Environmentally Focused Technologies for Oilfield Water

Treatment

Carl Vavra Global Petroleum Research Institute Texas A&M University Frank Platt Global Petroleum Research Institute Texas A&M University Rich Haut Houston Advanced Research Center—HARC

Summary of A&M Programs • EFD Program – an award winning program focused on

reducing environmental footprint associated with oil and gas operations. Produced water and frac flowback brine emphasized

• Technology Integration Program– an $ 8 million program designed to bring new technology to field trials – gas shales

• Advanced Analytics Program – new $ 3 million program designed to identify and field trial advanced analytic methodology for emissions and brine monitoring

Objectives of EFD Technology Integration Program

Speed the commercial development of technology developed through:

Research Partnership to Secure Energy for America (RPSEA) programs. 1. Create an organizational structure that includes a network of regional centers that facilitate and coordinate field deployment of such technologies and document effectiveness of field operations.

2. Perform field trials so that results could be evaluated efficiently as to benefit both the industry, the organizations with the technology, and the public sector.

3. Document and provide the results of technology field trials so that promising processes, systems and products could be utilized in a wider range of unconventional natural gas plays.

4. Emphasize programs that reduce cost and improve performance, lessen the environmental impacts, or address the societal issues associated with unconventional natural gas development.

5. Include and report on safety improvements in the planning/demonstration of technologies, emphasizing technologies that foster a culture of health/safety/environmental protection.

Monahan, TX Washington, PA

Footprint Reduction

Well Site Access & Drilling

Source: William Harrison, Kansas Geological Survey

Devon’s Barnett Shale “Pod” drilling (14 acres – 35 wells)

CROSS-FLOW FILTRATION CROSS-FLOW FILTRATION

CONTINUOUS OPERATION

Courtesy of NALCO

Water

Identifying Membrane Technology

Micro Filtration (MF) Bacteria, suspended particles

Ultrafiltration (UF) Colloids, macromolecules

Nanofiltration (NF) Sugars, dyes, divalent salt

Reverse Osmosis (RO) Monovalent salts, ionic metals

Particle Filtration (PF)

Water Water

Size of Common Materials

Pre-Treatment of Liquids Before Membrane Applications

Gravity Settling Tanks Hydrocyclones Centrifuges

Dead End Filtration Strainers Stainless Steel Screens Cartridge Filters Bag Filters Media Mycelx & Polymer Ventures – oil removal

Tubular Hollow Fibers Plates Spiral Wound Pleated Sheet

Membrane Types

Tubular Modules

Hollow Fiber Cartridges

Spiral Elements

Ceramic Membrane Elements and Modules

Expensive Long life: >15 years

Applications: Dairy, CIP solutions, Process water, Catalyst recovery

Scepter Membrane Elements and Modules

Expensive Long life: >15 years MF pore sizes only Applications:

Chemical clarification, Oil / Water separation, Starch recovery, Catalyst recovery

Fouling & Cleaning

Prevention – pretreatment

Membrane type, pore size, chemistry, process conditions, time Flushing & cleaning with chemical agents Sanitizing, storage and protection

Physical – back pulsing, back wash, back flush, air scouring

Pump

FEED Wastewater

Centrifuge/ hydrocyclones Screens, Bag filters, etc.

Pre-treatment

Permeate

Recycle

Chemical addition

Concentrate NF or RO System

Micro-filters

Post Treatment Water

Re-use

Texas A&M/GPRI Field Trailer Process Schematic

How Frac Flowback Brine is Cleaned Up for Re-Use

Raw Water Source

Reverse Osmosis

One Day Supply Tank for Raw Water

Large particulate removal

Oil & Grease removal

BTEX removal

TSS removal

Hardness removal

Desalination

pH, Temp., Conductivity, Turbidity,

Turbidity, O&G, BTEX

Turbidity, O&G

Turbidity, BTEX

Turbidity, BTEX, Conductivity

pH, Conductivity

pH, Conductivity,

Process Component

Identity Description Analytical Tests

Screen, Cartridge, Bag Filter

Cartridge

Media Filtration

Micro Filter

Nano Filter

Low Pressure Media Filtration

Oil and Grease Removal

Suspended Solids Filter Assembly

High Pressure Membranes and On-Line Sensors

Texas A&M GPRI DesignsTM Shale Field Trials

• Eagle Ford Shale Webb Co. -2 week test

• Range Resources Washington Co. PA - A 5 week test BG Exco Group Tioga Co. PA -3 week test

Pre-treatment, oil removal, microfiltration, nanofiltration On-site analytical

2012

• Eagle Ford Shale Cotulla, TX 2 Field Tests

Pre-treatment, oil removal, microfiltration, nanofiltration On-site analytical

2013

Mobile Unit On Site – New York

Mobile Unit On Site – Pennsylvania

Associated Costs Assessment

• Over 6000 barrels processed • Power cost of $0.10 kwh • Media pretreatment power averaged $0.004

per barrel • Solids removal $0.04 per barrel • Brine “softening” $0.84 per barrel • Total power cost ~ $1.00 per barrel of fluid

treated

Performance of Micro-Filtration

Sample No. Filter ID Pressure psig

Before Membrane NTU

After Membrane NTU

S-3, S-4 Koch hollow fiber micro-

filter 26 111.7 9.7

S-11, S-12 " 27.8 129.3 0.9

S-16, S-17 " 28.6 119.9 1.1

S-22, S-23 " 29.2 113.1 1

Sample No. Analyte Before Membrane mg/L

After Membrane mg/L

Type of Membranes

S-7, S-8 Sulfate 1025 92 Dow Spiral

S-7, S-8 Chlorides by titration 186,500 150,000

Hydranautics Spiral

S-60, S-61 Barium 183 103

S-70, S-71 Sulfate 150 23 GE Spiral

SN5 Iron 36.8 25

Nano-Filter Performance

Raw Feed Treated Water

Eagle Ford Samples

Why is Treatment Important? Decline in productivity that occurs in gas production – greater than reservoir engineering predictions

Frac Pond Brine, Eagle Ford, 2011

Untreated Treated

Example of Produced Water: Marcellus

Opposite the membrane wall is the counter for the analytical equipment

Hach Frac Brine Analysis Kit

Iron, Calcium, Magnesium, Sulfate, Turbidity, pH, etc.

GE Analytical TOC Analysis

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