Aenert news. Invention analysis
Previously, hydraulic fracturing technologies were briefly addressed in our related articles on unconventional gas (10.03.2021 and 17.03.2021) and Shale oil and gas (Energy, Gas & Water consumption on 29.11.2021 and Ecology & Environment on 04.02.2022).
Now we will revise one of the most important aspects of this field of technology – hydraulic fracturing proppants, their composition, production and use in fracking. For this purpose we have collected almost 6000 inventions published over the past 20 years and analyzed them using the Advanced Energy Technologies methodology.

The patents and patent applications under revision were published in 39 patent offices around the world by 1085 applicants from 39 countries.

Hydraulic fracturing proppants. Cumulative number of patents and applications*, relationship of number of applications to total number of documents by year

*Areas representing patents and applications are overlapping

In the pool of documents collected for this review, the peak values in the number of published patent applications can be seen in 2014-2019, which led to a growth in the number of granted patents in 2015-2020. The peak in the number of applications was followed by a small decline, so we can expect this trend to continue also for patents. Lately, the share of start documents that didn’t belong to any previously formed patent family was varying in the range of 31%-68%.

The number of newly appearing applicants in the collection of documents was on the rise in 2015-2018 with a moderate decline afterwards. Peak values in the newly appearing IPC indices were achieved in 2017-2020. New patent offices appeared in the selection of documents in 2002-2016. This may indicate that, although a small slowdown can be seen in the intellectual property activities in terms of geographical coverage and the number of new participants, the subject is expanding technologically, by steadily covering new areas.

In the revised pool of documents, the largest number of patents were issued during 20 years in the USPTO (US) patent office – 32% of all patents. CNIPA (CN) and CIPO (CA) followed the leader with almost 22% and more than 13%, respectively. Rospatent (RU), IP Australia (AU), and EPO should also be mentioned for having a considerable number of patents granted. In the collection of patent applications, CNIPA (CN) was in the lead with more than 35%. It was followed by USPTO (US) – almost 20%, and WIPO – more than 8% of applications.

Hydraulic fracturing proppants. Breakdown of inventions by patent offices. Patents, 20 years (left); Applications, 5 years (right)



Residents of the USA were in the lead by the number of patents granted during the 20-year period with a share of more than 61% of all cases. In the pool of patents, high activity was also shown by residents of China, Russia, Germany, and Canada. In the case of recent patent applications, the first place as well was taken by the residents of the USA with a share exceeding 53%, they were followed by the residents of China and Germany.

Below is a list of top 10 applicants having the highest Market involvement ratio for patents published in the 20-year period (Market involvement ratio = volume ratio multiplied by ownership ratio, where Volume ratio - share of applicant documents in total number of documents, Ownership ratio - applicant's participation share in total number of documents):

Hydraulic fracturing proppants. Top applicants by Market involvement ratio. Patents

In the collection of patents related to hydraulic fracturing proppants, the largest number of documents was issued to Halliburton Energy Services, Inc. (US), the company was granted 289 patents. It was followed by five applicants, each of which was granted more than 40 patents: Baker Hughes Incorporated (US), Carbo Ceramics, Inc. (US), BJ Services (US), Oren Technologies, LLC (US), and Oxane Materials, Inc. (US). In the collection of recent patent applications, the most active applicants were Halliburton Energy Services, Inc. (US) – 157 applications, Carbo Ceramics, Inc. (US) – 86 documents, Saudi Arabian Oil Company (SA) – 54, Dow Global Technologies, LLC (US) – 52 applications.

Hydraulic fracturing proppants. Top applicants by Market involvement ratio. Applications

The most commonly-encountered problems in the collection of patents and patent applications related to hydraulic fracturing proppants were: Low efficiency / Main processes, High OPEX / Operation and consumables, and Ecological balance. In the vast majority of cases, technical solutions disclosed in the patent documents under revision were represented in the form of methods and compositions. Devices were encountered substantially less often in the documents. The most popular IPC subgroups assigned to the patent documents were: C09K8/80 (Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open), E21B43/267 (reinforcing fractures by propping), E21B43/26 (by forming crevices or fractures), C09K8/62 (Compositions for forming crevices or fractures), and C09K8/68 (containing organic compounds).

The largest patent family in the pool of documents collected for the present analysis includes 39 patent documents and is represented by core document US20150011439A1 (Core document is a base document for which a complete description of the invention is available in generally-accessible patent databases). It is followed by patent families with core documents EP2937826A1 (30 patent documents) and WO2016193729A1 (28 documents):

THERMOSET NANOCOMPOSITE PARTICLES, PROCESSING FOR THIER PRODUCTION, AND THEIR USE IN OIL AND NATURAL GAS DRILLING APPLICATIONS / A: US20150011439A1 / IPC: C09K8/24, C09K8/80 / BICERANO Jozef / SUN DRILLING PRODUCTS CORPORATION / Appl. date: 24/09/2014; Publ. date: 08/01/2015 / United States Patent and Trademark Office / Core document: US20150011439A1 / Technology categories: HF / Technology elements: FPA / Problems: LEMP / Technical solution types: C / Claims: 4 / Rating: 8

SYSTEM OF DELIVERING AND STORING PROPPANT FOR USE AT A WELL SITE AND CONTAINER FOR SUCH PROPPANT / A: EP2937826A1 / IPC: G06Q10/06 / OREN JOHN / OREN JOHN / Appl. date: 18/03/2013; Publ. date: 28/10/2015 / European Patent Organisation / Core document: EP2937826A1 / Technology categories: HF / Technology elements: FPA / Problems: AOP, EB, HCEI, HCEP, HOOC / Technical solution types: D, M / Claims: 15 / Rating: 8

THERMALLY INDUCED LOW FLOW RATE FRACTURING / A: WO2016193729A1 / IPC: E21B43/26, E21B47/06 / SANTARELLI FREDERIC JOSEPH / GEOMEC ENGINEERING LTD / Appl. date: 02/06/2016; Publ. date: 08/12/2016 / World Intellectual Property Organization / Core document: WO2016193729A1 / Technology categories: DD, HF, TG, TO / Technology elements: FEM, FPA / Problems: EGWC, LEMP / Technical solution types: M / Claims: 25 / Rating: 6

The following abbreviations are used in the documents hereinbefore and hereinafter: C - Composition; D - Device; M - Method; HF - Hydraulic fracturing; DD - Directional drilling; TG - Tight gas / Shale gas; TO - Tight oil; AOP - Administrative and organisational problems; EB - Ecological balance; EGWC - Energy, gas or water consumption; HCEI - High CAPEX / Exploration and Infrastructure; HCEP - High CAPEX / Equipment production; HCG - High costs in general; HOOC - High OPEX / Operation and consumables; HORR - High OPEX / Repair and replacement; LEMP - Low efficiency / Main processes; DR - Drilling and well elements; FEM - Hydraulic fracturing equipment and methods; FO - Other equipment, methods and materials for fracking; FPA - Hydraulic fracturing materials / Propping agents; FWF - Hydraulic fracturing materials / Working fluids.

Hydraulic fracturing proppants. Breakdown of documents by family size. Patents and applications



Following are several examples of patent documents having the highest rating calculated using the Advanced Energy Technologies methodology, from the pool of documents related to hydraulic fracturing proppants and their production:
Hydraulic fracturing proppants. Prominent patent documents by rating:

METHODS OF STIMULATING A SUBTERRANEAN FORMATION COMPRISING MULTIPLE PRODUCTION INTERVALS / P: CA2589798C / IPC: E21B43/25 / EAST LOYD E JR, CAVENDER TRAVIS W, ATTAWAY DAVID J / HALLIBURTON ENERGY SERVICES, INC. / Appl. date: 18/10/2005; Publ. date: 08/06/2006 / Canadian Intellectual Property Office / Core document: RU2398959C2 / Technology categories: DD, HF / Technology elements: DR, FEM, FPA, FWF / Problems: HOOC, LEMP / Technical solution types: M / Claims: 59 / Rating: 22

A COMPOSITION AND METHOD FOR MAKING A PROPPANT / P: CA2659669C / IPC: B01J2/00, C04B14/02, C04B38/00, C09K8/80, E21B43/267 / SMITH RUSSELL J, LOSCUTOVA JOHN R, et al. / HALLIBURTON ENERGY SERVICES INC, OXANE MATERIALS INC / Appl. date: 09/07/2007; Publ. date: 02/05/2017 / Canadian Intellectual Property Office / Core document: US7867613B2 / Technology categories: HF / Technology elements: FPA / Problems: EB, EGWC, HOOC, LEMP / Technical solution types: C, M / Claims: 89 / Rating: 21

Degradable fiber systems for stimulation / P: US7833950B2 / IPC: C09K8/62, E21B43/16, B01F17/00 / Willberg Dean M, Fredd Christopher N, Bulova Marina / Schlumberger Technology Corporation / Appl. date: 30/05/2008; Publ. date: 16/11/2010 / United States Patent and Trademark Office / Core document: EA9171B1 / Technology categories: HF / Technology elements: FEM, FO, FPA / Problems: HCG, LEMP / Technical solution types: M / Claims: 19 / Rating: 21

Degradable fiber systems for stimulation / P: US7380601B2 / IPC: E21B43/22, E21B43/267, C09K8/70, C09K8/80 / Willberg Dean M, Fredd Christopher N, Bulova Marina / Schlumberger Technology Corporation / Appl. date: 28/08/2007; Publ. date: 03/06/2008 / United States Patent and Trademark Office / Core document: EA9171B1 / Technology categories: HF / Technology elements: FEM, FO, FPA / Problems: HCG, LEMP / Technical solution types: M / Claims: 25 / Rating: 21

METHODS OF CONSOLIDATING PROPPANT IN SUBTERRANEAN FRACTURES / P: CA2415814C1 / IPC: E21B43/267, C09K3/00, C09K8/62, C09K8/80, E21B43/02 / NGUYEN PHILIP D, BARTON JOHNNY A / HALLIBURTON ENERGY SERVICES, INC. / Appl. date: 07/01/2003; Publ. date: 21/03/2006 / Canadian Intellectual Property Office / Core document: US6668926B2 / Technology categories: HF / Technology elements: FPA / Problems: HOOC, HORR, LEMP / Technical solution types: C, M / Claims: 37 / Rating: 21

Method of treating subterranean formations using mixed density proppants or sequential proppant stages / P: US7918277B2 / IPC: E21B43/267 / Brannon Harold Dean, Wood William Dale, et al. / Baker Hughes Incorporated / Appl. date: 31/12/2008; Publ. date: 05/04/2011 / United States Patent and Trademark Office / Core document: US7918277B2 / Technology categories: HF / Technology elements: FEM, FPA / Problems: LEMP / Technical solution types: C, M / Claims: 70 / Rating: 21

Method of treating subterranean formations using sequential proppant stages / P: US8127850B2 / IPC: E21B43/267 / Brannon Harold Dean, Wood William Dale, et al. / Baker Hughes Incorporated / Appl. date: 04/04/2011; Publ. date: 06/03/2012 / United States Patent and Trademark Office / Core document: US7918277B2 / Technology categories: HF / Technology elements: FEM, FPA / Problems: LEMP / Technical solution types: C, M / Claims: 22 / Rating: 21

In the recent patents and patent applications related to hydraulic fracturing proppants, the most noticeable groups of documents were those aimed at solving the problems of Low efficiency / Main processes, High OPEX / Operation and consumables, and Ecological balance. Below we provide several examples of inventions that concern these groups of technical solutions:

- US10538696B2 - improved performance, lowered ecological impact and costs are provided by a proppant comprising a core substrate with compressive strength 3,000 psi - 20,000 psi; a light-weight substrate, such as glass micro-spheres; a filler material, such as diatomaceous earth; an adhesive; and a phenolic resin additive;

- US20190270931A1 - dust generation in proppant handling is lowered without impairing its flowability properties by a proppant comprising a particle with a coating formed from an aqueous composition comprising 2-65 wt. % of a surfactant, 1-35 wt. % of a polymer binder in a water insoluble emulsion polymer, and balance water;

- US10731074B2 - method of producing a surface modified proppant comprising adding a chemical coating, which is non-petroleum-based, glycerin-based, or propylene glycol-based; and mixing it with the proppant so that the coating is 0.05 to 0.20 wt. % of the proppant. The invention aims at lowering costs, reducing potential health and environmental risks, and improving performance by avoiding dust and fines formation;

- US20190284468A1 - a proppant comprising a coating of a hydrogel-forming polymer such as starch, polyacrylamide. The hydrogel-forming polymer is crosslinked with a covalent crosslinker, such as an epoxide, an anhydride, an aldehyde, or others. The hydrogel coating further comprises alcohol, such as ethylene glycol, propylene glycol, or others. The invention is aimed at improving well production efficiency, reducing production costs of the proppant, and avoiding health risks;

- US20220025250A1 - undesirable pollutants are lowered and improved operational characteristics are achieved by proppant particles coated with partially cured phenolic resin (such as novolac resin) and covered with non-ionic surfactant (such as polyethylene glycol oleate), the proposed particles have specific tackiness value and other parameters.


Low efficiency / Main processes

Patent US10538696B2 published by Southwestern Energy Company (US) proposes a proppant comprising a core substrate with compressive strength 3,000 psi - 20,000 psi, a light-weight substrate comprising composite particles (glass micro-spheres, diatomaceous earth, expanded perlite and/or zeolite); a filler material (diatomaceous earth, perlite flour, zeolite powder, etc.), an adhesive (resin or foam) binding the two substrates together, and a phenolic resin additive. The claims of the invention provide detailed specifications of preferred variants of the proppant, and methods for its production, for instance, comprising "…mixing the plurality of composite particles and filler material with an adhesive to produce a light-weight coating; providing a core substrate; heating the core substrate to 600° F.; mixing the heated core substrate with the light-weight coating; and curing the adhesive at 25020 F. for approximately 4 hours.".

The authors mention high cost of proppant in prior-art solutions, and point out the need in a proppant that effectively stimulates subterranean formations and have smaller environmental impact.

The patent is a part of a family comprising 12 patent documents published in the CA, WO, AU, EP, CN, BR, MX, HK, US, and RU patent offices in 2016-2020.



Image from: US10538696B2

2 - proppant; 4 - core substrate; 6 - light-weight substrate; 8 - composite particles; 10 - filler material; 12 - adhesive.

A proppant for use in hydraulic fracturing is proposed in patent application US20190270931A1 by Dow Global Technologies, LLC (US) and Rohm and Haas Company (US). The proppant comprises a particle with a coating formed from an aqueous composition comprising 2-65 wt. % of a surfactant, 1-35 wt. % of a polymer binder in a water insoluble emulsion polymer, and balance water. The polymer binder of the invention is provided in two options: an aqueous dispersion of particles made from 0.1-20 wt. % of a carboxylic acid monomer and 80-99.9 wt. % of another ethylenically unsaturated monomer; and 1-25 wt. % of "…ethylenically unsaturated carboxylic acid monomer stabilized with a polyvalent metal" and 75-99 wt. % of another ethylenically unsaturated monomer. The authors propose (meth)acrylic acid as the ethylenically unsaturated carboxylic acid monomer, zinc or calcium as the polyvalent metal, alkoxylate as the surfactant. The coating covers less than 50% of the particle and can further comprise an optical brightener and an anti-freeze solvent.

The authors state that the proppant of the invention limits the generation of dust from proppants, and with reference to prior-art solutions concerning this problem, mention that they may result in proppant’s flowability properties.

The application belongs to a family consisting of 22 patent documents published in CA, WO, AU, CN, US, EP, CL, MX, BR, RU, SA, UA, US, and MX in 2015-2022.



Image from: US20190270931A1


High OPEX / Operation and consumables

Patent US10731074B2 by Arr-Maz Products, L.P. (US) discloses a method of producing a surface modified proppant, comprising adding a chemical coating and mixing it with the proppant in a powered continuous mechanical blender, a powered batch mechanical blender, or a static mixer, or spraying it on the proppant so that the coating is 0.05 to 0.20 wt. % of the proppant. The coating is not a thermoset polymer, not an ionic polymer, not a thermoplastic elastomer, and not a hydrogel. The coating proposed by the authors is non-petroleum-based, glycerin-based, or propylene glycol-based. The method further comprises adding a second chemical coating and mixing it with the proppant.

With regard to the drawbacks of prior-art solutions, the authors mention that a proppant should be less expensive to produce, and avoid formation of fines and dust, which inhibit the flow of hydrocarbons, thus reducing the productivity of the well and pose potential health and environmental risks.

The patent belongs to a family consisting of 26 patent documents published in US, WO, CA, AR, AU, GB, CN, BR, RU, and SA between 2015 and 2022.



Image from: US10731074B2

Patent application US20190284468A1 filed by Self-Suspending Proppant LLC (US) discloses a proppant comprising a particle substrate and a coating of a hydrogel-forming polymer. The coating is selected so that during fluid transport the hydrodynamic volume of the proppant is increased, while premature release of the coating is prevented so that the proppant can be sent to a desired location. The hydrogel-forming polymer is selected from such substances as polyacrylamide, carboxymethyl cellulose, guar gum, and others. The authors propose preferred hydrogel coatings, such as starch, polyacrylamide, or a cationic/anionic polymer pair, where the cationic polymer can be, for instance, polydiallyldimethylammonium chloride (poly-(DADMAC)). Preferably, the film of hydrogel-forming polymer is crosslinked with a covalent crosslinker, such as an epoxide, an anhydride, an aldehyde, or others. The hydrogel coating further comprises ethylene glycol, propylene glycol, or another alcohol from the suggested list. The claims of the invention also provide the operational characteristics of the resulting proppant.

The authors state that the proppant of the invention is aimed at improving the productivity of the well, and avoiding health and safety risks, the authors also mention the cost of the prior-art solutions as one of their drawbacks.

The application belongs to a patent family comprising 23 documents published in the CA, WO, US, AU, CN, EP, MX, RU, and BR patent offices in 2013-2020.



Image from: US20190284468A1


Ecological balance

Patent application US20220025250A1 by Durez Corporation published on 27.01.2022 discloses curable proppant particles and a method for their production and use in subterranean operations. The authors propose partially cured phenolic resin coated proppant particles comprising non-ionic surfactant (0.3%-2% of weight). The particles (sand, ceramic, glass spheres, or others) are covered with a single or double coat of partially cured phenolic resin (novolac resin, resole resin, or their combination), the outer coat being partially cured and having the non-ionic surfactant on top. The surfactant is having a hydrophilic hydrophobic balance in the range of 13 to 20 and is selected from polyethylene glycol oleate, polyethylene glycol monostearate, and others. The process for the production of the proppant includes heating the particles, adding a phenolic resin coat, adding a curative, partially curing, adding the non-ionic surfactant. The resulting particles are dry and free flowing at room temperature, are curable at a temperature below 180°F, and have a tackiness of less than 13.8 kPa (2 psi) in dry condition and 0.138 MPa - 0.965 MPa (20 to 140 psi) in wet condition. The claims of the invention include additional specific characteristics of the proposed proppant particles.

The authors mention that the proposed proppant provides environmental advantages by lowering undesirable pollutants, reduces the sand produced from the well, and exhibits good crush resistance.

The application belongs to a family comprising 17 patent documents published between 2016 and 2022 in US, WO, CA, AR, AU, MX, CN, EP, BR, and RU.



Image from: US20220025250A1

1 - particle; 2 - particle core; 3 - inner layer; 4 - outer layer.

During the analysis of these and other documents in the collection, it was revealed that there are groups of inventions, where the authors propose to combine the patented hydraulic fracturing proppants with specific fracturing fluids, or where the proppants are described along with preferred methods for conducting hydraulic fracturing. Smaller, but still noticeable groups of documents, besides proposing fracking proppants, also concern drilling processes and equipment, or other related equipment, methods and materials for fracking.

More detailed information about inventions in the field of hydraulic fracturing technologies, and patent research methodology can be found on aenert.com, and in OIL&GAS FROM LOW PERMEABILITY PLAYS. Hydraulic Fracturing Proppants. Patent Database. May 2021.

By the Editorial Board