CARBOXYLATED CELLULOSE POLYMERS FOR USE IN HYDRAULIC FRACTURING OPERATIONS
A low residue fracturing fluid comprises water, an acidified carboxylated gelling agent in an amount in the range of from about 0.06% to about 0.48% by weight. The fracturing fluid can further include a stabilizer agent, a cross-linker, and a buffer.
1 . A low residue fracturing fluid comprising:
water;
an acidified carboxylated gelling agent in an amount in the range of from about 0.06% to about 0.48% by weight.
2 . The low residue fracturing fluid of claim 1 , wherein the acidified carboxylated gelling agent includes an acidity degree of at least 5%, such as at least 10%, at least 12%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, or at least 40%.
3 . The low residue fracturing fluid of claim 1 , wherein the acidified carboxylated gelling agent includes an acidity degree not greater than 99%, not greater than 95%, not greater than 90%, not greater than 85%, not greater than 80%, not greater than 75%, not greater than 70%, not greater than 65%, not greater than 60%, not greater than 55%, or not greater than 50%.
4 . The low residue fracturing fluid of claim 1 , wherein the acidified carboxylated gelling agent includes an acidity degree from 10% to 90%, from 40% to 90%, from 50% to 85%, or from 60% to 85%.
5 . The low residue fracturing fluid of claim 1 , wherein the carboxylated gelling agent is selected from the group consisting of a carboxylated galactomannan, a carboxylated glucomannan, a carboxylated cellulose, and a combination thereof.
6 . The low residue fracturing fluid of claim 1 , further comprising a non-carboxylated gelling agent.
7 . The low residue fracturing fluid of claim 6 , wherein the non-carboxylated gelling agent is selected from the group consisting of a galactomannan, a glucomannan, a cellulose, and a combination thereof.
8 . The low residue fracturing fluid of claim 6 , wherein a mass ratio of carboxylated gelling agent to a total of carboxylated gelling agent and non-carboxylated gelling agent ranges from 1 wt % to 99 wt %, from 10 wt % to 95 wt %, from 20 wt % to 90 wt %, from 30 wt % to 85 wt %, from 40 wt % to 80 wt %, or from 50 wt % to 75 wt %.
9 . The low residue fracturing fluid of claim 1 , wherein the carboxylated gelling agent is selected from carboxymethyl cellulose, carboxylated hydroxypropyl cellulose, carboxymethyl hydroxyethyl cellulose, carboxymethyl hydroxypropyl cellulose, carboxymethyl guar, carboxylated hydroxypropyl guar, carboxymethyl hydroxyethyl guar, carboxymethyl hydroxypropyl guar, carboxymethyl xanthan, carboxylated hydroxypropyl xanthan, carboxymethyl hydroxyethyl xanthan, carboxymethyl hydroxypropyl xanthan, or any combination thereof.
10 . The low residue fracturing fluid of claim 1 further comprising a cross-linking agent.
11 . The low residue fracturing fluid of claim 10 , wherein the cross-linking agent includes metal salt.
12 . The low residue fracturing fluid of claim 11 , wherein the metal is selected from boron, aluminum, zirconium, iron, antimony, titanium, or any combination thereof.
13 . The low residue fracturing fluid of claim 1 , wherein the fracturing fluid includes a chelating agent.
14 . The low residue fracturing fluid of claim 13 , wherein the chelating agent is selected from a diol, a diamine, a dicarboxylic acid, a carboxylic acid, an alkanol amine, a hydroxycarboxylic acid, an aminocarboxylic acid, or any combination thereof.
15 . The low residue fracturing fluid of claim 10 , wherein the cross-linking agent is present in an amount of at least 0.1 gpt, such as at least 0.15 gpt, at least 0.2 gpt, at least 0.25 gpt, at least 0.3 gpt, at least 0.4 gpt, or at least 0.5 gpt.
16 . The low residue fracturing fluid of claim 1 further comprising an oxygen scavenger.
17 . The low residue fracturing fluid of claim 1 , wherein the low residue fracturing fluid has a peak viscosity at 175 degF of at least 8000 cP per wt % amount of acidified carboxylated gelling agent.
18 . The low residue fracturing fluid of claim 1 , wherein the low residue fracturing fluid maintains a viscosity at 220 degF of at least 4000 cP per wt % amount of acidified carboxylated gelling agent for 45 minutes.
19 . A method of preparing a low residue fracturing fluid, the method comprising:
(a) hydrating a carboxylated gelling agent;
(b) adjusting the pH of the hydrated carboxylated gelling agent to less than 6 to form an acidified carboxylated gelling fluid; and
(c) mixing an oxygen scavenger, a cross-linking composition, a gel breaker, or any combination thereof with the acidified carboxylated gelling fluid.
20 . A method of treating a subterranean zone penetrated by a well bore comprising the steps of:
(a) preparing a viscous, low residue well treating fluid comprised of water, an acidified carboxylated gelling agent, a cross-linking composition, a oxygen scavenger, and a delayed gel breaker;
(b) pumping said well treating fluid into said zone by way of said well bore at a rate and pressure sufficient to treat said zone during which said hydrated gelling agent in said treating fluid is cross-linked by said retarded cross-linking composition; and
(c) allowing said viscous treating fluid to break into a thin fluid.