# Zero Discharge Water Management for Horizontal Shale Gas Well Development

Final Report

Start Date: October 1, 2009

End Date: March 31, 2012

Authors: Paul Ziemkiewicz, PhD Jennifer Hause Raymond Lovett, PhD David Locke Harry Johnso n Doug Patchen, PG

Report Date Issued: June 2012

DOE Award #: DE

- FE0001466

Submitting Organization: West Virginia Water Research Institute West Virginia University PO Box 6064 Morgantown, WV 26506

- 6064

FilterSure, Inc. PO Bo x 1277 McLean, VA 22101

ShipShaper, LLP PO Box 2 Morgantown, WV 265072 | P a g e



### Acknowledgment "This material is based upon work supported by the Department of Energy und er Award Number

DE

- FE0001466."



### Disclaimer "This report was prepared as an a ccount of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for th e accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade n ame, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily s tate or reflect those of the
United States Gove rnment or any agency thereof."



### Abstract Hydraulic fracturing technology ( fracking ), coupled with horizontal drilling, has facilitated exploitation of huge natural gas (gas) reserves in the Devonian

- age Marcel lus Shale Formation (Marcellus) of the Appalachian Basin. The most

- efficient technique for stimulating Marcellus gas production involves hydraulic fracturing (injection of a water

- based fluid and sand mixture) along a horizontal well bore to create a seri es of hydraulic fractures in the Marcellus. The hydraulic fractures free the shale

- trapped gas, allowing it to flow to the well bore where it is conveyed to pipelines for transport and distribution.

The hydraulic fracturing process has two significant effe ct s on the local environment . First

, water withdrawals from local sources compete with the water requirements of ecosystems, domestic and recreational users, and/or agricultural and industrial uses. Second , when the injection phase is over, 10 to 30% of t he injected water returns to the surface. This water consists of flowback, which occurs between the completion of fracturing and gas production, and produced water, which occurs during gas production. Collectively referred to as returned frac water (RFW) , it is highly saline with varying amounts of organic contamination. It can be disposed of, either by injection into an approved underground injection well, or treated to remove contaminants so that the water meets the requirements of either surface relea se or recycle use

. Depending on the characteristics of the RFW and the availability of satisfactory disposal alternatives, disposal can impose serious costs to the operator . In any case, large quantities of water must be transported to and from well locati ons, contributing to wear a nd tear on local roadways that we re not designed to handle the heavy loads and increased traffic. The search for a way to mitigate the situation and improve the overall efficiency of shale gas production suggested a treatment met hod th at would allow RFW to be used as make

- up water for successive3 | P a g e

fracs. RFW, however, contains dissolved salts, suspended sediment and oils that may interfere with fracking fluids and/or clog fracture s. This would lead to impaired well productivity. The major technical constraints to recycling RFW involves: identification of its composition, determination of industry standards for make

- up water, and development of techniques to treat RFW to acceptable levels. If large scale RFW recycling becomes feas ible, the industry will realize lower transportation and disposal costs, environmental conflicts, and risks of interruption in well development schedules.4 | P a g e



### Table of Contents Acknowledgment

................................ ................................ ................................ ............................ 2

Disclaimer

................................ ................................ ................................ ................................ ....... 2

Abstract

................................ ................................ ................................ ................................ ........... 2

Overview

................................ ................................ ................................ ................................ ......... 6
Project Structure

................................ ................................ ................................ .............................. 7

Phase I

................................ ................................ ................................ ................................ ......... 7
Recommendations of the Industry Contact Group

................................ ................................ .. 7

Table 1: Industry Contact Group Chemical Criteria for Frac Water Make

- up

............... 8

Phase II

................................ ................................ ................................ ................................ ........ 9

Phase I:

................................ ................................ ................................ ................................ ............ 9

Filtration with Pretreatment

................................ ................................ ................................ ............ 9

Dissolved Solids Removal

................................ ................................ ................................ .......... 9

Table 2: Costs of Various Treatment Methods

................................ .............................. 10
Figure 1 : Comparison of Cost and Efficiency for Nanofiltration and RO

...................... 11
Figure 2 : Comparison of Cost and Flow of Nanofiltration and RO

................................ 11
Figure 3 : Comparison of Cost and Electricity Cost of Nanofiltration and RO

............... 12

Table 3: Chemical Results of Raw Samples of RFW

................................ ................... 13

Salts Removal Research

................................ ................................ ................................ ............ 13

Table 4: Frac Water Treatment Usin g 44% 2

- propanol

................................ ................ 14

Table 5: Frac Water Evaluated w/ Ammonia (Bottle Method, mean of 3 trials)

.......... 15

Table 6: Frac Water Evaluated w/ 2

- propanol (Bottle Method, mean of 3 trials)

......... 1 6

Table 7: Frac Water Evaluated w/ 2

- propanol (Beaker Method, mean of 3 trials)

....... 17
Laboratory Verification of PDU

................................ ................................ ............................... 17
Figure 4 : Media Testing of PDU for Treating Marcellus RFW

................................ ...... 18

Table 8: Summary of PDU and Laboratory Test Data

................................ .................. 19
Figure 5 : PSD Before and After FilterSure Filtration of a RFW Sample

....................... 20
Figure 6 : Particle Size in Raw a nd EC

- Treated Marcellus RFW

................................ .... 21

Filtration without Pretreatment

................................ ................................ ................................ ..... 22
Figure 7 : Predicting Stabilized Frac Water TDS when Recycling RFW

.............. 24

Table 9: RFW Dilution Model

................................ ................................ ...................... 25

Phase II:

................................ ................................ ................................ ................................ ........ 25

Mobile Treatm ent Unit Design, Construction and Operations

................................ ..................... 25
Figure 8 : MTU General Arrangement

................................ ................................ ............. 265 | P a g e

Figure 9 : Mobile Treatment Unit Piping Sch ematic Diagram

................................ ........ 27
Figure 1 0 : Finished Exterior View of MTU

................................ ................................ ..... 27
Figure 1 1 : Completed Interior View of MTU

................................ ................................ ... 28
Figure 1 2 : Particle Size Distribution Results

................................ ................................ .... 29

Table 10: Filtration Results of Filtered RFW Samples

................................ .................... 30

Field Trials

................................ ................................ ................................ ................................ .... 30

Site 1: Utica Shale Site

................................ ................................ ................................ .......... 30
Figure 1 3 : On Location at Utica Shale Site in Ohio

................................ ......................... 31
Fig ure 1 4 : Oil/Polymer Mixture Treated by MTU

................................ ........................... 32
Figure 1 5 : MTU Control Panel

................................ ................................ ......................... 33
Figure 1 6 : Control Panel Close

- Up View

................................ ................................ ......... 33
Figure 1 7 : Pressure Drop Measurements of MTU in Operation

................................ ....... 34
Figure 1 8 : Day 1 t hrough Day 6 Filtration Rates and Pressures

................................ ....... 35
Figure 19 : Filtration Rate and Pressure, Days 1 through 9

................................ ............... 36

Lessons Learned from Site 1

................................ ................................ ................................ ..... 37

Site 2: Marcellus Shale Site

................................ ................................ ................................ ... 37
Figure 2 0 : Marcellus Shale Site, West Virginia

................................ ................................ 38
Figure 2 1 : Water Treated for Fracturing Stages

................................ ............................... 39
Figure 2 2 : Rate and Pressure Data during Water Treatment

................................ ............ 40
Figure 2 3 : Influent and Effluent PSD from West Virginia RFW

................................ ..... 41

Table 11: Marcellus Shale Site Water Chemistry

................................ ............................ 42

Less ons Learned

................................ ................................ ................................ ........................ 42
Project Summary

................................ ................................ ................................ ........................... 42

Table 12: RFW Chemical Analyses

................................ ................................ ................. 43
Acronyms, Abbreviations and Units of Measurement

................................ ................................ .. 456 | P a g e



### Overview Shale gas production depends on the creation of permeability within an otherwise nearly impermeable rock formation. Two technologies have been applied to produce natural gas from tight shale formations: directional/ horizontal drilling and hydraulic fracturing

. Hydraulic
frac turing (fracking) uses large volumes of water to create numerous channels within the shale formation. Sand, pumped with the water

, pro ps open the hydraulic fractures, thus providing multiple, permeable flow paths for the natural gas.

Terminology used throughout this report to describe various types of water used in the fracking

process includes : 1. Frac water

– fluid prepared to carry sa nd (prop p ant) down

- hole under high pressure to create fracs (fissures) in the shale formation ; 2. Flowback water

– water that returns to the well head in advance of gas production ; 3. Produced water

– water that returns to the well head with gas during productio n ; and

4. Return frac water (RFW)

– f lowback and produced water.

RFW is highly variable, changing from well to well and also as a function of time. Besides water and sand, f

rac water contains a number of chemical additives with the end purpose to
enhanc ed g as production. U nless saline RFW is used to make up the frac water, the frac water will have a low salinity. Flowback water contains a high proportion of the frac water. The salinity of produced water is substantially higher than flowback water, probabl y due to the longer
formation residence time in which the water comes into contact with the formation salts. The Marcellus is known to be desiccated. Otherwise, it would undergo plastic deformation rather than fracture under pressure. Exceptions might o ccur where the well bore encounters a non

target formation; but, most of the water that returns from the well is the original injected water, or frac water. Our use of the term RFW recognizes in actual operations, flowback and produced
waters are often mi xed or otherwise managed as a single commodity.

The hydraulic fracturing process has two significant effect s on the local environment. First

, water withdrawals from local sources compete with the water requirements of ecosystems,
domestic and recreational users, and/or agricultural and industrial uses. Second , when the injection phase is over, 10 to 30% of the injected water returns to the surface. This water consists of flowback, which occurs between the completion of fracturing and gas production, and produced water, which occurs during gas production. Collectively referred to as returned frac water (RFW), it is highly saline with varying amounts of organic contamination. It can be disposed of, either by injection into an approved underground injectio n well, or treated to remove contaminants so that the water meets the requirements of either surface release or recycle use

. Depending on the characteristics of the RFW and the availability of satisfactory disposal alternatives, disposal can impose serious costs to the operator . In any case, large quantities of water must be transported to and from well locations, contributing to wear and tear on local7 | P a g e

roadw ays that we re not designed to handle the heavy loads and increased traffic. The search for a
way to m itigate the situation and improve the overall efficiency of shale gas production suggested a treatment method th at would allow RFW to be used as make

- up water for successive fracs. RFW, however, contains dissolved salts, suspended sediment and oils that m ay interfere with fracking fluids and/or clog fractures. This would lead to impaired well productivity. The major technical constraints to recycling RFW involves: identification of its composition, determination of industry standards for make

- up water, a nd development of techniques to treat RFW to acceptable levels. If large scale RFW recycling becomes feasible, the industry will realize lower transportation and disposal costs, environmental conflicts, and risks of interruption in well development schedu les.

On October 1, 2009, the United States Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) awarded West Virginia University (WVU) a cost

- sharing contract to evaluate techniques to be used or adapted to treat RFW. The project res ulted from a DOE Funding Opportunity Announcement (FOA) to encourage research of methods to managing hydraulic fracturing water withdrawals and RFW from gas development in the Marcellus. Filtration was considered a critical step in treating RFW for recycl e. In developing the project for DOE, WVU partnered with FilterSure, Inc. a developer of a multi

- media filter. The project was designed to characterize RFW, identify industry standards for make

- up water , evaluate
treatment methods

, and determine if pairi ng a technology with filtration was necessary and economically feasible to treat RFW prior to recycling for subsequent fracking operations.



### Project Structure

Phase I
Phase I objectives included the determination of water quality requirements for frac water make

up by compiling information on hydraulic fracturing practices, shale gas production practices,
and associated problems in the Appalachian shale formations . This led to the development and adaptation of advanced water treatment and filtration technol ogies that would convert the RFW into a usable substitute of fresh water for hydraulic frac turing. A Technology Status Report was compiled and provided an overview of current industry practices and associated costs to treat and/or dispose of RFW

. The ana lysis indicated t reatment and reuse of RFW for another drilling operation was a promising water management option and focused the project on treatment toward that goal

.

Recommendations of the Industry Contact Group
An Industry Contact Group was identified and a detailed questi onnaire was sent to the members. Responses yielded valuable information regarding RFW volumes and criteria necessary for recycling. The Industry Contact Group provided access to well development sites, water samples for testing by t he FilterSure process demonstration unit ( PDU ) and invaluable advice8 | P a g e

regarding configuration of our field

- deployable technology to match the contingencies of field operations. Some key results from discussions with the Industry Contact Group included:

 sli ckwater hydraulic fracturing was confirmed as the dominant type of stimulation

treatment ;

 water deman d for most horizontal wells range from about 4 to 6 million gallons, with up to 10 stages, and as much as 250 tons of sand per stage;

 vertical well hydraul ic fracturing s are similar in size to a single horizontal well stage, 500,000+ gallons, usually in a single stage, with a total of 250 to 500 tons of sand;

 RFW is approximatel y 10

- 3 0% of the amount injected. Flow is greatest during the first few days of water flow back and greatly reduced after the first week to 10 days, with
initial flow back rates averaging 3,000 to 5,000 barrels per day (90 to 150 gallons per minute ( gpm) ) and declining to less than a barrel per day after 60 days ; and

 horizontal and ve rtical fracs are both successful but horizontal wells appear to provide
better economics.

Industry standards for acceptable recycle water quality standards continue d to evolve . The consensus from the Industry Contact Group concerning acceptable water qua lity for recycled

RFW indicated total suspended solids (TSS) below 20 microns along with a range of other parameters presented in Table 1 . The TSS criteria reflects concerns with sediment accumulating in pores and the well bore while the chemical water qu ality parameters are thought to play a role in interfering with the performance of the frac water or with scale formation.

Table 1: Industry Contact Group Chemical Criteria for Frac Water Make

- up

Chemical Parameter Maximum Value (mg/L)*

TDS 50,000

Har dness 26,000

HCO 3 300

SO 4 50
Cl 45,000

Na 36,000

Ca 8,000 Mg 1,200

K 1,000

Fe 10

Ba 10

Sr 10

Mn 10

* Requirements of Industry Contact Group Members9 | P a g e

Industry also required a treatment system with minimal operation al and maintenance needs and a small footprint with minimal mobilization and de

- mobilization requirements . Upon review of the laboratory tests results and multiple discussion sessions with Industry representatives, the project team determined that the multi

- media filtration system was a necessary step in any treatment scheme. Removal of dissolved solids was considered important but not critical since
most of the criteria in Table 1 could be achieved through dilution with fresh water make

- up. Nonetheless, the project proceeded with tw o salt removal approaches: electro

- coagulation and a novel process in the conceptual stage of development.

Industry Contact Group recommendations were critical in refining project objectives. The testing and review of various water treatment technologies during Phase I of the project allowed the WVU project team to identify two options with potential for on

- site treatment and recycling
of RFW:

1. Filtration to reduce suspended solids, and

2. Electro

- coagulation (EC) to determine whether or not it could signific antly reduce
dissolved salts.



### Phase II Phase II of this project consisted of the design, fabrication and field deployment of a mobile treatment unit (MTU). The objective was to demonstrate a practical technology for TSS removal under actual field operatin g conditions. A project goal was for the treatment system design to
meet the need s of industry while providing a level of environmental protection and adaptability for future water quality and quantity criteria. The successful development of a technology to treat and recycle RFW will advance shale gas development through improved economics and environmental impacts. Improved economics will be achieved by reducing the amount of trucking and disposal of RFW and costs associated with these activities. By re using the RFW for subsequent hydraulic fractures , the need for fresh water will be reduced. The better you treat the RFW, the higher the blend ratio with fresh water, the less dependence and strain on local water resources, and the less impact on local inf rastructu re and the surrounding environment.



### Phase I :

Filtration w ith Pretreatment Early in the project, it was decided to test if filtration, which removes suspended solids but few dissolved solids, would benefit by coupling with a process for removing sa lts

. Various processes
were examined that included reverse osmosis (RO) , nanofiltration, and electro

- coagulation (EC)

.



### Dissolved Solids Removal
A WVU

- developed computer program that calculates the unit costs of various treatment methods

was revised with th e addition of new treatment methods (such as nano filtration and EC) and10 | P a g e

updated costs. Table 2 shows costs per 1000 gallons for a number of treatment option s utilized to manage RFW , including EC. The EC method appeared to be competitively priced among th e various options.

Table 2 : Costs of Various Treatment Methods

Treatment Method $ per1000 gallons

Surface disposal $0.07

Deep injection well

- existing $0.66

Evap oration /infil tration pond w/ spray $0.99

Spray Irrigation $1.08

Microfiltration $1.36

Evaporative pond

- Lined

- Spray $1.97

Electro

- coagulation $2.00

Shallow injection/aquifer renewal $2.85

Evaporative pond/infiltration $2.98

Water hauling $4.82

Deep injection well

- new $5.64

Nanofiltration $6.15

Reverse Osmosis $6.94

Evaporative po nd

- Lined $27.56

Figures 1 through 3 detail some of the initial investigations comparing reverse osmosis and nanofiltration, the former removing all ions while the latter only remove d multi

- valent ions. These are two proposed technologies for total dis solved solids ( TDS ) reduction or removal. The graphs compare cost versus process efficiency, cost versus flow, and cost versus electricity cost.
In all instances

, nanofiltration was cheaper because of its lower pressure requirements. The rise
in cost at low efficiency for the first p lot is due to increasing reject disposal costs. Low flow also increases the cost due to the fixed costs associated with the system. The increase in cost due to electricity rates is almost linear.11 | P a g e

Figure 1 : Comparison of Co st and Efficiency for Nanofiltration and RO

Figure 2 : Comparison of Cost and Flow of Nanofiltration and RO12 | P a g e

Figure 3 : Comparison of Cost and Electricity Cost of Nanofiltration and RO

To accu rately characterize RFW, the project team analyzed a number of samples provided by the Industry Contact Group. The samples represented RFW from operating sites in New York, Pennsylvania and West Virginia. The samples were drawn from storage tanks or pits and
represent ed a mixture of flowback and produced water. Five samples from the Marcellus and one sample from the Utica shale were tested. Table 3 provides a summary of the chemistry of
six raw RFW samples used in this study.13 | P a g e

Table 3: Chemical Results of Raw Samples of RFW

RFW
#1 RFW
#2 RFW
#3 RFW
#4 RFW
#5 RFW
#6 pH 7.4 6 6.1 7.4 6.3 6.3 6.7
Cond uctivity 23655 16807 66300 190100 183000 13900

SO 4 99 71 28 n d 414 19

Fe 37 27 37 59 30 27

Ca 319 1749 1640 19487 12800 698 Mg 31 122 193 1257 1470 60

Na 3550 2863 8560 35500 33700 2060

K n d 57 243 479 444 4 3

Sr 0.011 0.011 301 3559 1440 51

Ba 27 0 175 1641 176 14
Cl 6575 7172 17100 112457 65000 4600

TSS 44 220 99 74 570 25

TDS 16559 11765 46410 133070 128100 9730
Hard ness 923 4870 4890 53836 38000 1990
Oil & Grease 5 49 5 33 nd nd

n d = not detected



### Salts Removal Research Removal of highly soluble ions is difficult. As mentioned, reverse osmosis and nano

- filtration are able to remove the ions at a high cost. Electro

- coagulation was found to be ineffective. Preliminary research to determine the tech nical feasibility of using methods of dielectric lowering to remove salts was conducted. Ideally, this method would be coupled with the FilterSure filtration system for solids removal.

Preliminary r esearch on methods for removal of salts using dielectric reduction with solvents and mixed solvent systems was conducted . The aqueous solubility for potassium chloride (KCl) was determined to be 34.5 gm/100 gm of water. Investigations of mixed solids beginning with the
use of 2

- propanol followed to evaluate so lubility and conductivity. The solubility of KCl in 2

- propanol/water mixtures showed that the initial 26% KCl by weight dropped to nearly 1% when
the solvent was 80% 2

- propanol by weight. The concentration, referenced to the original water,
decreased fro m 345,000 mg/L to approximately 40,000 mg/L . Removal of the precipitated salt followed by removal of the 2

- propanol resulted in an 88% reduction of salt.

Experiments with potassium sulfate (K 2 SO 4 ) showed 90% less solubility with 20% (w/w) 2

- propanol tha n pure water. Although the analyses were conducted at 22 o C, and not at 50 o C,

K 2 SO 4 would be more soluble at the higher temperature.14 | P a g e

Potassium sulfate was found to have a solubility of 11.17 g m K 2 SO 4 /100 g m of water using the method developed earlier. The literature solubility is 12 gm/100 gm. The solubility of K 2 SO 4 in
a 20:80 w/w 2

- propanol:water mixture was found to be 0.98 gm/100 gm solvent.

One hundred milliliters (mL) of hydraulic fracturing water was also treat ed with 2

- propanol, resulting i n a lowering of the conductivity by about half. The behavior was tracked using conductivity. Lower conductivity is a complex function of solution dielectric changes and salt loss. The solution was recovered through filtering after addition of 80 gm of 2

- pr opanol. The 2

- propanol was evaporated, regenerating an aqueous solution that had a conductivity of 97 micro

siemens per centimeter ( μ S/cm ) , 50.5% of the original value. Comparison of salt content of the original and final solutions showed 24% of the orig inal sodium (55,000 mg/L ) and 37% of the original chloride (100,000 mg/L ) were removed, yielding 41 ,800 mg/L sodium and 63,000 mg/L
chloride. The final adde d 2

- propanol, 80 gm, corresponded to a solution that wa s 44% 2

- propanol. When converted to molar c oncentration, 0.57M of sodium is removed and 1M of
chloride. Other ions must be inv olved in chloride removal, 1:1 m olar removal is expected for sodium chloride ( NaCl )

. The resultant solution was analyzed for the major ions, Table 4

, showing significant r eductions in the divalent cations calcium, strontium and barium.

Table 4 : Frac Water Treatment Using 44% 2

- propanol

Ion Original water, mg/L Treated water, mg/L Percent reduction

Ca 21200 423 98
Sr 2970 <0.011 ~100

Ba 1280 <0.012 ~100

Ammonia was c hosen to be the eventual agent due to its ease of removal from solution . Initial studies used a 25% (w/w) aqueous ammonia solution. A new method was developed to avoid dilution of the ammonia. The solubility was determined by evaporating the water from the sample then reconstituting it in the 25% ammonia. The method was tested using K 2 SO 4 and water. The solubility found using the new method was 11.88 gm K 2 SO 4 /100 gm water, which is in better agreement with the literature value than the original method. The solubility of K 2 SO 4 in
the 25% ammonia solution was determined to be 0.43 gm/100 gm solvent. A literature value is
0.22 gm/100 gm solvent with 25.2% ammonia at 20 o C.

The analytical results (measurements of solution concentrations of the recovered water) for

K 2 SO 4 solubility in ammonia showed sulfa te concentrations near 1200 mg/L . This value corresponds to about 0.22 gm/100 g m solvent (although the volume has changed due to ammonia evaporation). The analytical results are disquieting for potassiu m. The potassium concen tration should be near 1000 mg/L , but are reported to be around 1 mg/L . The lack of accuracy implicates all analyses. The solutions for K 2 SO 4 solubility, for example, should have sulfate15 | P a g e

concentrations near 65,000 mg/L and 61,000 mg/L was found. However, very little potassium
was found.

The method was applied to mine water and applied to a second hydraulic fracturing water sample. The mine water had a reduction of calcium from 800 mg/L to roughly 25 mg/L

. Sulfate, however, re mained roughly the same as in the original sample. This is inconsistent, since gypsum is the least soluble solid for calcium in the system. An analytical error is suspected, probably for calcium. Mine water has a lower TDS content than hydraulic fractur ing
water and the method will be less effective.

Using what is called the Bottle Method, where the water of concern is evaporated, reconstituted in the solvent of interest and filtered, hydraulic fracturing water was tested with 25% ammonia
and 2

- propa nol. In addition, the original method, the Beaker Method, where 2

- propanol is added to the solution, then evaporated, was used.

The hydraulic fracturing water had an initial pH of 6.6. After re

- dissolving the salt in ammonia solution, then driving off much of the ammonia, the pH was 8.2. The solution contained 680 mg/L ammonia nitrogen, 826 mg/ L ammonia, which indicates over 96% removal of ammonia. The conductivity increased from 13.9 μ S/cm 2 to 15 μ S/cm 2 , an increase of 7.9%. The increase
can be att ributed to ammonia.

Ion concentrations shown in Table 5 decreased substantially for the alkaline earth elements magnesium, calcium, strontium and barium (Mg, Ca, Sr, and Ba), by one third for sulfate (SO 4 ) and marginally for potassium (K) and chloride (Cl ). The total dissolved solids for the original hydraulic fracturing water was 9760 mg/L , which is rather low to expect substantial removal by solubility decrease. The solubility of pure K 2 SO 4 in 25% ammonia is 0.22 gm/100 gm solvent, roughly 2.2 gm

/L , fa r in exc ess of the 43 mg/L seen here.

Table 5 : Frac Water Evaluated w/ Ammonia (Bottle Method, mean of 3 trials)

Ion Original water, mg/L Treated water, mg/L Percent reduction

Ca 698 10.3 98.5
Sr 51 7.5 86

Ba 14 0.063 99.5 Mg 60 <0.5 >99
SO 4 19 11 .9 37

K 43 37.3 13
Cl 4600 4160 1016 | P a g e

The removal of alkaline earth ions is largely through precipitation of their hydroxides at the high pH of the initial ammonia solution. That solution was filtered, then the ammonia driven off for the final pH of 8.2. The hydroxide solubilities are Ba>Sr>Ca>Mg. The sulfate solubilities are Mg>Ca>Sr>Ba. The removal order in ammonia is Ba>Mg>Ca>Sr, with barium out of order. The very low barium value is likely due to some barium sulfate precipitation, making it less

c oncentrated than the strontium.

The Bottle M ethod using 2

- propanol, results tabulated in Table 6

, is more indicative of dielectric constant lowering. Barium and strontium, the least soluble sulfates, are decreased, while magnesium and calcium are bare ly removed. The sulfate decrease indicates removal by barium and strontium, although a mass balance does not provide enough sulfates to account for all the strontium. The chloride decrease cannot be balanced by the measured cations. Sodium may be
the ca tion associated with chloride. The hydraulic fracturing water contained 2060 mg/L sodium, but its removal was not measured in the treated samples. The conductivity decreased to
0.67 μ S/cm 2 , a 95% decrease. Roughly half the salt isolated from the hydraul ic fracturing water
dissolved in the 2

- propanol, whereas 84% dissolved in the 25% ammonia solvent.

Table 6 : Frac Water Evaluated w/ 2

- propanol (Bottle Method, mean of 3 trials)

Ion Original water, mg/L Treated water, mg/L Percent reduction

Ca 698 629 0.9
Sr 51 14.8 71

Ba 14 0.27 98 Mg 60 56 6.8
SO 4 19 5.54 71

K 43 4.9 89
Cl 4600 1117 76

The more practical Beaker Method was conducted using 2

- propanol. Two hundred grams of 2

- propanol were added to 100 grams of the hydraulic fracturing water. Th e 2

- propanol was evaporated and water recovered. Very little solid was generated and with the exception of barium, very little change in concentration for the ions were seen, as presented in Table 7 . The conductivity of the resultant solutions averaged 14 μ S/cm 2

.17 | P a g e

Table 7 : Frac Water Evaluated w/ 2

- propanol (Beaker Method, mean of 3 trials)

Ion Original water, mg/L Treated water, mg/L Percent reduction

Ca 698 801

- 15
Sr 51 54.5

- 7
Ba 14 1.0 93 Mg 60 69

- 14
SO 4 19 16.5 13

K 43 41.5 3
Cl 4600 4240 8

The Beaker Method has been shown to successfully remove salts from higher dissolved solids hydraulic fracturing waters, but this water was too dilute. The intent was to lower TDS to 50,000 mg/L . This water started at 10,000 mg/L TDS. Barium removal was consistent in all cases. The change in solvent polarity lowered the solubility, which is small even in water, and removed
barium as the sulfate. Other ions were not removed. Some ions show ed a negative removal.
The final volume in all three treatme nts was less than the starting volume, hence some ion s showed higher concentrations.



### Laboratory Verification of PDU Laboratory studies consisted of multiple filtration runs, with and without EC pretreatment, with the objectives to determine an acceptable combination of filter media and evaluate the impact of EC pretreatment on the filtrate. Actual Marcellus RFW samples were used for all tests.

The PDU consisted of the 2

- gpm FilterSure multiple module, multi

- media filtration unit as
shown in Figure 4 . Th e unit consisted of five sequential modules containing selected filter media. As configured here, the five modules are made up of two stacks, three in one stack and two in the other, all five operating sequentially. If the media are selected correctly, all five modules will load up with solids at the same rate, minimizing offline time for backwashing the modules. A rented laboratory

- scale EC unit was used to pretreat water samples.18 | P a g e

Figure 4 : Media Testing of PDU for Treating Marcellus RFW

Once analyses were conducted on the raw RFW samples, each sample was divided into three
sub

- samples, one to be treated with EC only, one to be treated with the FilterSure filtration system, and one to be treated by the combination of EC plus FilterSure filtration. All samples were analyzed for natural salt constituents, TDS, T SS, h ardness, pH, and particle size
distribution , both before and after each te st. Results of tests were summarized in Table 8

.
Results indicated significant reductions in divalent ion concentrat ions and TSS were reduced by up to 76% with retention of nearly 100% of particles larger than three microns. Therefore, the process design system proposed by the WVU project team and verified through analyses, consisting of the EC technology followed by t he FilterSure filtration system, showed the capability to lower water hardness, reduce heavy metals to environmentally safe concentrations,
and lower TDS values of RFW to be ready

- for

- use for the next hydraulic fracturing operation.19 | P a g e

Table 8 : Summary of PDU and Laboratory Test Data

A:
Raw A:

FS A:
EC * A:
EC+FS B:

Raw B:

FS B:
EC * B:
EC+FS C:

Raw C:

FS C:
EC * C:
EC+FS pH 7.4 7.7 7.4 7.9 5.3 6.3 5.7 6.0 5.5 5.0 5.9 5.5
Cond 66300 51000 61500 48800 183000 148000 182000 182000 194000 195000 326000 200000

SO 4 28 11 21 13 414 101 131 88 73

- - - Fe 32 15 0 0 6 8

- - 40 45

- - Ca 1610 1540 1870 1040 10600 7830 9160 8820 21000 19300 20400 14600 Mg 188 175 196 121 1200 786 978 933 2220 2270 2050 1120

Na 8530 7260 9050 4960 32800 19500 21800 22600 45400 344 00 42500 31100

K 243 297 213 207 444 996 434 347 701 601 535 595

Sr 280 249 334 214 1340 1090 1110 1250 2980 3120 3110 3090

Ba 172 165 128 71 201 93 142 120 1440 1520 1390 741
Cl 17100 13000 14800 12600 65000 51000 61800 62400 80400 95400 64400 89600

TSS 99 81 5010 66 570 187 1050 138 882 681 112 302

TDS 38700 28200 35000 26800 112000 81400 95600 96500 188000 187000 210000 166000
Hard

ness 4890 4650 5620 3960 38000 22000 28900 25200 63400 74100 66000 42200

O&G nd nd nd nd nd nd nd nd 13 nd nd nd

FS = FilterSure; EC = electro

- coagulation ; Cond = Conductivity *EC technology provider considers the EC values to be misleading since lab tests can yield values for dissolved solids that include suspended solids. Provider filters their water with a 10

- micro n absolute filter to remove suspended solids before analyzing for solutes.

Based on the laboratory studies and the p reliminary analysis of various treatment options

, taking
into account costs and their capabilities to potentially treat RFW , the WVU projec t team
determined to further evaluate the use of filtratio n coupled with EC. A conceptual process train

was developed to include the EC unit preceding the multiple module, multi

- media filtration unit provided by FilterSure

. The upstream component, the EC unit, would pretreat the RFW to enhance the filtration efficiency of the Fi l terSure system. The EC converts some of the dissolved solids to suspended solids, by chemical or electro

- chemical means. Early testing demonstrated the capability to remove up t o 99% suspended solids and reduced certain important dissolved solids; therefore, the need for subsequent processing to reduce TDS did not appear to be necessary based on industry experience with recycling of RFW at that time

.

The FilterSure filtration s ystem had proved itself under a number of water treatment scenarios; however, performance treating RFW and its unique water chemistry was unknown. Three samples of RFW obtained had TDS values ranging from 10,000 to upwards of 188,000 mg/L. Radioactivity was determined to be at or below background levels and total hardness ranged from 5,000 to nearly 64,000 mg/L. Particle Size Distribution (PSD) analyses were performed on the RFW samples prior to and after filtration, and before and after EC. Figure 5 sh ows PSD

re sults of a RFW sample. A second RFW sample was treated by the EC unit followed by the FilterSure filtration system. As shown in Figure 6 , this non

- optimized EC test verified that EC was effective in coagulating many small particles to create mu ch larger, easily filtered particles. All small particles, less than approximately 8

- microns, were converted to larger particles ranging20 | P a g e

from about 10

- to 200

- microns, making them relatively easy targets for removal by the FilterSure filtration system.

Figure 5 : PSD Before and After FilterSure Filtration of a RFW Sample21 | P a g e

Figure 6 : Particle Size in Raw and EC

- Treated Marcellus RFW22 | P a g e



### Filtration without Pretreatment
Members of the WVU project team met with members of the Industry Contact Group
and to ured active well development sites in Pennsylvania and West Virginia. T he

purpose of these meetings and site visits was to confirm current water management practices being implemented in the field and determine how this project might impact industry pract ices.

From the information obtained during the se meetings and site visits, it wa s clear that large Marcellus Shale operators were not chemically treating their RFW prior to recycling . If they were treating the RFW , the treatment choice was 20

- micron si zed bag
filters . Water t reatment options were expected to have minimal operation and maintenance requirements and consist of a small, modular footprint. The operators
indicated a desire for further dissolved metallic solids reduction and sulfates reduction ; however, the removal of barium and strontium was no longer considered critical. Some of the producers inject ed untreated RFW , ignoring ideal design criteria established by the hydraulic fracturing support companies.

As a result of this industry input, it became clear to the WVU project team

, major producers did

not want or need the addition of EC or chemical flocculation prior to filtration as part of their

RFW treatment system for recycling purposes . Although the companies indicated a desire for heavy metals removal, they were not interested in anything that might slow down or complica te fracking operations , including large equipment on their “always too small” well sites. Industry
demonstrated their primary needs were high

- rate filtration operations

, a minimum of 100 gpm
and preferably much higher , while achieving suspended solids removal down to 20 microns. A reduction in sulfates was also considered important because of its capacity to form scaling compounds when the RFW would be recycled for new fra cking operations . Additionally, the

treatment syste m would need minimal operator support and maintenance, occupy a small footprint, and be easily mobilized and de

- mobilized from site to site

.

At the same time these activities were ongoing , the WVU projec t team was investigating the requirements for a full

- scale EC unit to pair with the FilterSure system . It was becoming apparent that the EC unit would be more cumbersome than originally envisioned, require its own mobile trailer unit and large source of po wer, and would cost more to obtain and operate ; not entirely insurmountable problems but worth further investigation

.

The use of the multi

- media FilterSure filtration system without EC pretreatment would provide
better mobil ity requiring only one mobile trailer unit , lower capital and operating costs

, and flexibility to meet throughput needs while meeting industry water treatment requirements for recycling RFW

. Therefore, the WVU project t eam concluded :23 | P a g e

 FilterSure’s multiple module, multi

- media filtrati on uni t met industry needs and offered a desirable level of environmental protection, and

 EC treatment was not a viable industry option for mobile treatment of Marcellus RFW

, with on

- site re cycling as the end objective . Rather, EC was more suited for use at a stationary treatment facility where water would be brought to the facility for treatment. An EC unit that would be able to adequately hand le the throughput needs of i ndustry would require a much larger footprint and source of power, two characterist i cs that are
not conducive or available to a Marcellus well site environment.

The WVU project t eam briefed DOE on the two viable options to move the project forward into the design, construction and field deployment phase :

1. Construct the EC and FilterSur e mobile unit having a c ombined rated capacity of 30

- gpm with a provision for by

- passing the EC unit

. This configuration would require two mobile trailer units, one for the EC unit and its separate power generator and one for all other components. The 30

- gpm size w as determined to be the largest

- sized EC unit t o keep the footprint and power requirements manageable for on

- site applications

. However, industry throughput requirements would not be met, or 2. Construct a mobile unit using only the Filter Sure mu ltiple module, multi

- media filtration technology providing a throughput capacit y of 120

- gpm with the possibility to approach
150

- gpm , while meeting minimum RFW treatment requirements

. This configuration would require one mobile trailer unit for all compon ents and power supply would be provided by a generator packaged with the mobile unit

.

After further evaluation , along with input from the DOE, option t wo was subsequently approved. The design of the prototype Mobile Treatment Unit (MTU) would consist of two
FilterSure multi ple module, multi

- media filtration units to provide the throughput capacity and minimum treatment requirements needed by industry for on

- site treatment of RFW

.

Opting for filtration without EC or other chemical pretreatment was expect ed to result in little or
no reduction in dissolved solids. Because RFW typically consist of high concentration s of various natural salts, the question arose among some Marcellus operators if salt concentrations
could reach a level that would deem the cont inued use of recycled RFW as part of the make

- up of hydraulic fracturing water detrimental to well production. Analysis showed recycled RFW could be reused indefinitely. The process of combining fresh water with the saltier RFW
resulted in a predictable but quickly

- stabilized build

- up of salt concentration s in the hydraulic fracturing water with successive blending cycles of RFW and fresh water

.

For a given development region, the saltiness of water mixtures used for any subsequent hydraulic fracturing operation should quickly reach a maximum. This maximum value is a24 | P a g e

function of the amount of RFW available for blending and its initial salt concentrations. This stabilization, or maximum salt co ncentration, occurs by the 3 rd repeat cycle as shown in Figure 7
and Table 9 . The salt concentration is ap proximately the same for the 4 th hydraulic fracturing cycle as for the 3 rd cycle, and will remain constant for all subsequent hydraulic fracturing operations, assuming no effective changes in signific ant variable s from well to well

.

Figure 7 : Predicting Stabilized Frac Water TDS when Recycling RFW

Table 9 provides a snapshot of the spreadsheet developed to calculate major ions and TDS concentrations of RFW recycled for subsequent fracturing operations. These values are based on the percent RFW recycled and blended with make

- up water and initial water quality
characteristics of both the make

- up water and RFW. The user of Table 9 inputs the percent recycle rate along with initial water quality characteristics for the make

- up water and RFW. Results of chemical analyses of the make

- up water source and the RFW being used are entered into the spreadsheet. Values for TDS and the various ions listed are then calculated for each repeat cycle. For example, if the t ypical amount of RFW is 20 % of the total amount of frac water injected, and the TDS of the RFW is 108,665 mg/L, the stabilized salt concentration, TDS, for future hydraulic fracturing jobs will be approximately 27,366 mg/L

. Levels of the ions barium (Ba), strontium (Sr) and sulfate (SO 4 ) found in the RFW, may be limiting factors for how
much RFW can be blended with fresh make

- up water for subsequent fracturing operations.25 | P a g e

Table 9: RFW Dilution Model

Insert date in yellow cells only *From BJ Services F R and SI (Scaltrol 720)



### Phase II :

Mobile Treatment Unit Design, Construction and Operations With approval to move to the design and construction phase, t wo 60

- gpm FilterSure commercial filters were selected for installation in a standard shipping container 40 feet long by 8 feet wide by 8 feet in height , mounted on a mobile chassis. Dual filter system controls provide automatic operation, maintenance operation, and monitoring of both filtration units. The system functions are controlled by a programmable logic controller (PLC) located in the control panel shown in Figure 8 . The PLC interfaces with an operator interface Touchscreen (also referred to as an

HMI

– human machine interface), remote sensors and system devices. The HMI monitors and
controls norm al operation; system set

- up such as timing, backwash settings and alarm settings; status and alarm conditions; and manual maintenance control. An operations manual along with instructions, drawings and schematics were placed inside the MTU for operator re ference.

Designed to process up to 5,000 barrels/day, t he mobile treatment unit (MTU)

, Figure 8

, was customized for well

- site applications providing a small footprint with an external generator for

power (50 kVA) , easy movement between well pads, and quic k set up for subsequent hydraulic fracturing activities. Once set up at a well pad site, the MTU will operate automatically requiring routine maintenance between fracturing treatments.26 | P a g e

Figure 8 : MTU General Arrangement

The flow of RFW through the mob ile treatment unit is straightforward as detailed by the piping
schematic in Figure 9 . An in

- line strainer is used to remove sticks and other large items that may be present in the RFW . The strained RFW then flows through two non

- metallic centrifugal

pu mps. Flow meters are present prior to each f iltration unit and sampling por ts have been built into the treatment process prior to and after filtration. Each pump feeds one f ilter at a pressure of 80 pounds per square inch (psi) or less. The filter s are designed with a media configuration capable of removing particles larger than three microns, making the fil tered water suitable for recycling purposes . The filtered water exits the MTU and is ready for blending with fresh water
for the next hydraulic frac turing operation.

Backwashing of a filter is determined by monitoring the pressure across each of the media
modules and will occur on an as

- needed basis, typically no more than twice each day, taking approximately 10 minutes for each backwash cycle per fil tration unit (all five modules)

. Backwashing of the filtration units is staggered to maintain one filtration unit in operation at all
times. Each filter unit is constructed to allow for one or all media modules to be taken off

- line
and backwashed. Captu red solids are flushed using water stored in the backwash water tank (see Figures 8 and 9 ). These solids exit the MTU and are managed for disposal by the operator. The
backwashed filter is returned to operation and the second filter is then taken off

- li ne to be
backwashed. Backwash water is returned to the beginning of the treatment process and mixed with incoming RFW for treatment

. However, the piping configuration for entering and exiting the MTU allows for flexibility in managing the backwash water.27 | P a g e

Figure 9 : Mobile Treatment Unit Piping Schematic Diagram

Construction of the MTU began in the spring of 2011 and proceeded without major issues. Figure s 1 0 and Figure 1 1

, exterior and interior photographs respectively, show progress near
the end o f the construction phase

.

Figure 1 0 : Finished Exterior View of MTU28 | P a g e

Figure 1 1 : Completed Interior View of MTU

Selection of the final filter media to be used in the MTU was determined by additional laboratory testing using the FilterSure 2

- gpm PDU. Nearly 100 barrels of Marcellus shale RFW were provided by a local operator for the additional laboratory tests. The RFW contained solids ranging in size from less than 3 microns to over 100 microns. Under high rate conditions, the PDU operating at rate s up to 6

- gpm, the media selected for the PDU removed parti c les larger
than 3 microns as shown in Figure 1 2

.29 | P a g e

Figure 1 2 : Particle Size Distribution Results

Over the course of the laboratory testing phase, the 2

- gpm FilterSure PDU consistently remove d solids and reduced various ions such as chlorides, sulfates, sodium and barium as summarized in
Table 10

. Chemically, the filtered RFW met the current industry standards for continued use as frac water when blended with fresh water. Therefore, the medi a and sequence tested in the 2

- gpm PDU was duplicated for both FilterSure filtration units installed in the MTU. Designed to process 5,000 barrels/day, the MTU was prepared for field deployment and real

- time testing.30 | P a g e

Table 10 : Filtration Results of Fil tered RFW Samples

A:
Raw A:

FS B:
Raw B:

FS C:
Raw C:

FS D:
Raw D:

FS Av erage Change,
%

Cl 17100 13000 65000 51000 80400 95400 150000 106667

- 14

SO 4 28 11 414 101 73

- 0 0

- 69

Fe 32 15 6 8 40 45 64 66 0

Ca 1610 1540 10600 7830 21000 19300 21000 22183

- 8

Mg 188 175 1200 786 2220 2270 2120 2187

- 9

Na 8530 7260 32800 19500 45400 34400 42780 42780 20

K 243 297 444 996 701 601 1810 1875 34

Sr 280 249 1340 1090 2980 3120 5060 5267

- 5

Ba 172 165 201 93 1440 1520 2290 2397

- 12

pH 7.4 7.7 5.3 6.3 5.5 5.0

- - 4

Cond 66300 51000 183000 148000 194000 195000 197000 197167

- 10

TSS 99 81 570 187 882 681 484 313

- 36

TDS 38700 28200 11200 81400 188000 187000 187000 168667

- 16

Hardness 4890 4650 38000 22000 63400 74100 65900 69300

- 6

O&G nd nd nd nd 13 nd nd nd

Charge Balance,
%diff 0 14 13 6 38 3 25 11 14

nd = not detected



### Fiel d Trials
Two field trials were completed, both under a lease agreement with Chesapeake Energy (Chesapeake) . The first location was a Utica Shale site in Carrollton, Ohio. The se con d was a
Marcellus Shale site located near Wheeling, West Virginia.



### Site 1: Utica Shale Site FilterSure moved the MTU from the manufacturing location to the first drilling site located in Carroll County, Ohio. Storage containers were available on site to hold water prior to filtration and to provide storage after treatment prior to blending with fresh water for the next fracturing operation. At this particular site, storage containers were the preferred method of water storage31 | P a g e

instead of impoundments. C hesapeake positioned the MTU where untreated water from the yellow tanks shown in Figure 1 3 could be easily connected to the MTU. The filtered water was transferred to empty storage tanks located to the right of the MTU (not shown in this photograph). Fi ltered R FW was blended with fresh water and used in subsequent hydraulic fracturing operations.

Figure 1 3 : On Location at Utica Shale Site in Ohio

The MTU was on site in Carrollton, Ohio for eleven days, of which the unit was in “operational
mode” n ine days. Once the MTU was positioned by Chesapeake on the well pad, it was connected to the generator for power and connections were made to the water storage tanks supplying water to be treated and collecting water after treatment. Commands for the PLC were updated and initial testing of the system was conducted prior to start

- up to ensure the alarm system and automatic shutdown mode executed properly. Emergency and safety systems were in place and worked according to the operations manual

.

The Ohio s ite consisted of one well with 15 fracking stages . The company on site overseeing the fracturing operations performed two fracking stages per day. Water was collected from various Chesapeake development wells and trucked to the Ohio site to be treated by the MTU prior to blending with fresh water. These liquids ranged in quality from rain water to highly saline water

. Some of the liquids also contained oil s and polymer s collected from recently fracked oil wells. In addition, as a part of its water mana gement pl an, Chesapeake routinely removed rain water trapped behind an exte nsive dyke system constructed for secondary containment of water that may leak from storage operations. This water was pumped into the “ raw ” water storage tanks t o be t reated by the MTU for recycling as well (yel low tanks shown in Figure 1 3 )

. The quality of32 | P a g e

the water being processed through the MTU was unpredictable, it was a highly variable liquid that sometimes contained a significant quantity of oil and/or polymer , as seen in Figure 1 4

. Although t he oil and po lymer mixture was processed (removed) by the MTU, it was at a cost of higher pressure and a reduced throughput rate.

Figure 1 4 : Oil/Polymer Mixture Treated by MTU

At the Carrollton, Ohio site, t he MTU processed water for fracking at a rate of 122 gallons/min (about 4,000 barrels/day ). Pressure across the filter modules remained relatively low, averaging around 30 psi. Water leaving the MTU was clear in appearance and influent and effluent samples were collected and processed for laboratory analysis. However , these samples were not considered to adequately represent the entire 200,000 gallons of water treated at the Ohio site because of the variation in water brought in to the site. The water chemistry wa s fairly consistent with other hydraulic fracturing water samples taken during this p roject for analysis. Also, filtration did not significantly change the water chemist ry of the major ionic species.

The MTU is designed for automatic or manual operations. However, to meet Chesapeake’s site safety guidelines, an MTU operator was on site while the unit was in operation. The panel mounted on the wall shown in the background of Figure 1 5 , controls the MTU operations and
records all operational conditions. Figure 1 6 is a photograph of the Touchscreen or HMI showing Filter 1 operating at 41 gpm and Filter 2 operating at 43 gpm ; thus, the t otal flow through the MTU at the ti me of the photograph was 84 gpm , or 2,880 barrels/day (bpd).33 | P a g e

Figure 1 5 : MTU Control Panel

Figure 1 6 : Control Panel Close

- Up View

A pressure gauge records the press ure drop from the inlet to the outlet of each filter, Figure 1 7

. At the time of this photograph, Figure 1 7 , the pressure drop across Filter 1 was 64 psig and across Filter 2 was 68 psig . The pressure drop across each module monitors the performance of
the media contained in each filtration cell (build

- up of solids removed from the water) , is used to adjust backwash cycles as needed and to modify selection of media for future applications based on the quality of water being treated by the MTU

.34 | P a g e

Figure 1 7 : Pressure Drop Measurements of MTU in Operation

Initial operations showed a gradual decline in the throughput (filtration) rate and a gradual increase in pressure as the media collected solids and the system stabilized. Figure 1 8 plots the throughput rates and inlet pressures for the first six days of operation. On day one, t he MTU began processing water at a throughput rate of 122 gpm ( 4,183 bpd) and stabilized at a throughput rate of 104 gpm (3,566 bpd) by day five. Over this period, the pressure in creased
from an initial pressure of 30 p sig to 53 psig.35 | P a g e

Figure 1 8 : Day 1 through Day 6 Filtration Rates and Pressures

During day six of operations, processed water containing a high concentration of an oil and polymer mixture

, as shown previously in Fig ure 1 4 , was received and processed through the

MTU. The impact of the heavy solids and oil/polymer loading on pressure and filtration rate is
reflected in Figure 19 . Pressure increased 32 %, from 53 psig to 70 psig. At the same time, the
rate decreased 2 5%, from 104 gpm to 78 gpm . Most of the oil and polymer mixture was captured during the normal programmed backwash cycles ; however, s ome of this mixture was
retained on the filter media. By day eight, the backwash c ycle s had successfully remov ed the

rema ining mixture of oil and polymer with trapped solids on the filter media , increasi ng throughput from 78 gpm to 84 gpm while simult aneously lowering the pressure from 70 psig to 66 psig . The backwash cleaning process returned operating conditions to a 100 gpm throughput

rate at an inlet pressure of approximately 45 psig by the end of day nine

.36 | P a g e

Figure 19 : Filtration Rate and Pressure, Days 1 through 9

Backwash cycles were originally programmed to occur once every twelve hours of operation

. Each module i s backwashed individually for a period of two minutes, with a total backwash time lapse of ten minutes per filtration unit. Backwash cycles were set manually at the Carrollton,
Ohio site until the MTU operators learned to manage the sporadic availability o f RFW to process for recycling and system upsets caused by the unpredictable introduction of the oil and polym er mixture in the influent stream

. Visual observation of the backwash water verified solids were being removed by the media. This initial field operation validated the extensive laboratory testing of the 2

- gpm PDU conducted at West Virginia University (WVU). Media selected for
the 2

- gpm PDU were subjected to extended

- run tests, leading to the selection of the media that were subsequently loaded into the MTU. No technical issues were encountered scaling from the

2

- gpm PDU used in the WVU tests to the 120

- gpm MTU.

At the Carrollton, Ohio site, t rucks delivered water around the clock in preparation for the hydraulic fracturing operations

. In addi tion to the MTU treating the water being received on site,
a 10

- micron bag filtration system was also on site as a second treatment option. The flow of water was split and sent to the MTU or bag filters for treatment. However, within minutes of receiving the water containing the oil and polymer mixture, the bag filters plugged and had to be
taken off

- line in order for the filters to be replaced. Processing of the water was slowed, reduced throughput, but the MTU operations continued without interruption

, removing the oil/polymer mixture from the water and recapturing it through the backwash cycles.37 | P a g e

The MTU utilizing the FilterSure technology proved to be highly versatile responding to “ upset ” conditions. This response capability will continue to improve with future plan s to introduce an
additional media module that will capture oil

- based solutions before passing through to the other
media modules of the filtration unit

.



### Lessons Learned from Site 1 Laboratory tests using a consistent quality of produced water cannot match the variable quality and quantity of the water delivered to a site by hundreds of trucks supplying water from a wide variety of sources. Even so, laboratory tests conducted at WVU utilizing the 2

- gpm PDU for processing various RFW sampl es resulted in the selection of five media types that treated the water for recycling purposes.

Media for the MTU needs to be more robust in its capability to capture oil and/or polymers
before this m ixture enters the lower modules of the filter. In th e future, an oil

- loving media will be used to process the influent before i t enters the MTU or placed in the first of the five filtration modules used in the FilterSure technology. This approach will protect the lower modules from fouling, and greatly red uce the time to backwash the unit to restore overall throughput at a reasonable inlet pressure.



### Site 2: Marcellus Shale Site Upon completion of water treatment operations at the Carrollton, Ohio site , Chesapeake
relocated the MTU to a location ne ar Wheeli ng, West Virginia. Figure 2 0 shows the arrangement of water storage tanks and the MTU, the MTU is located in the left top corner of the photograph, on the well pad

. RFW for filtration was trucked onto the site and stored in the tanks in the foreground as shown in Figure 2 0

. From the storage tanks, the water was processed through the MTU. The filtered water was stored in the yellow tanks positioned to the right of the FilterSure unit and ready for blending with fresh water supplies prior to the hydraulic fracturing operations.38 | P a g e

Figure 2 0 : Marcellus Shale Site, West Virginia

Upon arrival at the new site , the Dytko Site, in West Virginia, a series of system checks were performed and the MTU was prepared to begin operations. The MTU supported a nine

- st age fracking operation, operating at an average filtration rate of 104 gpm and at a pressure of 52 psi g to treat RFW prior to blending with fresh water supplies

. Within four days, all stored RFW

, approximately 147,000 gallons, was filtered and consumed th e storage capacity provided for processed (treated) water ready for recycling

. Once fracturing operations began, the MTU was
taken off

- line during the actual fracture operations while water was withdrawn from the filtered
water tanks and blended with fres h water for use in fracturing. Filtration resumed after each fracture stage.

Figure 2 1 details the fracturing stages and the amount of RFW processed by the MTU. MTU

o perations were able to keep up with the ongoing demands to support the eight hydraulic
f racturing stages. One additional fracture was supported but not shown in Figure 2 1 before fracture operations were completed

. Nearly 288,000 gallons of water was processed by the MTU at the Dytko Site.39 | P a g e

Figure 2 1 : Water Treated for Fracturing Stages

Frequent rate and pressure dat a were taken during the fracking operations. Figure 2 2 summarizes this data showing stable throughput (filtration) rates and pressures. Filtration rate s averaged 104 gpm at an average filter inlet pressure of 52 psig. The re were no major deviations in the rate and pressure data, reflec ting relatively clean water was being processed for recycle

purposes

.40 | P a g e

F igure 2 2 : Rate and Pressure Data during Water Treatment

As mentioned previously, during active fracturing, the MT U was off

- line. While off

- line, captured solids were removed by backwashing each filter individually. Ten backwash cycles were completed using an average volume of 400 gallons per cycle. Backwash volume totaled 4,000 gallons. RFW p rocessed for recycle totaled 288 ,000 gallons for blending with fresh water

. Of the total volume of water sent through the MTU unit, 98.6% was recycled with 1.4% returned for disposal.

MTU operators learned from the Ohio site operations that water collected for physical and

c hemical analyses need to reflect a broad range of water influent and effluent. Accordingly, MTU operators collected composite samples over a period of time while at the Dytko Site

. These composite samples were submitted for particle size distribution (PS D) to the Civil Engineering Department at WVU and for chemical analysis by REIC Laboratories located in Beaver, West Virginia.

Concentration of particles in the collect ed water was un expected. All prior testing of Marcellus
Shale RFW had particle size distributions ranging from near

- zero to over 100 microns in size. However, both the influent and effluent water collected from the West Virginia site had particles that ranged from near

- zero to less than three microns. Concentration of the influen t and effluent particles is shown in Figure 2 3

.41 | P a g e

Figure 2 3 : Influent and Effluent PSD from West Virginia RFW

It is clear from Figure 2 3 , particle size data the MTU did indeed remove particles that were as
small as 0.5 microns in diameter. This is r emarkable removal efficiency and is shown graphically as the difference between the blue (influent) and the red (effluent) curves of Figure

2 3 . This reduction in volume shows up as a reduction in Total Suspended Solids (TSS) in the water chemistry analysi s prepared by REIC laboratories.

Water chemistry analysis results are presented in Table 11 . These results independently verify
the MTU removed 32% of the suspended solids. Specifically, the TSS fell from 360 mg/L to 244 mg/L, a reduction of 116 mg/L. Previous controlled laboratory testing using Marcellus Shale RFW samples had an average TSS influent of 517 mg/L and an average effluent of 316 mg/L; a reduction of 39%. The laboratory and the current TSS reductions from the West Virgini a site we re theref

ore similar.

TDS readings were very low, with the influent and effluent water at about 22,000 mg/L. Prior
Marcellus Shale RFW tested at WVU averaged 113,000 mg/L. Looking at the water chemistry of the RFW water received at the Dytko Site may have consi sted mostly of early flowback water42 | P a g e

(water returning back up hole in advance of gas production) and previously blended with fresh

water

. Comparing water quality parameters of the MTU influent and effluent to the values determined to be critical by the Ind ustry Contact Group detailed in Table 1 , both me t the criteria with the exception of iron, barium and strontium.

Table 11 : Marcellus Shale Site Water Chemistry

Avg Influent mg/L Avg Effluent

mg/L Avg Change

mg/L Avg Change,

%

Cl 15400 12300

- 3100

- 20

SO 4 24 24 0 0

TDS 21300 22600 1300 6

TSS 360 244

- 116

- 32

Ba 35 37 2 8

Ca 2660 2740 80 3

Fe 17 18 1 2
Mg 293 308 15 5

K 117 127 10 9

Na 5620 5830 210 4

Sr 360 364 4 1



### Lessons Learned Water collected for testing from the West Virginia site had v ery fine particles (less than 3 microns) and low TDS values ( average of 21,3 00 mg/L). Marcellus Shale water samples tested at the WVU laboratory during Phase I of the project as well as additional testing conducted at the beginning of Phase II to finalize filter media selections had significantly larger particles (over 100 microns) and a much higher TDS ( average of 113,000 mg/L). Although RFW treatment results met industry requirements for recycling, additional analyses of the influent and effluent

water stream may have been able to clarify the initial water quality results of the raw RFW received at the Dytko Site

.



### Project Summary Shale gas production depends on the creation of permeability within an otherwise nearly impermeable rock formation. Horizontal drilling and hydraulic fracturing have been applied to produce natural gas from tight shale formations previously thought to be non

- obtainable.43 | P a g e

Hydraulic fracturing (fracking) uses large volumes of water to create numerous channels within
the shale format ion. Sand, pumped with the water, props open the hydraulic fractures, thus providing multiple, permeable flow paths for the natural gas. However

, the withdrawal of local water resources for fracking and the returned frac water (RFW) create two significant environmental issues that must be dealt with. The search for a way to mitigate the situation and improve the overall efficiency of shale gas production suggested treatment of the RFW that would allow for the water to be recycled and reused for successive fracking operations. This would reduce the demand on local water resources and provide an economical and
environme ntally friendly way to manage the RFW. P roject objectives were to identify the composition of RFW, define industry standards for the quality o f make

- up water used for fracking

, and develop a technique to treat RFW for blending recycling.

Several samples of Marcellus Shale RFW were obtained and analyzed throughout the course of this project. Table 12 provides an overview of various chemical para meters acknowledging RFW is best characterized by providing a range of values for each. Differences in parameter values from sample to sample may be the result of 1) when the sample was taken during flow back, 2) the water quality characteristics of the o riginal frac water because sources of make

- up

water vary , 3) chemical additives blended with the frac water since each company has their own
mixture which is often proprietary, and/or 4) differences throughout the formation itself.

Table 12: RFW Chemical Analys es Raw RFW Samples Industry Guidelines

TDS 9730

– 188000 50000
Hardness 923

– 63400 26000

SO 4 nd

– 414 50
Cl 4600

– 80400 45000

Na 2060

– 45400 36000

Ca 319

– 21000 8000 Mg 31

– 2200 1200

K nd

– 701 1000

Fe 6

– 59 10

Ba 0

– 1640 10

Sr <1

– 3559 10
*Treated by FilterSure multiple module multi

- media filtration system

In dustry standard for acceptable RFW water quality standards continue to evolve. When contacted, t he consensus from the Industry Contact Group concerning acceptable water quality
f or recycled RFW indicated TSS values below 20 microns along with a range of other parameters also provided in Table 12 above. Concerns with sediment a ccumulations in the pores and well bore were reflected by industry’s TSS requirements. The other chemica l44 | P a g e

parameters were thought to interfere with the performance of the frac water and/or potentially
increase scale formation. Dissolved solids removal was important but not critical because most of the industry criteria could be achieve d with blending of the treated RFW and fresh water.

Based on industry input and preliminary analyses of RFW samples, the WVU project team proceeded to determine an efficient and effective method to treat RFW for recycling purposes. Filtration was determined to be a necessary treatment step, possibly coupled with a process for removing salts. Various processes were examine d such as reverse osmosis (RO), nano filtration
and electro

- coagulation (EC). Upon review of costs and operational requirements of the various processes, fur ther evaluation of EC was recommended.

Several RFW samples were obtained from various Industry Contact Group members. Samples were treated by a small

- scale EC unit and a 2

- gpm process demonstration unit (PDU) of the FilterSure multiple module, multi

- me dia filtration system

. Laboratory analyses showed that pretreatment of the water by EC prior to the FilterSure PDU filtration system was not required to
meet the water quality criteria of industry at that time for recycling RFW

. These results led to the design and construct ion of a mobile treatment u nit (MTU) utilizing the Filter Sure multiple module, muti

- media technology to field test

.

A fully

- automated MTU was designed, constructed and delivered to a Utica Shale site in
Carroll ton , Ohio during September 2011. The MTU consisted of two FilterSure filtration units each capable of operating between 60 and 70 gpm. Operations at the Utica Shale site were followed by operations at a Marcellus Shale site location near Wheeling, W est V irginia

. Capacity of the MTU was adequate to support field operations at both sites . The mobile unit was able to keep up with on

- going fracking operations and produce a quality efflue nt for blending
with fresh water and used for subsequent fracturing operations thus reducing the overall quantity
of fresh water needed for fracking operations and providing a cost

- effectiv e, environmentally

sound alternative for managing RFW . Over 600,000 gallons of water were treated at the two locations with 98.6% of the water being recycled. The remaining 1.4% was used to backwash the filtration units and then disposed of properly. Su spended solids were reduced by one

- third, particles as small as 0.5 microns were removed, and reduction in some divalent ion concentrations were observed during field testing . The MTU was able to handle water containing a highly

- viscous oil and polymer mi xture that was part of the RFW to be treated at the
Utica Shale site in Ohio

. Overall, t he MTU proved to be highly capable of responding to “ upset ”
conditions and treating RFW with wide ly variable concentration s of various chemical water quality parameters

.45 | P a g e



### Acronyms, Abbreviations and Units of Measurement

avg a verage

Ba Barium

bpd b arrels per day, barrels/day

Ca Calcium

Cl Chloride

cndctvty c onductivity

DOE Department of Energy

EC Electro

- coagulation

ECFS Electro

- coagulation and FilterSure

Fe Iron

FOA Funding Opportunity Announcement

gm g ram

gpm g allons per minute

HMI Human Interface Machine, Touchscreen

K Potassium

KCl Potassium Chloride

K 2 SO 4 Potassium Sulfate

kVA kilovolt ampere

Mg Magnesium

mg/L milligrams per liter

mL milliliters

MTU Mobile Treatment Unit

N a Sodium

NaCl Sodium Chloride

NETL National Energy Technology Laboratory

O&G Oil and Grease46 | P a g e

Pct Rtn percent ( % ) return

PDU Process Demonstration Unit

PSD Particle Size Distribution

psi pounds per square inch

psig pounds per square inch gauge

RFW Return Frac Water

RO Reverse Osmosis

SO 4 - 2 Sulfate

Sr Strontium

TDS Total Dissolved Solids

TSS Total Suspended Solids

WVU West Virginia University

w/ with

w/w wet weight

μM micro

- meter

μS/cm micro

- siemens per centimeter

μS/cm 2 micro

- siemens pe r square centimeter