CA3079582A1 - Compositions and methods - Google Patents

Abstract

A composition comprising an alkali silicate and a biomolecule. The biomolecule is capable of delaying gelation of the alkali silicate for a period of time when in an aqueous medium. Methods of making the composition, methods of use of the composition and uses of the composition are also provided.

Description

COMPOSITIONS AND METHODS
Field The present disclosure relates to compositions comprising silicates. In particular, the present disclosure relates to compositions for delaying gelation of silicates, methods and uses therefor.
Background Hydrocarbon-bearing shale and coal seam formations are a rich source of natural oil and gas. Unfortunately, high water production at the beginning of the drilling operation in respect of, for example, Coal Seams Gas wells, may result in shale hydration when the shales come into contact with the water resulting in collapse of the shale layer. In addition, loose fines found in these formations and/or made by the drilling thereof can migrate within the formations to the drilling fluid thereby damaging operational equipment.
PCT Publication No. W02017200373 is directed to a method for treating a subterranean formation containing shale which includes introducing to the subterranean formation a shale stabilizer, a surfactant, and a triggering agent simultaneously with or prior to introducing an alkali silicate to the subterranean formation, and allowing the alkali silicate and triggering agent to react to form a reaction product. Coating the surface of at least a portion of the shale with the reaction product is also disclosed. However, the gelation of the silicate solution is substantially instantaneous and, due to the potential for misplaced interactions between the silicate and the triggering agent, the components of the composition would need to be transported and stored separately.
U.S. Patent No. 4799549 is directed to stable, gel-forming aqueous microemulsions, adopted for the reversible stabilization or plugging of soil/rock formations, e.g., subterranean well formations, the compositions comprised of (i) an aqueous solution of a water-soluble alkali metal silicate, (ii) a gelling reagent therefor, and (iii) at least one surface active agent. However, maintenance of the emulsion with the reservoir conditions is unpredictable and injection of an alkali silicate emulsion may pose certain difficulties such as slow propagation, and the risk of separation which could give rise to heterogeneous clogging.
A need, therefore, exists for the development of a composition and/or method that obviates or mitigates at least one of the disadvantages described above or that provides a useful alternative.

Date Recue/Date Received 2020-04-24 Summary In an aspect there is provided, a composition comprising an alkali silicate and a biomolecule, wherein the biomolecule is capable of delaying gelation of the alkali silicate for a period of time when in an aqueous medium.
In aspects, the delaying is related to the ratio of the biomolecule to the alkali silicate.
In aspects, the delaying is related to the type of biomolecule in the composition.
In aspects, when the composition is in contact with a subterranean formation, gelation of the alkali silicate is delayed.
In aspects, when the composition is in contact with a subterranean formation, the composition begins to gel after a period time.
In aspects, the biomolecule is capable of producing an alkaline aqueous composition when in the aqueous medium to delay gelation of the alkali silicate.
In aspects, the composition has an alkaline pH.
In aspects, the pH is about 8 to about 10.
In aspects, the pH is about 8.5 to about 9.5.
In aspects, the biomolecule is present in an amount of about 1% w/w to about 25% w/w.
In aspects, the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations thereof.
In aspects, the biomolecule comprises an amino acid selected from the group consisting of leucine, isoleucine, valine, methionine, tryptophan, phenylalanine, threonine, arginine, lysine, histidine, alanine, glycine, proline, glutamic acid, aspartic acid, asparagine, cysteine, glutamine, tyrosine, serine and mixtures thereof.
In aspects, the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.
In aspects, the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

2 Date Recue/Date Received 2020-04-24 In aspects, the biomolecule is an amino acid selected from arginine, histidine, lysine or mixtures thereof.
In aspects, the biomolecule is L-lysine.
In aspects, the delay is a partial, substantial or complete delay of gelation.
In aspects, the period of time is from after about 1 hour to after about 24 hours.
In aspects, wherein the period of time is after about 4 hours, or after about 6 hours, or after about 24 hours.
In aspects, the aqueous medium is selected from the group consisting of water, fresh water, distilled water, sea water, salt water, brine, mixtures of water and water soluble organic compounds, and mixtures thereof.
In aspects, the aqueous medium comprises water.
In aspects, the subterranean formation is selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.
In aspects, the subterranean formation comprises shale and/or coal seams.
In aspects, the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.
In another aspect, there is provided a composition comprising an alkali silicate and an amino acid.
In aspects, the composition comprises about 1 to about 40% w/w of the alkali silicate and about 1 to about 25% w/w of the amino acid.
In aspects, the amino acid is basic, such as arginine, histidine, lysine, or mixtures thereof.
In aspects, the amino acid is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.
In aspects, the amino acid is arginine, histidine, lysine or mixtures thereof.
In aspects, the amino acid is L-lysine.

3 Date Recue/Date Received 2020-04-24 In aspects, the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.
In aspects, the alkali silicate is potassium silicate.
In aspects, the composition further comprises an additive.
In aspects, the additive is present in an amount of about 1% w/w to about 20%
w/w.
In aspects, the additive is selected from the group consisting of a metallic salt and a surfactant.
In aspects, the metallic salt comprises potassium chloride.
In aspects, the surfactant is selected from the group consisting of a non-ionic surfactant, .. an anionic surfactant and a combination thereof.
In aspects, the composition is an aqueous composition.
In aspects, the aqueous composition is clear.
In aspects, the aqueous composition is slightly opaque.
In aspects, the aqueous composition is substantially free of particulate matter.
In another aspect, there is provided a composition as described herein for treating a subterranean formation penetrated by a wellbore.
In another aspect, there is provided a composition as described herein for delaying gelation of the alkali silicate in the aqueous medium.
In still another aspect, there is provided a use of the composition of as described herein treating a subterranean formation penetrated by a wellbore.
In still another aspect, there is provided a use of the composition as described herein for delaying gelation of the alkali silicate in the aqueous medium.
In yet another aspect, there is provided a method of treating a subterranean formation penetrated by a wellbore comprising injecting the composition as described herein into the subterranean formation.

4 Date Recue/Date Received 2020-04-24 In yet another aspect, there is provided a method of treating a subterranean formation penetrated by a wellbore comprising: providing an aqueous composition comprising an alkali silicate and a biomolecule; introducing the aqueous composition into the subterranean formation through a wellbore; and delaying gelation of the alkali silicate in the aqueous composition for a period of time.
In aspects, the delaying is related to the ratio of the biomolecule to the alkali silicate.
In aspects, the delaying is related to the type of biomolecule in the composition.
In aspects, the biomolecule is present in an amount of about 1% w/w to about 25% w/w.
In aspects, the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations/mixtures thereof.
In aspects, the biomolecule comprises an amino acid selected from the group consisting of leucine, isoleucine, valine, methionine, tryptophan, phenylalanine, threonine, arginine, lysine, histidine, alanine, glycine, proline, glutamic acid, aspartic acid, asparagine, cysteine, glutamine, tyrosine, serine and mixtures thereof.
In aspects, the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.
In aspects, the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.
In aspects, the biomolecule is an amino acid selected from arginine, histidine, lysine or mixtures thereof.
In aspects, the biomolecule is L-lysine.
In aspects, the period of time is about 1 hour to after about 24 hours.
In aspects, the period of time is after about 4 hours, or after about 6 hours, or after about .. 24 hours.
In aspects, the delaying is a partial, substantial or complete delayed gelation.
In aspects, the method further comprises passing the composition through the subterranean formation.

5 Date Recue/Date Received 2020-04-24 In aspects, the passing comprises using pores and/or cleats of the subterranean formation as passage conduits for the composition.
In aspects, the introducing comprises injecting the aqueous composition into the subterranean formation.
In aspects, the injecting is based on the calculated volume of the void space volume of the subterranean formation.
In aspects, the void space volume comprises a coal seam and an inter-burden shale layer.
In aspects, the method further comprises depositing the aqueous composition into the subterranean formation.
In aspects, the method further comprises flushing the wellbore with a post-flush solution.
In aspects, the post flush solution comprises 3% potassium chloride and optionally a surfactant.
In aspects, the method further comprises injecting a spacer fluid into the wellbore.
In aspects, the spacer fluid prevents gelation of the composition in a production zone of the subterranean formation.
In aspects, the method further comprises flushing the wellbore with a pre-flush solution.
In aspects, the pre-flush solution comprises 3% potassium chloride.
In aspects, the method further comprises putting the wellbore in shut-in position for a period of time.
In aspects, the period of time is about 1 hour to about 24 hours.
In aspects, the method further comprises controlling fines migration to the wellbore.
In aspects, the controlling comprises retarding movement of at least a portion of any fine particulate material moving to said wellbore from the formation through incorporation and/or adherence of the fines to the aqueous composition.
In aspects, the method further comprises stabilizing the subterranean formation.

6 Date Recue/Date Received 2020-04-24 In aspects, the stabilizing is related to the degree of penetration of the composition into the subterranean formation.
In aspects, the stabilizing is semi-permanent or permanent.
In aspects, the delaying allows for penetration into, and/or stabilization of the subterranean formation.
In aspects, the method further comprises allowing the composition to gel in the subterranean formation.
In aspects, the subterranean formation is selected from selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.
In aspects, the subterranean formation comprises shale and/or coal seams.
In aspects, the composition further comprises an additive.
In aspects, the additive is present in an amount of about 1% w/w to about 20%
w/w.
In aspects, the additive is selected from the group consisting of a metallic salt, a surfactant and a combination thereof.
In aspects, the metallic salt comprises potassium chloride.
In aspects, the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.
In aspects, the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.
In aspects, the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.
In aspects, the aqueous composition is clear.
In aspects, the aqueous composition is slightly opaque.
In aspects, the aqueous composition is substantially free of particulate matter.
In aspects, the aqueous composition has an alkaline pH.
In aspects, the aqueous composition has a pH of about 8 to about 10.

7 Date Recue/Date Received 2020-04-24 In aspects, the aqueous composition has a pH of about 8.5 to about 9.5.
In another aspect, there is provided a method of making a composition, comprising added a biomolecule to an aqueous medium, mixing the aqueous medium to form an aqueous composition, and adding an alkali silicate to the aqueous composition.
In aspects, the mixing is continuous to form an aqueous solution of the aqueous composition.
In aspects, the aqueous composition is clear.
In aspects, the aqueous composition is slightly opaque.
In aspects, the aqueous composition is substantially free of particulate matter.
In aspects, the biomolecule is present in an amount of about 1% w/w to about 25% w/w.
In aspects, the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations thereof.
In aspects, the amino acid is basic, such as arginine, histidine, lysine, or mixtures thereof.
In aspects, the amino acid is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.
In aspects, the amino acid is arginine, histidine, lysine or mixtures thereof.

In aspects, the amino acid is L-lysine.
In aspects, the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.
In aspects, the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.
In aspects, the composition further comprises added an additive to the aqueous composition.
In aspects, the additive is present in an amount of about 1% w/w to about 20%
w/w.
In aspects, the additive is selected from the group consisting of a metallic salt, a surfactant and a combination thereof.

8 Date Recue/Date Received 2020-04-24 In aspects, the metallic salt comprises potassium chloride.
In aspects, the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.
In aspects, the aqueous composition has an alkaline pH.
In aspects, the pH is about 8 to about 10.
In aspects, the pH is about 8.5 to about 9.5.
In another aspect, there is provided a composition obtained by the method described herein.
In yet another aspect, there is provided a composition comprising an alkali silicate and a biomolecule, wherein the biomolecule controls gelation time of the alkali silicate in an aqueous medium.
In aspects, the biomolecule controls gelation time of the alkali silicate in the presence of a subterranean formation.
In aspects, the biomolecule is an amino acid.
In aspects, the biomolecule is a combination of amino acids selected to achieve a desired gelation time.
In aspects, the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.
In aspects, the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.
In aspects, the biomolecule is L-lysine.
In aspects, the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.
In aspects, the alkali silicate is potassium silicate.
In aspects, the composition further comprises an additive.
In aspects, the additive is present in an amount of about 1% w/w to about 20%
w/w.

9 Date Recue/Date Received 2020-04-24 In aspects, the additive is selected from the group consisting of a metallic salt and a surfactant.
In aspects, the metallic salt comprises potassium chloride.
In aspects, the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.
In aspects, the composition is an aqueous composition.
In aspects, the aqueous composition is clear.
In aspects, the aqueous composition is slightly opaque.
In aspects, the aqueous composition is substantially free of particulate matter.
In aspects, the aqueous composition has an alkaline pH.
In aspects, the pH is about 8 to about 10.
In aspects, the pH is about 8.5 to about 9.5.
In aspects, the subterranean formation is selected from selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.
In aspects, the subterranean formation comprises shale and/or coal seams.
In another aspect, there is provided a composition as described herein for delaying gelation of the alkali silicate in the aqueous medium.
In another aspect, there is provided a use of the composition as described herein for treating a subterranean formation penetrated by a wellbore.
In another aspect, there is provided a use of the composition as described herein for delaying gelation of the alkali silicate in the aqueous medium.
In another aspect, there is provided a method of treating a subterranean formation penetrated by a wellbore comprising injecting the composition as described herein into the subterranean formation.
Date Recue/Date Received 2020-04-24 The novel features of the present invention will become apparent to those of skill in the art upon examination of the following detailed description of the invention.
It should be understood, however, that the detailed description of the invention and the specific examples presented, while indicating certain aspects of the present invention, are provided for illustration purposes only because various changes and modifications within the spirit and scope of the invention will become apparent to those of skill in the art from the detailed description of the invention and claims that follow.
Brief Description of the Drawings The present invention will be further understood from the following description with reference to the Figures, in which:
Figure 1 shows a top view of an Australian shale core with coal anomaly used in Example 3.
Figure 2 shows a perspective view of the following solutions, prior to gelation, from left to right, a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, a solution of lysine and silicate in accordance with the present invention without the shale core of Figure 1 and a solution of arginine, glycine and silicate in accordance with the present invention, without the shale core of Figure 1.
Figure 3 shows a perspective view of, from left to right, a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, and a solution of lysine and silicate in accordance with the present invention without the shale core of Figure 1.
Figure 4 shows a perspective view of, on the left, a solution of arginine, glycine and silicate in accordance with the present invention without the shale core of Figure 1, gelled after about 6 hours.
Figure 5 shows a top view of a solution of arginine and silicate in accordance with the present invention with the shale core of Figure 1, not gelled after about a week.
Figure 6 shows a side view of the arginine and silicate solution of Figure 5.
Figure 7 shows a top view of a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, not gelled after about 4 hours.
Figure 8 shows a side view of a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, about to gel after about 6 hours.

Date Recue/Date Received 2020-04-24 Figure 9 shows a side view of a solution of lysine silicate in accordance with the present invention with the shale core of Figure 1, from left to right, gelled after about 24 hours and about to gel, respectively.
Figure 10 shows a perspective view of a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, from left to right, gelled after about 24 hours and not gelled, respectively.
Figure 11 shows a top view of a solution of lysine and silicate in accordance with the present invention with the shale core of Figure 1, gelled after about 24 hours.
Detailed Description Definitions Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present invention, the typical materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used.
The term "additive" means an ancillary ingredient that can be added to the compositions described herein. Examples of additives would be understood by persons skilled in the art, and some examples are provided in the description below.
"Treating" generally refers to an approach for obtaining beneficial or desired results. For example, "treating," in aspects, refers to ameliorating, reversing, alleviating, inhibiting the progress of, or preventing, for example, disruption (instability) of a shale layer and/or loose fines migration in a subterranean formation.
"Treatment" refers to the act of "treating" as defined immediately above.
Forms of "shale instability" include, but are not limited to, shale swelling, dispersing, migration, swelling-induced migration, and the like, which can adversely impact drilling operations.
The term "shale" it is meant to refer to a fine-grained sedimentary rock formed by the consolidation of clay, silt, or mud. It is characterized by a finely laminated structure which imparts fissures parallel to the bedding along which the rock may easily break.
"Subterranean formation" may include any geology, including at least a sandstone, limestone, dolomite, shale, coal seam, tar sand, and/or unconsolidated formation. The formation Date Recue/Date Received 2020-04-24 may be fluidly coupled to a wellbore, which may be an injector well, a producer well, and/or a fluid storage well. The wellbore may penetrate the formation vertically, horizontally, in a deviated orientation, or combinations of these. The wellbore may be a single wellbore, a set of wellbores directionally deviated from a number of close proximity surface wellbores (e.g. off a pad or rig) or single initiating wellbore that divides into multiple wellbores below the surface.
The term "delay" refers to partially, substantially, or completely slowing, hindering, reducing, inhibiting or preventing. The terms inhibit, reduced, prevented, delayed, and slowed may be used interchangeably.
When introducing elements disclosed herein, the articles "a", "an", "the", and "said" are intended to mean that there may be one or more of the elements.
Any range described herein is understood to include any incremental ranges or individual values therebetween.
In understanding the scope of the present application, the term "comprising"
and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps.
The foregoing also applies to words having similar meanings such as the terms, "including", "having" and their derivatives. It will be understood that any embodiments described as "comprising" certain components may also "consist of" or "consist essentially of," wherein "consisting of" has a closed-ended or restrictive meaning and "consisting essentially of" means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effects described herein. For example, a composition defined using the phrase "consisting essentially of" encompasses any known pharmaceutically acceptable additive, excipient, diluent, carrier, and the like. Typically, a composition consisting essentially of a set of components will comprise less than 5% by weight, typically less than 3% by weight, more typically less than 1%
by weight of non-specified components.
It will be understood that any component defined herein as being included may be explicitly excluded from the claimed invention by way of proviso or negative limitation, such as any specific compounds or method steps, whether implicitly or explicitly defined herein. For example, in other aspects of the invention the biomolecule described herein is not glycine, alone, but glycine may be combined with another biomolecule within the scope of the invention (e.g. with another amino acid such as arginine and/or lysine) In addition, all ranges given herein include the end of the ranges and also any Date Recue/Date Received 2020-04-24 intermediate range points, whether explicitly stated or not.
Finally, terms of degree such as "substantially", "about" and "approximately"
as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least 5% of the modified term if this deviation would not negate the meaning of the word it modifies.
The abbreviation, "e.g." is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation "e.g." is synonymous with the term "for example." The word "or" is intended to include "and" unless the context clearly indicates otherwise.
The phrase "at least one of" is understood to be one or more. The phrase "at least one of... and..." is understood to mean at least one of the elements listed or a combination thereof, if not explicitly listed. For example, "at least one of A, B, and C" is understood to mean A alone or B alone or C alone or a combination of A and B or a combination of A and C or a combination of B and C or a combination of A, B, and C. "At least one of at least one of A, at least one of B, and at least one of C" is understood to mean at least one of A alone or at least one of B alone or at least one of C alone or a combination of at least one of A and at least one of B or a combination of at least one of A and at least one of C or a combination of at least one of B and at least one of C or a combination of at least one of A, at least one of B, and at least one of C.
Compositions Compositions for delaying gelation of alkali silicates are provided herein.
The compositions described herein are typically stable and may avoid premature gelation of the alkali silicate. Moreover, the compositions are such that a biomolecule is capable of controlling the timeframe of delay, for example, an amount of time required before the composition becomes a gel.
In general, a composition comprises an alkali silicate and a biomolecule, wherein the biomolecule is capable of delaying gelation of the alkali silicate for a period of time when in an aqueous medium. In other embodiments, the composition is an aqueous composition. In this way, an aqueous composition comprising the alkali silicate and the biomolecule, wherein the biomolecule is capable of delaying gelation of the alkali silicate is also contemplated herein.
The period of time of the delayed gelation of the alkali silicate may be dependent on, for example, pH of the solution, the type of biomolecule used, concentrations of the biomolecule and/or the alkali silicate, and/or the ratios of the biomolecule to the alkali silicate. In typical Date Recue/Date Received 2020-04-24 embodiments, the delaying is related to the ratio of the biomolecule to the alkali silicate. In other typical embodiments, the delaying is related to the type of the biomolecule in the composition.
The delaying may also be a partial, substantial or complete delay of gelation of the alkali silicate. The shorter the timeframe of delay generally equates to the degree of delay of gelation, such that the delay is partial, substantial or complete. For example, if the gelation of the alkali silicate takes place after about a few minutes to about a few hours, the gelation may be considered partially delayed. For example, this may include delayed gelation of about 1 minute, 2 minutes, 3 minutes, 4 minutes or 5 minutes to about 1 hour, 2 hours, 3 hours or 4 hours. If the gelation took place after about 5 hours to about 24 hours, gelation was substantially delayed.
For example, delayed gelation of about 5 hours, 6 hours, 10 hours, 12 hours, 16 hours or about 24 hours. If the gelation does not occur, it is understood that the gelation is completely delayed.
In specific embodiments, the gelation is delayed for about 1 hour to about 24 hours. In further specific embodiments, the gelation is delayed until about 4 hours, about 6 hours, or up to about 24 hours, depending on, for the example, the biomolecule used in the composition.
The time-delayed gelation imparted by the biomolecule may be controlled by varying, for example, the pH of the composition comprising the alkali silicate and the biomolecule. For example, the biomolecule used herein is capable of producing an alkaline composition when in the aqueous medium (e.g. producing an aqueous alkaline composition). This may control the time required to gelation. Time-delayed gelation may occur at a pH range of about 8 to about

10, or at a pH range of about 2 to about 5. In typical embodiments, the compositions described herein have an alkaline pH. In typical embodiments, the pH is about 8 to about 10, such as about 8, about 9 or about 10, to allow for time-delayed gelation of the alkali silicate. In other embodiments, the compositions described herein have a pH of about 2 to about 5, such as about 2, about 3, about 4, or about 5, to allow for time-delayed gelation of the alkali silicate.
The time-delayed gelation imparted by the biomolecule may be controlled by varying, for example, the ratio of the biomolecule to the alkali silicate. For example, the biomolecule and the alkali silicate may be used in a ratio of, for example, from about 1:50 to about 50:1, such as from about 1:50, about 1:35, about 1:25, about 1:20, about 1:15, about 1:10, about 1:9, about 1:8, about 1:7, about 1:6, about 1:5, about 1:4, about 1:3, about 1:2, or about 1:1 to about 2:1, about 3:1, about 4:1, about 5:1, about 6:1, about 7:1, about 8:1, about 9:1, about 10:1, about 15:1, about 20:1, about 25:1, about 35:1, or about 50:1.
The alkali silicate is, in aspects, nontoxic and/or biodegradable (e.g. break down into benign, naturally occurring products) and may therefore be beneficial to the environment: both on-land (e.g. being disposable through mix-bury cover, land spreading or land spraying) and offshore (e.g. being able to be discharged into the ocean), as an oilfield chemical. In addition, Date Recue/Date Received 2020-04-24 the alkali silicate may be able to withstand harsh reservoir environments, such as those having temperatures exceeding about 150 C, whereas other molecules may not be well suited. As understood in the art, the alkali silicate may be defined by silica-to-alkali "ratios" (e.g. in the case of sodium silicate, Si02:Na20 weight ratios or in the case of potassium silicate, Si02:K20 weight ratios). This ratio can play a role in gelation of the alkali silicate, such that, for example, wherein "M" is an alkali metal, the higher the Si02:M20 ratio, the sooner the gelation. Typical ratios are in the range of about 1 to about 4, and more typical ratios are between about 2 to about 4. It is understood that mixtures of the alkali silicates with different molar ratios and/or different alkali metals is within the scope of the present invention.
The alkali silicate may be a silicate or a polysilicate of one or more alkali metals. The alkali silicate may be selected from lithium silicate, sodium silicate, potassium silicate, rubidium silicate, cesium silicate, francium silicate and mixtures thereof. In typical embodiments, the alkali silicate is potassium silicate, sodium silicate, lithium silicate or cesium silicate. In more typical embodiments, the alkali silicate is potassium silicate. In typical embodiments, the alkali silicate is potassium silicate having a Si02:K20 ratio ranging from about 1 to about 4.
In a more typical embodiment, the alkali silicate is potassium silicate having a Si02:K20 ratio of more than about 2. The alkali silicate may be, for example, in the form of a liquid or as a spray-dried soluble powder dissolvable in a liquid to form a solution. Typically, the alkali silicate is dissolvable to form a solution that has an alkaline pH, such as form about 10 to about 13.
The alkali silicate .. may be present in the composition in any amount, typically from about 1% to about 40% by weight, such as from about 1%, 5%, 10%, 15%, 20%, 25%, 30%, or 35% to about 2%,5%, 10%, 15%, 20%, 25% 30%, 35% or 40% by weight.
Typically, the biomolecule is a biodegradable (e.g. having a positive environmental footprint) modulator that may be naturally occurring, recombinant, or synthetic, or any combination thereof. In addition to imparting the delayed gelation of the alkali silicate, the biomolecule is capable of forming an alkaline composition when dissolved the aqueous medium.
For example, the biomolecule is capable of forming an alkaline composition (e.g. an aqueous alkaline composition) having a pH of about 7 to about 10, such as about 7, about 8, about 9, or about 10. In typical embodiments, the biomolecule forms an alkaline composition (e.g. an aqueous alkaline composition) having a pH in the range of about 8.5 to about 9.5. The biomolecule may be, for example, amino acids, esters thereof, analogs thereof (e.g. structural isomers of amino acids, such as, but not limited to L ¨ citrulline, methyllysine, homoarginine, S-(2-Aminoethyl)cysteine, Canavanine and 3-(Aminoethyl)cyclohexaneglycine), oligomers thereof (e.g. oligiomer of L-lysine), peptides, polypeptides and combinations/mixtures thereof.

Date Recue/Date Received 2020-04-24 Typically, the biomolecule is an amino acid. The amino acid can be, for example, essential amino acids (e.g. leucine, isoleucine, valine, methionine, tryptophan, phenylalanine, threonine, arginine, lysine and histidine), non-essential amino acids (e.g.
alanine, glycine, proline, glutamic acid, aspartic acid, asparagine, cysteine, glutamine, tyrosine, and serine) and combinations/mixtures thereof. The amino acid can be an alpha (a)- beta (13)-, L-, D-, or DL-amino acid. The amino acid can be any mixture or combination thereof.
In other embodiments, the amino acid is selected from arginine, lysine, histidine, or any combination/mixture thereof. In typical embodiments, the amino acid is arginine, lysine or combination/mixture thereof. In more typical embodiments, the amino acid is lysine. In further typical embodiments, the amino acid is L-lysine. In other embodiments, the biomolecule is a combination of amino acids selected to achieve a desired gelation time. In other embodiments, biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof. In other embodiments, the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof. In typical embodiments, the .. amino acid is present in an amount of from about 1% w/w to about 25% w/w.
The amino acid may be present in an amount of from about 1%, about 4%, about 10%, about 15%, or about 20%, to about 2%, about 6%, about 12%, about 17%, or about 25% (w/w). For example, compositions comprising arginine and/or lysine typically comprise about 15%
arginine or lysine, by weight.
The aqueous media may be selected from, for example, water, fresh water, distilled water, sea water, salt water, brine (e.g. an alkali salt in water), mixtures of water and water soluble organic compounds, and mixtures thereof. In typical embodiments, the aqueous medium comprises water. In more typical embodiments, the aqueous medium is water.
When the alkali silicate and the biomolecule are dissolved in the aqueous medium, the resulting composition is an aqueous composition. In typical embodiments, the aqueous composition is a clear, homogenous solution of the alkali silicate and the biomolecule. In this way, the aqueous composition is substantially free of particulate matter. In other embodiments, the aqueous composition is free of particulate matter.
In other embodiments, the compositions described herein may further comprise an additive. The additives are typically neutral to the delaying effect imparted by the biomolecule described herein. Additives, as understood in the art, may be, for example, fluid loss control agents, weighting materials, viscosifying agents, dispersants, lubricants, corrosion inhibitors, defoamers, metallic salts, and surfactants. In typical embodiments, the additive is selected from metallic salts and surfactants. The additive may be present in the composition in any amount, typically from about 1% to about 20% by weight, such as from about 1%, 5%, 10%, or 15%, to Date Recue/Date Received 2020-04-24 about 5%, 10%, 15% or 20% by weight. More typically, the additive is present from about 1% to about 5% by weight.
Examples of metallic salts include, but are not limited to, chlorides, nitrates or sulfates of potassium and combinations thereof. The surfactants may be zwitterionic surfactants, amphiphilic surfactants, cationic surfactants, anionic surfactants, non-ionic surfactants, or combinations thereof. In typical embodiments, the surfactants are non-ionic or anionic. When added to the compositions herein, the surfactant may aid in controlling the thickness of the silicate gel, in binding of the silicate gel to the shale and/or in binding the composition to the fines in the subterranean formation. Examples of suitable surfactants within the scope of the invention would be readily discernible by those of skill in the art, and may include, but is not limited to, glyceryl fatty esters, such as glyceryl stearate, polyglycery1-2 laurate, polyglycery1-2 oleate; sorbitan fatty esters, such as sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan monooleate, sorbitan trioleate, and (polyethylene) derivatives thereof (e.g. polyoxyethylene (20) sorbitan monooleate (polysorbate 80)), polyethylene glycol (PEG) and derivatives, such as PEG-200, PEG-6000 stearate, PEG-400 distearate PEG-300 oleate, PEG-200 dioleate or combinations/mixtures thereof.
The compositions described herein are typically stable compositions (e.g.
aqueous compositions) that can reduce premature gelation of the alkali silicate. This is particularly advantageous in that, in aspects, the biomolecule of the compositions described herein is selectively reactive (e.g. allows for time-dependent gelation of the alkali silicate), when in the presence of subterranean formations (e.g. shale and/or coal seams), such that when the compositions described herein are not in the presence of the subterranean formation, the compositions described herein are stable and ready for use as described below.
Moreover, the compositions are such that, depending on, for example the type of biomolecule used in the composition, the biomolecule is capable of controlling the time to gelation (e.g. delays gelation), such as for example, delayed gelation until after about 6 hours, or delayed gelation after about 24 hours. Moreover, the compositions described herein are easily handled and may be injected into dense terrains or into finely porous rock formations due to their low initial viscosity (e.g. the pre-gel form of the composition). It would be understood that the viscosity would increase until the gel is formed, after the appropriate period of time for delayed gelation has passed.

Date Recue/Date Received 2020-04-24 Methods of Making the Compositions Methods of making the compositions described herein are provided. In general, the method comprises adding the biomolecule to the aqueous medium, mixing the biomolecule in the aqueous medium to form a solution, and adding an alkali silicate to the solution.
The biomolecule may be added to the aqueous medium while mixing to form the solution. The biomolecule may be added to the aqueous medium and then the mixture is mixed to form the solution. In other embodiments, the mixing is continued until the solution is at least partially clear or is slightly opaque. Typically, the mixing is continued until the solution is clear. In typical embodiments, the solution is mixed until the solution is a clear and homogenous solution, such that there is no particulate matter visible in the solution. Following the addition of the biomolecule, the alkali silicate is added while mixing. The alkali silicate may be added to the solution (comprising the biomolecule) and then the solution is mixed. In some embodiments, the mixing results in a solution that is at least partially clear or is slightly opaque. Typically, the mixing is continued until the solution is clear. In typical embodiments, the mixing is continued until the resulting solution is a clear and homogenous solution, such that there is no particulate matter visible in the solution. Following this, further aqueous medium is added to the biomolecule-alkali silicate solution to provide a desired final volume for the solution. In typical embodiments, the biomolecule-alkali silicate solution is a clear, homogenous solution, with no particulate matter visible in the solution. In alternative embodiments, the alkali silicate is added to the aqueous medium prior to the addition of the biomolecule. In this way, the order of addition of the components (e.g. the alkali silicate and the biomolecule) of the compositions described herein can be varied.
In typical embodiments, the aqueous medium is selected from, for example, water or brine, and more typical embodiments, the aqueous medium comprises water. In other typical embodiments, the aqueous medium is water. In other embodiments, the biomolecule is in the form of a powder that is added to, and dissolvable in, the aqueous medium. In other embodiments, the alkali silicate is in the form of a powder that is added to, and dissolvable in, the aqueous medium. In other embodiments, the biomolecule is an amino acid or a combination of amino acids. In typical embodiments, the amino acid is selected from lysine, arginine or a combination thereof. In more typical embodiments, the amino acid is lysine, such as L-lysine. In other embodiments, the alkali silicate is in the form of a powder that is added to, and dissolvable in, the aqueous medium. In other embodiments, the alkali silicate is a combination of alkali silicates, for example a mixture of sodium silicate and potassium silicate. In typical embodiments, the alkali silicate is potassium silicate. The biomolecules and the alkali silicates Date Recue/Date Received 2020-04-24 are added to the compositions described herein in the amounts described herein. In further embodiments, the method further comprising added the additives described herein, in the amounts described herein.
When making the compositions described herein the viscosity of the composition (e.g.
.. premature gelling) may be controlled so as to avoid premature gelling of the composition as this may directly affect the use of the composition during the treatment process.
The methods described here produce typically stable compositions, wherein the biomolecules described herein (e.g. amino acids arginine and/ or lysine), are capable of delaying gelation of the alkali silicate when in an aqueous medium (e.g. as an aqueous compositions described herein) and/or .. when the composition is in contact with a subterranean formation.
Monitoring and/or controlling the viscosity of the compositions described herein (and providing compositions with delayed gelation) is advantageous in respect of the fact that if the composition is too viscous, the composition may have difficulty moving through the pores and cleats of the subterranean formation (e.g. coal seam) as premature gelation could block passage of the composition therethrough.
Methods and Uses of the Compositions Methods of treating subterranean formations penetrated by a wellbore using the compositions described herein and uses of the compositions described herein for treating subterranean formations is provided herein. Uses of the composition described herein for delaying gelation of the alkali silicate in the aqueous medium are also provided. The delayed gelation of the compositions described herein may stabilize the subterranean formation and/or control the migrations of the loose fines in the subterranean formation and/or created by the drilling procedures, thereby reducing the need for additional treatment steps and/or increasing costs associated with impacted drilling equipment.
As understood, shale exposed to, for example, aqueous-based drilling fluids may degrade resulting in undesirable drilling conditions and instability of the shale layer. Moreover, fines, found in the subterranean formation, and/or produced by drilling operations thereof tend to move or migrate to the well bore during the recovery of formation fluids which may result in, for example, blockage of the passageways leading to the well bore and/or passage through, and damage of, the operational equipment used to recover the hydrocarbons. By delayed gelation of the alkali silicate compositions described herein, methods and uses of stabilizing subterranean formations (e.g. shale layers) which are sensitive to the aforementioned degradation and/or controlling migration of fines may be provided by, for example, penetrating the subterranean Date Recue/Date Received 2020-04-24 formation and/or limiting mobility of the fines (e.g. by incorporating the fines into and/or adhering the fines to the compositions described herein) when the composition is injected into the subterranean formation.
The compositions described herein can be used to treat, or as a treatment solution for, subterranean formations. The composition described herein may be used in respect of newly drilled wells or for workover of existing wells (e.g., remedial fracturing of a well that has been producing for some time and has already been fractured in the past). The treatment uses and methods described herein may result in improved stability of the subterranean formation and/or the reduction in fines migrations. In general, a method of treating a subterranean formation comprises providing the aqueous composition comprising the biomolecule and the alkali silicate, introducing (e.g. injecting) the aqueous composition into the subterranean formation through a wellbore, and delaying gelation of the alkali silicate for a period of time.
In typical embodiments, the period of time is about 1 hour to about 24 hours, and it more typical embodiments, the period of time is after about 4 hours, after about 6 hours or after about 24 hours.
In typical embodiments, the composition is injected into the subterranean formation.
When the compositions described herein are contacted by subterranean formations (e.g. shale and/or coal seams), the biomolecule is capable of delaying gelation, in for example, a time-dependent manner. In some embodiments, the biomolecule may be able to control the gelation of the alkali silicate, when the composition is in the presence of shale. In some embodiments, the biomolecule may be able to control the gelation of the alkali silicate, when the composition is in the presence of coal seams. The subterranean formation can be, for example, sandstone, limestone, dolomite, shale, coal seam, tar sand, and/or unconsolidated formation. The subterranean formation may also be a coal bed methane formation comprising at least two coal bed seams and at least one shale inter-burden comprising shale located between the coal bed seams. In typical embodiments, the subterranean formation comprises shale and/or coal seams.
In other embodiments, the subterranean formation is shale and/or coal seams.
Typically, the compositions described herein are prepared by the methods described herein and brought to the wellbore. Advantageously, since the composition provides the necessary components to impart gelation delay in a single stable composition, there is no need, for example, to have separate handling facilities or transportation means the different components of the composition when the composition is required for treatment of the subterranean formation. In this way, the compositions described herein may provide a pre-formed mixture (e.g. solution), ready for use at the drilling operation site.
In some embodiments, flushing with a pre-flushing solution comprising, for example, 3%
potassium chloride solution may be conducted prior to the injecting step.
Volumes of the Date Recue/Date Received 2020-04-24 compositions used in the treatment method may depend on, for example, the overall formation and production zone holdup capacities as would be understood in the art.
Injection volume is selected based on the total calculated volume of void space, including the coal seams and the inter-burden shale layers, as would be understood, and readily calculated by those of skill in the art. During the injecting step, the compositions described herein may travel through, for example, pores and cleats made through perforations in coal seams. In this way, the pores and cleats may be used as passage conduits for the compositions described herein such that the composition is passed through the subterranean formation and deposited therein. In view of this, the viscosity of the compositions may be controlled or monitored while the compositions are being made so as to avoid premature gelation that may block passage of the composition through the coal seams and thereby, potentially negatively affect the production.
After finishing the injection of the composition, a post-flush solution may be used to flush out the composition from the coal seams. The post-flush solution comprises, for example, 3%
potassium chloride and a water wetting non-ionic or anionic surfactant. The volume of the post-flush solution may be based on calculated void space volumes of the coal seams, as would understood, and can be readily calculated by those of skill in the art.
Typically, it should be within about 10 to about 50% of the volume of the compositions described herein. After the injection of the compositions described herein, a spacer solution may be run to prevent gelation of the composition, and/or remove gelled compositions within the production zone. Spacers fluids suitable for use as described herein would be readily discernable by those of skill in the art.
After the treatment is finished and depending on the delaying mechanism employed (e.g.
a lysine and silicate solution or an arginine and silicate solution, or mixtures thereof), delayed gelation of the silicate solution takes place. In typical embodiments, when the compositions described herein are contacted by and/or in contact with the subterranean formations described herein (e.g. shale and/or coal seams), the biomolecule is capable of delaying gelation of the alkali silicate in the compositions described herein (e.g. aqueous composition), in for example, a time-dependent manner. In this way, the compositions described herein are reactive (e.g. forms a gel) in the presence of the subterranean formation. In some embodiments, the biomolecule may be able to control the gelation of the alkali silicate, when the composition is in the presence of shale. In some embodiments, the biomolecule may be able to control the gelation of the alkali silicate, when the composition is in the presence of coal seams. In this way, in aspects, the biomolecule may be able to selectively control the gelation of the alkali silicate when in the presence of a particular subterranean formation. Advantageously, in aspects, the biomolecule described herein may initiate/control gelation of the alkali silicate when in the presence of the Date Recue/Date Received 2020-04-24 subterranean formation, such that the stability of the composition (e.g. lack of premature gelling), prior to injection, may be maintained. In this way, after contact with the subterranean formation (e.g. deposition of the composition into the subterranean formation), the injected composition can be given the time required for gelation, such that the composition gels after the required amount of time has lapsed. For example, the delayed gelation may require about 1 hour to about 24 hours of time. In other embodiments, gelation takes place after about 1 hour, after about 4 hours, after about 6 hours, after about 10 hours, after about 15 hours, after about 20 hours, or after about 24 hours. In typical embodiments, the composition gels within about 6 hours and in other typical embodiments, the composition gels within about 24 hours. During the period of time where the composition is allowed to gel, the well may be kept in a shut-in position, such that production can begin after this shut-in period. Typically, the shut-in period is up to about 24 hours. Advantageously, the compositions described herein allow for controlled time-delay of the gelling of the composition, such that the user may therefore select a composition (based on the time requirements of the drilling operation) for use in the reservoir.
For example, not only may the delay be useful in allowing the composition to make its way through the pores and cleats as described above, but for drilling operations that require a shorter shut-in period, a composition having a shorter delay-time would help keep the operation running in a timely manner.
The compositions described herein may be useful for controlling and/or reducing fines migration and/or stabilizing the subterranean formation. When the composition is injected into the subterranean formation, as described above, the time-delay to gelation imparted by the biomolecule, may result in a control of fines migration to the wellbore. For example, the composition may be able to control fines migration through a reduction in the movement of at least a portion of the fines moving to the wellbore from the formation, by for example, adhering the fines to the composition and/or incorporating the fines into the composition. In this way, elimination or substantial reduction in the amounts of the fines may result in reduced contamination of the fluid flowing in the wellbore, when the well is in production.
Advantageously, the degree of delay (e.g. the amount of time required for the composition to gel) may control the degree of penetration into, and/or the degree of stabilization possible in respect of the subterranean formation. For example, a composition having a longer time delay of gelation may be able to penetrate deeper into the subterranean formation (e.g.
through the pores and cleats) than a composition with a shorter time of delay to gelation.
Increasing the depth of penetration into the subterranean formation, may increase the stability of the formation. In this way, the degree of stabilization may be related to the degree of penetration of the compositions into the subterranean formation. In other embodiments, the stabilization is Date Recue/Date Received 2020-04-24 permanent. In other embodiments, the stabilization is semi-permanent.
Moreover, not only do the compositions, when in contact with the subterranean formation, retain their ability to delay gelation, but the contacted subterranean formation (e.g. shale layer) do not typically suffer from any disruption to the structural integrity thereof. In this way, the formation does not breakdown in the presence of the composition (e.g. when the composition is passed through and/or deposited therein) but the formation remains at least substantially intact. In other embodiments, the formation remains fully intact.
The above disclosure generally describes the present invention. A more complete understanding can be obtained by reference to the following specific Examples.
These Examples are described solely for purposes of illustration and are not intended to limit the scope of the invention. Changes in form and substitution of equivalents are contemplated as circumstances may suggest or render expedient. Although specific terms have been employed herein, such terms are intended in a descriptive sense and not for purposes of limitation.
EXAMPLES
EXAMPLE. 1 Treatment Composition A 1 L solution was prepared by the following method. A beaker was filled with 500 mL of water and 50 g of L-Lysine was added. The combination was mixed until a clear solution was formed. To this resulting solution, 200 g of KASILTM 33 (i.e. potassium silicate) was added, and the solution of L-Lysine and potassium silicate was mixed until a homogenous, clear solution was formed. At this point, water was added to make a 1 L final solution.
EXAMPLE 2. Delayed Gelation Study without Shale Core Chips.
An experiment to test time dependent delay of gelation using the compositions described herein was conducted. Shale core chips shown in Figure 1 were omitted from the testing container/solution. The turbidity, viscosity and gelation of the composition was visually inspected. Photographs of the solutions were taken periodically. The time to gelation, if it happened, was recorded.
A 20% solution of potassium silicate (i.e. KASILTM 33) was prepared in water, with a total quantity of potassium silicate being approximately 7.2%. About 20 g of this solution was placed in a container and 10 g of 15% by weight solution of glycine was added. This solution turned into a gel within a few minutes. The same experiment was repeated with L-arginine and L-lysine Date Recue/Date Received 2020-04-24 with 10 g of 15% by weight solutions of each added to the potassium silicate solution. The solution treated with glycine turned into a gel within a few minutes (data not shown), however, as shown in Figures 2 and 3, the solutions with arginine (Figure 2 rightmost solution) and Lysine (Figure 2, solution in the middle and Figure 3, solution to the right) remained a liquid.
In another example, a solution was prepared by placing 30 g of the potassium silicate solution prepared above in a container. To this potassium silicate solution, about 10 g of 15%
arginine was added, followed by the addition of about another 10 g of 20%
glycine solution. As shown in Figure 4 (right), this solution turned into a gel within 6 hours.
EXAMPLE 3. Delayed Gelation Study with Shale Core Chips.
An experiment to test time-dependent delay of gelation using compositions described herein was conducted. Shale core chips (Figure 1) were included the testing container/solution, to repeat the experiments of Example 2 and determine the effect of the composition on shale integrity and in respect of the delayed gelation observed above. The turbidity, viscosity and gelation of the composition was visually inspected. The time to gelation, if it happened, was recorded. The physical state of the shale sample was inspected and the solutions were photographed periodically.
Shale core chips were added to the arginine or lysine containing solutions prepared in Example 2. The results of the experiments are shown in Figures 5 and 6 for the arginine solutions and Figures 7-11 for the lysine solutions. As shown in Figures 5 and 6 (the solution to the left), in the presence of the shale chips, the arginine solution remained a liquid. This was visible for up to about a week. As shown in Figures 7-11, in the presence of the shale chips, the lysine solution was converted into a gel after about 24 hours.
Specifically, as shown in Figure 7, the lysine and silicate solution was not gelled after about 4 hours. In Figure 8, after about 6 hours, the lysine and silicate solution was about to gel.
In Figure 9, the lysine and silicate solution to the right is shown as just about ready to gel (e.g.
at 6 hours (Figure 8)), compared to the lysine and silicate solution on the left where the solution is gelled after about 24 hours. In Figure 10, the lysine and silicate solution is shown to be gelled after about 24 hours (solution to the left) as compared to the same solution at the beginning of the treatment period (solution to the right). Figure 11 shows the visible gelation of the lysine silicate solution after about 24 hours.
All core chips appeared to be stable during the time frame of analysis and retained their structural integrity, as can be seen from the photos.
Date Recue/Date Received 2020-04-24 The above disclosure generally describes the present invention. Although specific terms have been employed herein, such terms are intended in a descriptive sense and not for purposes of limitation.
It will be understood that certain of the above-described structures, functions, and operations of the above-described embodiments are not necessary to practice the present invention and are included in the description simply for completeness of an exemplary embodiment or embodiments. Although specific embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto, and that the invention may be practiced otherwise than as specifically described without actually departing from the spirit and scope of the present invention as defined by the appended claims.

Date Recue/Date Received 2020-04-24

Claims (144)

We claim:

1. A composition comprising an alkali silicate and a biomolecule, wherein the biomolecule is capable of delaying gelation of the alkali silicate for a period of time when in an aqueous medium.

2. The composition of claim 1, wherein the delaying is related to the ratio of the biomolecule to the alkali silicate.

3. The composition of claim 1 or 2, wherein the delaying is related to the type of biomolecule in the composition.

4. The composition of any one of claims 1 to 3, wherein when the composition is in contact with a subterranean formation, gelation of the alkali silicate is delayed.

5. The composition of any one of claims 1 to 3, wherein when the composition is in contact with a subterranean formation, the composition begins to gel after a period time.

6. The composition of any one of claims 1 to 5, wherein the biomolecule is capable of producing an alkaline aqueous composition when in the aqueous medium to delay gelation of the alkali silicate.

7. The composition of any one of claims 1 to 6, wherein the composition has an alkaline pH.

8. The composition of claim 7, wherein the pH is about 8 to about 10.

9. The composition of claim 7 or 8, wherein the pH is about 8.5 to about 9.5.

10. The composition of any one of claims 1 to 9, wherein the biomolecule is present in an amount of about 1% w/w to about 25% w/w.

11. The composition of any one of claims 1 to 10, wherein the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations thereof.

12. The composition of any one of claims 1 to 10, wherein the biomolecule comprises an amino acid selected from the group consisting of leucine, isoleucine, valine, methionine, tryptophan, phenylalanine, threonine, arginine, lysine, histidine, alanine, glycine, proline, glutamic acid, aspartic acid, asparagine, cysteine, glutamine, tyrosine, serine and mixtures thereof.

13. The composition of any one of claims 1 to 10, wherein the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.

14. The composition of any one of claims 1 to 10, wherein the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

15. The composition of any one of claims 1 to 10, wherein the biomolecule is an amino acid selected from arginine, histidine, lysine or mixtures thereof.

16. The composition of any one of claims 1 to 10, wherein the biomolecule is L-lysine.

17. The composition of any one of claims 1 to 16, wherein the delay is a partial, substantial or complete delay of gelation.

18. The composition of any one of claim 1 to 17, wherein the period of time is from after about 1 hour to after about 24 hours.

19. The composition of any one of claims 1 to 17, wherein the period of time is after about 4 hours, or after about 6 hours, or after about 24 hours.

20. The composition of any one of claims 1 to 19, wherein the aqueous medium is selected from the group consisting of water, fresh water, distilled water, sea water, salt water, brine, mixtures of water and water soluble organic compounds, and mixtures thereof.

21. The composition of any one of claims 1 to 19, wherein the aqueous medium comprises water.

22. The composition of any one of claims 4 to 21, wherein the subterranean formation is selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.

23. The composition of claim 22, wherein the subterranean formation comprises shale and/or coal seams.

24. The composition of any one of claims 1 to 23, wherein the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.

25. A composition comprising an alkali silicate and an amino acid.

26. The composition of claim 25 comprising about 1 to about 40% w/w of the alkali silicate and about 1 to about 25% w/w of the amino acid.

27. The composition of claim 25 or 26, wherein the amino acid is basic, such as arginine, histidine, lysine, or mixtures thereof.

28. The composition of claim 25 or 26, wherein the amino acid is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

29. The composition of claim 25 or 26, wherein the amino acid is arginine, histidine, lysine or mixtures thereof.

30. The composition of claim 25 or 26, wherein the amino acid is L-lysine.

31. The composition of any one of claims 1 to 30, wherein the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.

32. The composition of any of claims 1 to 30, wherein the alkali silicate is potassium silicate.

33. The composition of any one of claims 1 to 32, wherein the composition further comprises an additive.

34. The composition of claim 33, wherein the additive is present in an amount of about 1%
w/w to about 20% w/w.

35. The composition of claim 33 or 34, wherein the additive is selected from the group consisting of a metallic salt and a surfactant.

36. The composition of claim 35, wherein the metallic salt comprises potassium chloride.

37. The composition of claim 35, wherein the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.

38. The composition of any one of claims 1 to 37, wherein the composition is an aqueous composition.

39. The composition of claim 38, wherein the aqueous composition is clear.

40. The composition of claim 38, wherein the aqueous composition is slightly opaque.

41. The composition of claim one of claims 38 to 40, wherein the aqueous composition is substantially free of particulate matter.

42. The composition of any one of claims 1 to 41 for treating a subterranean formation penetrated by a wellbore.

43. The composition of any one of claims 1 to 41 for delaying gelation of the alkali silicate in the aqueous medium.

44. Use of the composition of any one of claims 1 to 41 for treating a subterranean formation penetrated by a wellbore.

45. Use of the composition of any one of claims 1 to 41 for delaying gelation of the alkali silicate in the aqueous medium.

46. A method of treating a subterranean formation penetrated by a wellbore comprising injecting the composition of any one of claims 1 to 41 into the subterranean formation.

47. A method of treating a subterranean formation penetrated by a wellbore comprising:
providing an aqueous composition comprising an alkali silicate and a biomolecule;
introducing the aqueous composition into the subterranean formation through a wellbore;
and delaying gelation of the alkali silicate in the aqueous composition for a period of time.

48. The method of claim 45, wherein the delaying is related to the ratio of the biomolecule to the alkali silicate.

49. The method of claim 45 or 46, wherein the delaying is related to the type of biomolecule in the composition.

50. The method of any one of claims 45 to 47, wherein the biomolecule is present in an amount of about 1% w/w to about 25% w/w.

51. The method of any of claims 45 to 48, wherein the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations/mixtures thereof.

52. The method of any one of claims 45 to 48, wherein the biomolecule comprises an amino acid selected from the group consisting of leucine, isoleucine, valine, methionine, tryptophan, phenylalanine, threonine, arginine, lysine, histidine, alanine, glycine, proline, glutamic acid, aspartic acid, asparagine, cysteine, glutamine, tyrosine, serine and mixtures thereof.

53. The composition of claim 25 or 26, wherein the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.

54. The composition of claim 25 or 26, wherein the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

55. The composition of claim 25 or 26, wherein the biomolecule is an amino acid selected from arginine, histidine, lysine or mixtures thereof.

56. The composition of claim 25 or 26, wherein the biomolecule is L-lysine.

57. The method of any one of claims 47 to 56, wherein the period of time is about 1 hour to after about 24 hours.

58. The method of any one of claims 47 to 56, wherein the period of time is after about 4 hours, or after about 6 hours, or after about 24 hours.

59. The method of any one of claims 47 to 58, wherein the delaying is a partial, substantial or complete delayed gelation.

60. The method of any one of claims 47 to 59, further comprising passing the composition through the subterranean formation.

61. The method of claim 60, wherein the passing comprises using pores and/or cleats of the subterranean formation as passage conduits for the composition.

62. The method of any one of claims 47 to 61, wherein the introducing comprises injecting the aqueous composition into the subterranean formation.

63. The method of claim 62, wherein the injecting is based on the calculated volume of the void space volume of the subterranean formation.

64. The method of claim 563, wherein the void space volume comprises a coal seam and an inter-burden shale layer.

65. The method of any one of claims 47 to 64, further comprising depositing the aqueous composition into the subterranean formation.

66. The method of any one of claims 47 to 65, further comprising flushing the wellbore with a post-flush solution.

67. The method of claim 66, wherein the post flush solution comprises 3%
potassium chloride and optionally a surfactant.

68. The method of any one of claims 47 to 67, further comprising injecting a spacer fluid into the wellbore.

69. The method of claim 68, wherein the spacer fluid prevents gelation of the composition in a production zone of the subterranean formation.

70. The method of any one of claims 47 to 69, further comprising flushing the wellbore with a pre-flush solution.

71. The method of claim 70, wherein the pre-flush solution comprises 3%
potassium chloride.

72. The method of any one of claims 47 to 71, further comprising putting the wellbore in shut-in position for a period of time.

73. The method of claim72, wherein the period of time is about 1 hour to about 24 hours.

74. The method of any one of claims 47 to 73, further comprising controlling fines migration to the wellbore.

75. The method of claim 74, wherein the controlling comprises retarding movement of at least a portion of any fine particulate material moving to said wellbore from the formation through incorporation and/or adherence of the fines to the aqueous composition.

76. The method of any one of claims 47 to 75, further comprising stabilizing the subterranean formation.

77. The method of claim 76, wherein the stabilizing is related to the degree of penetration of the composition into the subterranean formation.

78. The method of claim 76 or 77, wherein the stabilizing is semi-permanent or permanent.

79. The method of any one of claims 47 to 78, wherein the delaying allows for penetration into, and/or stabilization of the subterranean formation.

80. The method of any one of claims 47 to 79, further comprising allowing the composition to gel in the subterranean formation.

81. The method of any one of claims 47 to 80, wherein the subterranean formation is selected from selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.

82. The method of claim 81, wherein the subterranean formation comprises shale and/or coal seams.

83. The method of any one of claims 47 to 82, wherein the composition further comprises an additive.

84. The method of claim 83, wherein the additive is present in an amount of about 1% w/w to about 20% w/w.

85. The method of claim 83 or 84, wherein the additive is selected from the group consisting of a metallic salt, a surfactant and a combination thereof.

86. The method of claim 85, wherein the metallic salt comprises potassium chloride.

87. The method of claim 85, wherein the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.

88. The method of any one of claims 47 to 87, wherein the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.

89. The method of any one of claims 47 to 88, wherein the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.

90. The method of any one of claims 47 to 89, wherein the aqueous composition is clear.

91. The method of any one of claims 47 to 89, wherein the aqueous composition is slightly opaque.

92. The method of any one of claims 47 to 91, wherein the aqueous composition is substantially free of particulate matter.

93. The method of any one of claims 47 to 92, wherein the aqueous composition has an alkaline pH.

94. The method of claim 93, wherein the aqueous composition has a pH of about 8 to about 10.

95. The method of claim 93 or 94, wherein the aqueous composition has a pH
of about 8.5 to about 9.5.

96. A method of making a composition, comprising added a biomolecule to an aqueous medium, mixing the aqueous medium to form an aqueous composition, and adding an alkali silicate to the aqueous composition.

97. The method of claim 96, wherein the mixing is continuous to form an aqueous solution of the aqueous composition.

98. The method of claim 96 or 97, wherein the aqueous composition is clear.

99. The method of claim 96 or 97, wherein the aqueous composition is slightly opaque.

100. The method of any one of claims 96 to 99, wherein the aqueous composition is substantially free of particulate matter.

101. The method of any one of claims 96 to 100, wherein the biomolecule is present in an amount of about 1% w/w to about 25% w/w.

102. The method of any one of claims 96 to 101, wherein the biomolecule is selected from the group consisting of amino acids, esters thereof, analogs thereof, oligomers thereof, peptides, polypeptides and combinations thereof.

103. The composition of claim 102, wherein the amino acid is basic, such as arginine, histidine, lysine, or mixtures thereof.

104. The composition of claim 102, wherein the amino acid is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

105. The composition of claim 102, wherein the amino acid is arginine, histidine, lysine or mixtures thereof.

106. The composition of claim 102, wherein the amino acid is L-lysine.

107. The method of any one of claims 96 to 106, wherein the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.

108. The method of any one of claims 96 to 107, wherein the alkali silicate is present in an amount of about 1% w/w to about 40% w/w.

109. The method of any one of claims 96 to 108, further comprising added an additive to the aqueous composition.

110. The method of claim 109, wherein the additive is present in an amount of about 1% w/w to about 20% w/w.

111. The method of claim 109 or 110, wherein the additive is selected from the group consisting of a metallic salt, a surfactant and a combination thereof.

112. The method of claim 111, wherein the metallic salt comprises potassium chloride.

113. The method of claim 111, wherein the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.

114. The method of any one of claims 96 to 113, wherein the aqueous composition has an alkaline pH.

115. The method of claim 114, wherein the pH is about 8 to about 10.

116. The method of claim 114 or 115, wherein the pH is about 8.5 to about 9.5.

117. A composition obtained by the method of any one of claims 96 to 116.

118. A composition comprising an alkali silicate and a biomolecule, wherein the biomolecule controls gelation time of the alkali silicate in an aqueous medium.

119. The composition of claim 118, wherein the biomolecule controls gelation time of the alkali silicate in the presence of a subterranean formation.

120. The composition of claim 118 or 119, wherein the biomolecule is an amino acid.

121. The composition of claim 118 or 119, wherein the biomolecule is a combination of amino acids selected to achieve a desired gelation time.

122. The composition of any one of claims 118 to 121, wherein the biomolecule is an amino acid that is basic, such as arginine, histidine, lysine, or mixtures thereof.

123. The composition of any one of claims 118 to 121, wherein the biomolecule is an amino acid that is charged, such as arginine, lysine, aspartic acid, glutamic acid, or mixtures thereof.

124. The composition of any one of claims 118 to 121, wherein the biomolecule is L-lysine.

125. The composition of any one of claims 118 to 124, wherein the alkali silicate is selected from the group consisting of lithium silicate, sodium silicate, potassium silicate, cesium silicate and mixtures thereof.

126. The composition of any of claims 118 to 125, wherein the alkali silicate is potassium silicate.

127. The composition of any one of claims 118 to 126, wherein the composition further comprises an additive.

128. The composition of claim 127, wherein the additive is present in an amount of about 1%
w/w to about 20% w/w.

129. The composition of claim 127 or 128, wherein the additive is selected from the group consisting of a metallic salt and a surfactant.

130. The composition of claim 129, wherein the metallic salt comprises potassium chloride.

131. The composition of claim 130, wherein the surfactant is selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a combination thereof.

132. The composition of any one of claims 118 to 131, wherein the composition is an aqueous composition.

133. The composition of claim 132, wherein the aqueous composition is clear.

134. The composition of claim 132, wherein the aqueous composition is slightly opaque.

135. The composition of claim one of claims 132 to 134, wherein the aqueous composition is substantially free of particulate matter.

136. The composition of any one of claims 132 to 135, wherein the aqueous composition has an alkaline pH.

137. The composition of claim 136, wherein the pH is about 8 to about 10.

138. The composition of claim 136 or 137, wherein the pH is about 8.5 to about 9.5.

139. The composition of any one of claims 119 to 138, wherein the subterranean formation is selected from selected from the group consisting of sandstone, limestone, dolomite, shale, coal seams, tar sand, unconsolidated formation and combinations thereof.

140. The method of claim 139, wherein the subterranean formation comprises shale and/or coal seams.

141. The composition of any one of claims 118 to 140 for delaying gelation of the alkali silicate in the aqueous medium.

142. Use of the composition of any one of claims 118 to 140 for treating a subterranean formation penetrated by a wellbore.

143. Use of the composition of any one of claims 118 to 140 for delaying gelation of the alkali silicate in the aqueous medium.

144. A method of treating a subterranean formation penetrated by a wellbore comprising injecting the composition of any one of claims 118 to 140 into the subterranean formation.