# US 2013/0157904 A1 · Green coal bed methane fracturing fluid compositions, methods of preparation and methods of use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157904 A1 - Document ID: US20130157904A1 - Status: Published application - Kind: A1 - Application number: 13/768,188 - Filed: 2013-02-15 - Published: 2013-06-20 - Earliest claimed: 2008-07-25 - Assignees: Calfrac Well Services Ltd. - Inventors: Timothy Tyler Leshchyshyn; Peter William Beaton; Thomas Michael Coolen - Web page: https://patentgrep.com/patent/US20130157904A1 ## CPC - C09K 8/68: containing organic compounds - C09K 8/685: {containing cross-linking agents} - C09K 8/703: {Foams} - C09K 8/80: Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open - C09K 8/88: macromolecular compounds - C09K 8/94: Foams - C09K 2208/26: Gel breakers other than bacteria or enzymes - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE ## Abstract The invention describes improved environmentally friendly, non-toxic, CBM friendly, green fracturing compositions, methods of preparing fracturing compositions and methods of use. Importantly, the subject invention overcomes problems in the use of water-based mists as an effective fracturing composition particularly having regard to the ability of a mist to transport an effective volume of proppant into a formation. As a result, the subject technologies provide an effective economic solution to using high ratio gas fracturing compositions that can be produced in a continuous (i.e. non-batch) process without the attendant capital and operating costs of current pure gas fracturing equipment. ## Claims ### Claim 1 A fracturing fluid composition for use in fracturing a coal bed methane formation comprising: a non-toxic and coal bed methane (CBM) friendly liquid component for temporarily supporting a proppant within the liquid component at surface, the liquid component including: i) a viscosified water component including a viscosifier, the viscosified liquid component having a viscosity sufficient to temporarily support proppant admixed within the viscosified water component; and ii) a breaker for relaxing the viscosity of the viscosified water component within a pre-determined period wherein the non-toxic liquid component passes toxicity testing. ### Claim 2 (depends on 1) The fracturing fluid composition as in claim 1 wherein the toxicity testing is a Microtox™ test. ### Claim 3 (depends on 2) The fracturing fluid composition as in claim 2 wherein the Microtox™ test is an EC50 test. ### Claim 4 (depends on 1) The fracturing fluid composition as in claim 1 wherein the toxicity testing includes the step of monitoring changes in the level of light emission from Vibrio fischeri NRRL-B-11177 when challenged with the non-toxic liquid component. ### Claim 5 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is any one of or a combination of hydroxyethyl cellulose (HEC), PAC (poly anionic cellulose) or a derivative thereof. ### Claim 6 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is a guar gum or a derivative thereof. ### Claim 7 (depends on 6) The fracturing fluid composition as in claim 6 wherein the viscosifier is a guar gum or a derivative thereof initially suspended in a non-toxic mineral oil. ### Claim 8 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is characterized as having zero or minimal residual solids after breaking. ### Claim 9 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is HEC and the HEC is characterized as having zero solids. ### Claim 10 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is HEC and is initially suspended in an isoparaffinic hydrocarbon. ### Claim 11 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is initially a dry powder. ### Claim 12 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is initially a dry powder and has a final concentration of 1-20 kg/m3 within the fracturing fluid composition. ### Claim 13 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosifier is initially a dry powder and has a final concentration of 3 kg/m3 within the fracturing fluid composition. ### Claim 14 (depends on 1) The fracturing fluid composition as in claim 1 wherein the viscosified water component includes 0.1-2.0 wt % gelling agent. ### Claim 15 (depends on 1) The fracturing fluid composition as in claim 1 wherein the breaker is an enzyme breaker. ### Claim 16 (depends on 15) The fracturing fluid composition as in claim 15 wherein the enzyme breaker is hemicellulase enzyme. ### Claim 17 (depends on 1) The fracturing fluid composition as in claim 1 wherein the concentration of breaker within the liquid component is sufficient to relax the initial viscosity of the liquid component to less than 10 cP at 170 sec−1 (20° C.) within 30 minutes. ### Claim 18 (depends on 1) The fracturing fluid composition as in claim 1 wherein the concentration of breaker within the liquid component is sufficient to relax the initial viscosity of the liquid component to less than 10 cP at 170 sec−1 (20° C.) within 10 minutes. ### Claim 19 (depends on 1) The fracturing fluid composition as in claim 1 wherein the concentration of breaker is greater than 0 and less 0.05% by weight. ### Claim 20 (depends on 1) The fracturing fluid composition as in claim 1 wherein the concentration of breaker is 0.005% by weight. ### Claim 21 (depends on 1) The fracturing fluid composition as in claim 1 wherein the water component contains saline water. ### Claim 22 (depends on 21) A fracturing fluid composition as in claim 21 wherein the saline water is derived from a dewatering process. ### Claim 23 (depends on 1) The fracturing fluid composition as in claim 1 wherein the water component is fresh water. ### Claim 24 (depends on 23) The fracturing fluid composition as in claim 23 wherein the fresh water is derived from a dewatering process. ### Claim 25 (depends on 1) The fracturing fluid composition as in claim 1 further comprising a proppant admixed within the viscosified water component. ### Claim 26 (depends on 25) The fracturing fluid composition as in claim 25 wherein the mass of proppant is 0.25-5.0 times the mass of the liquid component. ### Claim 27 (depends on 25) The fracturing fluid composition as in claim 25 wherein the mass of proppant is 1.0-2.5 times the mass of the liquid component. ### Claim 28 (depends on 1) The fracturing fluid composition as in claim 1 further comprising a gas component admixed with the liquid component under high turbulence conditions sufficient to support the proppant within a combined liquid component/gas component mixture wherein the combined liquid component/gas component mixture is characterized as a mist or liquid slug. ### Claim 29 (depends on 28) The fracturing fluid composition as in claim 28 wherein the gas component is carbon dioxide, nitrogen, or a mixture of carbon dioxide and nitrogen. ### Claim 30 (depends on 28) The fracturing fluid composition as in claim 28 wherein the combined fluid/gas component mixture is 3-15 vol % liquid component and 85-97 vol % gas component exclusive of the proppant. ### Claim 31 (depends on 1) The fracturing fluid composition as in claim 1 wherein the initial viscosity of the liquid component is 15-100 centipoise (cP) at 170 sec−1 prior to mixing with a proppant or a gas component. ### Claim 32 (depends on 1) The fracturing fluid composition as in claim 1 wherein each of the viscosifier, water and breaker components are individually and collectively non-toxic. ### Claim 33 (depends on 1) The fracturing fluid composition as in claim 1 further comprising a clay control agent. ### Claim 34 (depends on 1) The fracturing fluid composition as in claim 1 further comprising a non-toxic coal bed methane friendly clay control agent. ### Claim 35 (depends on 33) The fracturing fluid composition as in claim 33 wherein the clay control agent is diallyl dimethyl ammonium chloride (DADMAC). ### Claim 36 (depends on 1) The fracturing fluid composition as in claim 1 further comprising greater than 0 and less than 1 vol % clay control agent. ### Claim 37 (depends on 33) The fracturing fluid composition as in claim 33 wherein the clay control agent is KCL or naturally occurring salts thereof. ### Claim 38 (depends on 35) The fracturing fluid composition as in claim 35 wherein the clay control agent is greater than 0 and less than 0.75% (by weight). ### Claim 39 (depends on 1) The fracturing fluid composition as in claim 1 further comprising a non-toxic buffer. ### Claim 40 (depends on 1) The fracturing fluid composition as in claim 1 wherein the non-toxic buffer is less than 1 vol %. ### Claim 41 (depends on 39) The fracturing fluid composition as in claim 39 wherein the non-toxic buffer is an organic acid. ### Claim 42 (depends on 39) The fracturing fluid composition as in claim 39 wherein the non-toxic buffer is formic acid. ### Claim 43 A fracturing fluid composition for use in fracturing a coal bed methane formation comprising: a non-toxic and coal bed methane (CBM) friendly liquid component for temporarily supporting a proppant within the liquid component at surface, the liquid component including: a viscosified water component including a viscosifier, the viscosified liquid component having a viscosity sufficient to temporarily support proppant admixed within the viscosified water component wherein the viscosifier is any one of or a combination of hydroxyethyl cellulose (HEC), PAC (poly anionic cellulose) or a derivative thereof; and an enzyme breaker for relaxing the viscosity of the viscosified water component within a pre-determined period wherein the concentration of enzyme breaker within the liquid component is sufficient to relax the initial viscosity of the liquid component to less than 10 cP at 170 sec−1 (20° C.) within 30 minutes; wherein each of the viscosifier, water and breaker are individually and collectively non-toxic.