VISCOUS FLUID SYSTEMS FROM WASTE WATER
By including a chemical additive in the well treatment fluid system design the cost and environmental impact of hydraulic fracturing may be substantially reduced. By adding a weak base to the well treatment fluid, water having a high, heterogeneous concentration of dissolved solids, such as water produced by oil and gas wells, may be utilized as the base fluid for hydraulic fracturing or other stimulation processes without adversely affecting the various components of the well treatment fluid. The well treatment fluid typically includes a base fluid, in this case produced water, a gelling agent, a weak base, and other additives useful for treating a well such as friction reducers, buffering agents, clay control agents, biocides, scale inhibitors, chelating agents, gel-breakers, oxygen scavengers, antifoamers, crosslinkers, wax inhibitors, corrosion inhibitors, de-emulsifiers, foaming agents, or tracers.
1 . A well treatment material comprising:
produced water, a viscosifying agent, a crosslinker, a buffering agent, and a weak base.
2 . The well treatment material of claim 1 wherein the viscosifying agent is present in an amount from about 8 pounds per thousand gallons of produced water to about 80 pounds per thousand gallons of produced water.
3 . The well treatment material of claim 1 wherein the viscosifying agent is present in an amount from about 15 pounds per thousand gallons of produced water to about 50 pounds per thousand gallons of produced water.
4 . The well treatment material of claim 1 wherein the viscosifying agent is present in an amount from about 20 pounds per thousand gallons of produced water to about 45 pounds per thousand gallons of produced water.
5 . The well treatment material of claim 1 wherein the crosslinker is present in an amount from about 0.05 gallons per thousand gallons of produced water to about 4.0 gallons per thousand gallons of produced water.
6 . The well treatment material of claim 1 wherein the crosslinker is present in an amount from about 0.1 gallons per thousand gallons of produced water to about 3.0 gallons per thousand gallons of produced water.
7 . The well treatment material of claim 1 wherein the crosslinker is present in an amount from about 0.2 gallons per thousand gallons of produced water to about 2.0 gallons per thousand gallons of produced water.
8 . The well treatment material of claim 1 wherein the weak base is present in an amount from about 0.1 pounds per thousand gallons of produced water to about 50.0 pounds per thousand gallons of produced water.
9 . The well treatment material of claim 1 wherein the weak base is present in an amount from about 5.0 pounds per thousand gallons of produced water to about 40.0 pounds per thousand gallons of produced water.
10 . The well treatment material of claim 1 wherein the viscosifying agent is a cellulosic polymer.
11 . The well treatment material of claim 1 wherein the viscosifying agent is a guar based polymer.
12 . The well treatment material of claim 1 wherein the viscosifying agent is a synthetic viscosifier.
13 . The well treatment material of claim 1 wherein the viscosifying agent is a sulfonated gelling agent.
14 . The well treatment material of claim 1 wherein the viscosifying agent is a sulfonated polysaccharide.
15 . The well treatment material of claim 1 wherein the weak base has a pKa of from about 7.01 to about 13.00.
16 . The well treatment material of claim 1 wherein the weak base has a pKa of from about 7.01 to about 10.50.
17 . The well treatment material of claim 1 wherein the weak base has a pKa of from about 7.01 to about 8.5
18 . A fracturing fluid comprising produced water, a viscosifying agent, at least one material useful for treating a wellbore, and a weak base.
19 . The fracturing fluid of claim 18 wherein at least one material useful for treating a wellbore is a friction reducer, a gelling agent, a clay control agent, a biocide, a scale inhibitor, a chelating agent, a gel-breaker, an oxygen scavenger, an antifoamer, a crosslinker, a wax inhibitor, a corrosion inhibitor, a de-emulsifier, a foaming agent, or a tracer.
20 . The fracturing fluid of claim 18 wherein the viscosifying agent is present in an amount from about 8 pounds per thousand gallons of produced water to about 80 pounds per thousand gallons of produced water.
21 . The fracturing fluid of claim 18 wherein the viscosifying agent is present in an amount from about 15 pounds per thousand gallons of produced water to about 50 pounds per thousand gallons of produced water.
22 . The fracturing fluid of claim 18 wherein the viscosifying agent is present in an amount from about 20 pounds per thousand gallons of produced water to about 45 pounds per thousand gallons of produced water.
23 . The fracturing fluid of claim 18 wherein the crosslinker is present in an amount from about 0.05 gallons per thousand gallons of produced water to about 4.0 gallons per thousand gallons of produced water.
24 . The fracturing fluid of claim 18 wherein the crosslinker is present in an amount from about 1.0 gallons per thousand gallons of produced water to about 3.0 gallons per thousand gallons of produced water.
25 . The fracturing fluid of claim 18 wherein the crosslinker is present in an amount from about 0.2 gallons per thousand gallons of produced water to about 2.0 gallons per thousand gallons of produced water.
26 . The fracturing fluid of claim 18 wherein the weak base is present in an amount from about 0.1 pounds per thousand gallons of produced water to about 50.0 pounds per thousand gallons of produced water.
27 . The fracturing fluid of claim 18 wherein the weak base is present in an amount from about 5.0 pounds per thousand gallons of produced water to about 40.0 pounds per thousand gallons of produced water.
28 . The fracturing fluid of claim 18 wherein the viscosifying agent is a cellulosic polymer.
29 . The fracturing fluid of claim 18 wherein the viscosifying agent is a guar based polymer.
30 . The fracturing fluid of claim 18 wherein the viscosifying agent is a synthetic viscosifier.
31 . The fracturing fluid of claim 18 wherein the viscosifying agent is a sulfonated gelling agent.
32 . The fracturing fluid of claim 18 wherein the viscosifying agent is a sulfonated polysaccharide.
33 . The fracturing fluid of claim 18 wherein the weak base has a pKa of from about 7.01 to about 13.00.
34 . The fracturing fluid of claim 18 wherein the weak base has a pKa of from about 7.01 to about 10.50.
35 . The fracturing fluid of claim 18 wherein the weak base has a pKa of from about 7.01 to about 8.5.