Bentonite Plug Laboratory Testing

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Anita Khannikova

Blake Fossen

John Jeffress

William Thomas

Keith Herring

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Presentation Outline

Objective Background

Laboratory safety

Pressure testing equipment Casing preparation

Quality control for pressure readings Various plug compositions

Plug testing data

Implemented recommendations Ethics

Environmental impact

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Objective

Investigate possibility of plugging and abandoning (P&A) wells with manufactured organic plugs

Simulate downhole conditions in the laboratory  Temperature

 Salinity  Pressure

Pressure test breaking point of designed bentonite plugs

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Background

Conventional cement plugging method  Expensive

 Excess equipment and personnel required  Labor and time intensive

 Tubing and tripping time for spotting cement plugs Bentonite plugging

 Economically favorable  Environmentally safe

 Minimal equipment and personnel required  Self-healing after seismic activity

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Laboratory Safety

Perform safety evaluation

 Proper MSDS accessible in laboratory

 Pressure ratings on flanges, valves, and general fittings  Proper personal protective equipment (PPE)

 Organized the lab to prevent slips, trips, and fall hazards Laboratory inspection

 Cleaned laboratory

 Organized and inspected all tools and equipment  Conducted inventory

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Pressure Testing Equipment

Five – 10’ joints of 4 ½” I.D. casing

 Cleaned casing flanges and inspected gaskets  Flange caps installed on casing

 Rigged up pressure manifold from casing to pump  Isolation valves installed on each flange cap

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Casing Preparation

 Rocks used for permeable barrier between plugs and testing manifold  Larger rocks eliminate infiltration into

manifold

 Eliminates possibility of inaccurate pressure readings

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Pressure Testing Equipment

Quality Control

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Bentonite alcomer polymer plug concentration  0.15 grams alcomer-24 polymer

 1518 grams bentonite pellets  152 grams fresh water

Bentonite wood glue plug concentration  92.2 grams wood glue

 1476 grams bentonite pellets  81.7 grams fresh water

Bentonite x-link polymer plug concentration  0.15 grams x-link polymer

 1518 grams bentonite pellets  152 grams fresh water

Sepiolite plug concentration

 1450 grams sepiolite pellets

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Plug Installation and Hydration

Installation

 12 – 6” plugs manually inserted by dropping individual plugs into upper (open) end of casing

 Casing filled with desired hydrating solution prior to plug installation  Brine solutions were prepared using 151.1 grams of salt per 4 gallons

of water which equates to a 10,000 ppm solution

 Plugs rest on top of permeable barrier of 2” river rocks Hydration

 Plugs allowed to hydrate for minimum of two weeks at ambient temperature and pressure prior to testing

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Bentonite Alcomer Polymer Plug in Fresh Water

0 100 200 300 400 500 600 0 20 40 60 80 100 120 140 160 180 Br eak thr oug h Pr essur e (p sig )

Cumulative Hydration Time (days)

Casing#1- Fresh Water Casing#2- Fresh Water

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Bentonite Alcomer Polymer Plug in Salt Water

0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 Br eak thr oug h Pr essur e (p sig )

Cumulative Hydration Time (days)

Bentonite Alcomer Polymer Plug - 10,000 ppm Salt Water

Bentonite Alcomer Polymer Plug - 20,000 ppm Salt

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Current vs Previous Bentonite Wood Glue Plugs in

10,000 ppm Salt Water

0 20 40 60 80 100 120 140 0 20 40 60 80 100 120 Br eakthrough Pr ess ur e (psi g)

Cumulative Hydrating Time (days)

Current Bentonite Lab Group Previous Bentonite Lab Group

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Bentonite Plugs in Fresh Water

0 50 100 150 200 250 300 350 400 450 10 15 20 25 30 35 40 45 Br eak thr oug h Pr essur e (p sig )

Bentonite X-Link Polymer Plug Bentonite Alcomer Polymer Plug -Casing #1

Bentonite Alcomer Polymer Plug -Casing #2

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Bentonite Plugs in 10,000 ppm Salt Water

0 10 20 30 40 50 60 70 80 90 100 10 15 20 25 30 35 40 45 Br eak thr oug h Pr essur e (p sig )

Bentonite Wood Glue Plug

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Plug composition consisting of a salt water gel rather than a fresh water gel

 Salt water breaks down bentonite  Sepiolite yields in salt water

 Potentially higher breaking pressures in salt water

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Swelling Potential of Sepiolite

Manufactured sepiolite plug  Length – 6 in

 O.D. – 3.5 in  I.D. – 1.0625 in

 Total volume = 52.41 in3

24 hour hydrated sepiolite plug in 10,000 ppm salt water

 Length – 6.5625 in  O.D. – 4.0 in

 Final volume = 82.47 in3

Total increase in volume = 30.06 in3

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Sepiolite Plug in 10,000 ppm Salt Water

0 20 40 60 80 100 120 140 10 15 20 25 30 35 40 45 Br eak thr ou gh Pr essu re (p sig )

Sepiolite Plug

Bentonite Wood Glue Plug

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Hydrate plugs under pressure

 Better simulate downhole conditions

 Plugs set at 3,000 ft in fresh water hydrate under 1,300 psi  Installed additional manifold and piping

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Hold paramount the safety, health, and welfare of the public  Record accurate pressure data

 Develop better plugs

 Simulate down hole conditions

 Stand behind our product with confidence Successfully execute field trial

 Gain industry support

 Replace traditional cement methods

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Environmental Impact

Bentonite and Sepiolite

 Natural mineral extracted from the earth  Low impact on environment

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Plug Testing

 Hydrate plugs under pressure  Simulate downhole temperatures  Field Trial

Enhancing Plug Development

 Adding guar to sepiolite plugs

 Continue research for salt water applications

 Decrease inside diameter of plug from 1-1/16” to 7/8”

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Project Summary

• Improved lab safety • Quality control

• Simulate downhole conditions

• Developed plug for salt water application

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Special thanks to:

Dr. Brian Towler - Professor and CEAS Fellow for Hydrocarbon Energy Resources

Kyle Winkelman - Safety Coordinator Mike Redburn - Newpark Drilling Fluids

David C. Rachford - IMV Nevada