerant activates polymerization or curing of the curable phenolic resin coating.