METHODS AND SYSTEMS TO RAPIDLY HYDRATE DRY POLYACRYLAMIDES POLYMERS IN A CHEMICAL DELIVERY MATRIX

Abstract

A composition comprising a water-soluble powder that is agglomerated by a water-soluble wax, which is then allowed to cool and re-solidify to product clusters of the water-soluble powder.

Claims

1. A dry polyacrylamide, polyethylene oxide or natural polymer configured to be used in fracturing, as a dry friction reducer comprising: a dry polymer that is configured to be ground into fine particles to increase the exposed surface area of the dry polymer, wherein at least ninety percent of the fine particles of the dry polymer have a diameter smaller than 500 microns; a water-soluble wax that is configured to agglomerate the fine particles into larger prills or flakes.

2. The dry friction reducer of claim 1, wherein the water-soluble wax is configured to be heated into a molten state before or while mixing with the fine particles of the dry polymer.

3. The dry friction reducer of claim 2, wherein the mixed, heated water-soluble wax and fine particles of the dry polymer are cooled at a temperature less than a melting temperature of the water-soluble wax.

4. The dry friction reducer of claim 3, wherein a percentage of the fine particles of the dry polymer of a weight of the larger prills or flakes is between 50 and 95 percent.

5. The dry friction reducer of claim 1, wherein the dry polymer is one of a dry polyacrylamide powder, a dry polyethylene oxide powder, a dry bio polymer powder, a mixture of PAM, PEO or Biopolymer.

6. The dry friction reducer of claim 5, wherein the water-soluble wax is formed of at least one of polyethylene glycol, polypropylene glycol, polyvinyl alcohol, a polyol EO/PO block polymer, a waxy surfactant, such as an alcohol ethoxylate, nonylphenol ethoxylate.

7. The dry friction reducer of claim 1, further comprising: an accelerant that is added to the larger prills or flakes, wherein the accelerant is a surfactant, wicking agent, or effervescent.

8. The dry friction reducer of claim 7, wherein a dry exothermic salt is added to the larger prills or flakes to generate heat on contact with water.

9. The dry friction reducer of claim 7, wherein the accelerant is configured to release carbon dioxide when exposed to water to assist in dispersing the fine particles of the dry polymers from the water-soluble wax,

10. The dry friction reducer of claim 7, wherein the accelerant is added to a molten mixture of the water-soluble wax and the fine particles of the dry polymers.

11. A method of creating a dry friction reducer to reduce friction between fluid and pipes to while the fluid is being pumped downhole, the method comprising: grinding a dry polymer into fine particles to increase the exposed surface area of the dry polymer, wherein at least ninety percent of the fine particles of the dry polymer have a diameter smaller than 200 microns, wherein the dry polymer is a dry polyacrylamide powder; agglomerating the fine particles utilizing a water-soluble wax into larger prills; heating the water-soluble wax into a molten state before blending the fine particles of the dry polymer with the water-soluble wax. blending the heated water-soluble wax with the fine particles of the dry polymer to evenly disperse the water-soluble was and the fine dry polymer to form the larger prills that have a diameter larger than 2 mm, wherein a first percentage of a weight of the larger prills formed by the fine particles of the dry polymer of is between 50 and 95 percent and a second percentage of the weight formed by the heated water-soluble wax of the larger prills is between 10 and 25 percent.

12. (canceled)

13. The method of claim 11, further comprising: cooling the mixed, heated water-soluable wax and fine particles at a temperature less than one hundred fifty degrees Ferinheight.

14. (canceled)

15. (canceled)

16. The method of claim 11, wherein the water-soluble wax is formed of at least one of polyethylene glycol, polypropylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, a polyol EO/PO block polymer, a waxy surfactant, such as an alcohol ethoxylate, nonylphenol ethoxylate.

17. The method of claim 11, further comprising: adding an accelerant to the larger prills.

18. The method of claim 17, further comprising: releasing carbon dioxide via the accelerant when exposed to water to assist in dispersing the fine particles of the dry polymers from the water-soluble wax, wherein the larger prills are hydrated within fifteen seconds after being exposed to fluid.

19. The method of claim 17, wherein the accelerant is a surfactant, a wicking agent, or an effervescent.

20. The method of claim 17, further comprising: adding the accelerant to a molten mixture of the water-soluble wax and the fine particles of the dry polymers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following FIGURES, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0029] FIG. 1 depicts a method of making a dry friction reducer, according to an embodiment.

[0030] Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the FIGURES are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the FIGURES may be exaggerated relative to other elements to help improve understanding of various embodiments of the present disclosure. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure.

DETAILED DESCRIPTION

[0031] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. It will be apparent, however, to one having ordinary skill in the art, that the specific detail need not be employed to practice the present embodiments. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present embodiments.

[0032] In embodiments, an ultra-fine dry polyacrylamide friction reducer may be created to reduce friction in a casing. Utilizing a dry polyacrylamide friction reducer may save handling and logistical costs by reducing a total volume and weight of the product required to reduce friction downhole. Embodiments may be beneficial when the fracturing fluid is in the tubular members, such as pipes. Embodiments may be configured to agglomerate ground polyacrylamide with a water soluble wax to build larger particles out of the finely ground polyacrylamide, which can be more easily handled and flow more efficiently within the wellbore.

[0033] Embodiments of a friction reducer may include a dry polymer, water-soluble wax, and accelerant.

[0034] The dry polymer may be a dry polyacrylamide powder that is ground into fine particles to increase the exposed surface area of the dry polymer. The dry polymer may be configured to hydrate very quickly while being pumped downhole or immediately before being pumped downhole. For example, the dry polymer may be required to be hydrated within fifteen to sixty seconds after being exposed to fluid. This may require the dry polymer to be ground to very fine particles, wherein at least ninety percent of the particles of the dry polymer may have a diameter of no more than 150-200 microns. However, when the fine dry polymer is isolated from other products may cause fisheyes, dust, and/or allow the dry polymer to hydrate with humidity.

[0035] The water-soluble wax may be configured to agglomerate the fine dry polymer into more easily handled prills. The water soluble wax may be formed of: polyethylene glycol, polypropylene glycol, polyvinyl alcohol, a polyol EO/PO block polymer, a waxy surfactant, such as an alcohol ethoxylate, nonylphenol ethoxylate and/or a combination of water-soluble waxes. In embodiments, the wax may be configured to be melted, fed into a mixer or blender with the fine dry polymer to evenly disperse the water-soluble wax and fine dry polymer, to agglomerate the fine polymers together to form larger pills. This may create an agglomerated mixture that may be larger than 2 mm as a prill, which still hydrates quickly. Furthermore, the water-soluble wax may be configured to provide a water-soluble coating that provides a time release based on the solubility of the coating such that the dry polymers may be mixed in much higher concentrations before introducing the agglomerated mixture with fluids, and travelling downhole.

[0036] More specifically, conventionally only a single percent of dry polymer could be utilized because it is too viscous to pump once mixed. However, adding more of the water-soluble wax allows more handling time, such that ten to twenty percent of dry polymer may be utilized and pumped into the fracturing process before becoming too viscous to pump. Yet, when coating the fine dry polymer with the water-soluble wax, the agglomerated mixture may hydrate at less than desirable rates.

[0037] As such, an accelerant may be combined with the agglomerated mixture to act as a catalyst to speed up the rate of hydration of the agglomerated mixture. The accelerant may be a wicking agent, salt, citric acid and baking soda, and/or effervescent that is configured to rapidly hydrate the dry polymer and the water soluble wax when exposed to fluid. Specifically, the accelerant may be configured to release carbon dioxide when exposed to water, to assist in dispersing the fine dry polymer from the water-soluble wax within the agglomerated mixture, to break up the prill and hydrate the polymer quicker. In embodiments, the accelerant may be a wicking agent configured to interface water to the dry polymer within the agglomerated mixture quicker. The wicking agents may be mixed with water-soluble wax. There are more sophisticated wicking agents available and specifically meant to function to quickly wick water into the agglomerated prill to release the active polymer. Surfactants can also be mixed with the agglomerating wax to speed water-wetting of the polymer and to help disperse the dry polymer prills into water. Alternatively, or in addition to wicking agents, effervescent chemistry can be mixed into the dry polymer to enhance the release of the finely ground powder.

[0038] FIG. 1 depicts a method 100 for creating a dry friction reducer for use in a wellbore, according to an embodiment. The operations of method 100 presented below are intended to be illustrative. In some embodiments, method 100 may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of method 100 are illustrated in FIG. 1 and described below is not intended to be limiting.

[0039] At operation 110, a dry polymer may be grinded to create a fine dry polymer. In embodiments, the dry polymer may be grinded to approximately one hundred fifty microns.

[0040] At operation 120, a water soluble wax may be heated to a molten state. In embodiments, the water-soluble wax may melt between one hundred forty five and one hundred sixty degrees Fahrenheit.

[0041] At operation 130, the fine dry polymer and the molten, water soluble wax may be positioned within a mixer, such as a ribbon mixer. In embodiments, the molten, water-soluble wax may be inserted into the mixer. However, in other embodiments, the water soluble wax and the fine dry polymer may be mixed together within a plow mixer, and utilizing frictional heat cause the water-soluble wax to change from a solid state to a molten state within the mixer.

[0042] At operation 140, the fine dry polymer and the molten, water soluble wax may be combined together to form an agglomerated mixture. In embodiments, the percentage of the water soluble wax to fine dry polymer in volume within the agglomerated mixture may be between ten to twenty five percent.

[0043] At operation 150. The agglomerated mixture may be cooled to solidify the wax within the mixture, wherein the agglomerated mixture may be cooled to any level less than the molten state of water-soluble wax (i.e. one hundred forty five degrees Fahrenheit), such as one hundred fifteen degrees Fahrenheit.

[0044] At operation 160, an accelerating agent may be added to the cooled, agglomerated mixture. The accelerating agent may be any mechanism configured to allow the fine dry polymer within the agglomerated mixture disperse and hydrate quicker. In implementations, effervescence from the accelerating agent may form from gas generated by the reaction of an acid with a base. In most applications, effervescence that generates carbon dioxide is ideal. Sodium carbonate, potassium carbonate, etc. reacts with an inorganic dry acid such as sulfamic or an organic dry acid such as citric or tartaric acid to generate carbon dioxide and a salt. Those skilled in the art will realize you need the correct molar ratio of the base to the acid to complete the reaction and generate the most effervescence. There are also numerous combinations that will work, and different combinations maybe preferred for different applications. For example, some effervescence reactions generate oxygen that is not ideal for the fracturing process, but maybe beneficial for flocculation applications.

[0045] This may lead to a prilled friction reducer with a 70% ground polyacrylamide, 2% surfactant, and 28% polyethylene glycol 8000. Embodiments may be utilized in any application where it is desirable for effectively and efficiently handling dry polyacrylamide that hydrates quickly, such as reducing friction or water treatment.

[0046] Reference throughout this specification to “one embodiment”, “an embodiment”, “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, “one example” or “an example” in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures or characteristics may be combined in any suitable combinations and/or sub-combinations in one or more embodiments or examples. In addition, it is appreciated that the FIGURES provided herewith are for explanation purposes to persons ordinarily skilled in the art and that the drawings are not necessarily drawn to scale.

[0047] Although the present technology has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred implementations, it is to be understood that such detail is solely for that purpose and that the technology is not limited to the disclosed implementations, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present technology contemplates that, to the extent possible, one or more features of any implementation can be combined with one or more features of any other implementation.