Product Information

UCARCIDE SB 130 Antimicrobial CAS Reg. No. 111-30-8 EPA Reg. No. 464-718 General

The UCARCIDE™ family of oilfield antimicrobials are glutaraldehyde-based biocides which have found widespread use in a variety of oil and gas operations. The Dow Chemical Company offers several different UCARCIDE Antimicrobial formulations that are ideally suited to meet the diverse demands of most oil and gas applications. Until now, all of the UCARCIDE products were aqueous solutions of glutaraldehyde; however, UCARCIDE SB 130 Antimicrobial is a granular form of glutaraldehyde that was developed for those customers who prefer to handle solid products.

Structure

O

H

Physical Properties

O

H

The following are typical properties of UCARCIDE SB 130 Antimicrobial; they are not to be considered product specifications. Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Opaque, white granular powder Active, % Glutaraldehyde (% by weight) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 pH @ 25°C: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 to 4.5 Solubility in Water @ 20°C: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Bulk Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70g/100 mL Vapor Pressure @ 20°C: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 Torr

Features and Benefits

UCARCIDE SB 130 Antimicrobial is a free flowing, granular product that releases glutaraldehyde when added into an aqueous system. It contains approximately 30% glutaraldehyde, 30% water and 40% non-dusting (amorphous hydrated) silica that will not dissolve in water. As such, this product is ideal for uses in those applications that can tolerate the presence of an insoluble material, such as drilling and fracturing fluids. The product is packaged in a reclosable container for ease of handling and use. UCARCIDE SB 130 Antimicrobial provides all of the benefits that are expected of a glutaraldehyde-based biocide, but now in a granular form for those who would rather handle a solid product.

The Rate of Release of Glutaraldehyde

An important aspect of the new granular product is how fast the glutaraldehyde releases from the silica carrier when it is added into water. In order to determine this, a sample of UCARCIDE SB 130 Antimicrobial was added into water in such amount as to yield 100 ppm of active glutaraldehyde. The solution was stirred and aliquots were taken and analyzed for glutaraldehyde content by gas chromatography. The following graph shows the rate of release of glutaraldehyde into the water.

Page 1 of 7

Form No. 253-01534-10/06/03

100

ppm Glutaraldehyde Released

Release of Glutaraldehyde from UCARCIDE SB 130 Antimicrobial

80

ppm GA

60

40

20

0 0

20

40

60

80

100

120

140

Time (Minutes)

The graph shows that over 80% of the glutaraldehyde is released off of the silica carrier within 5 minutes of contact with the water. All of the glutaraldehyde is subsequently released within 30 minutes of being placed in the water. This demonstrates that the silica does not bind the glutaraldehyde in such a way as to prevent its release in an aqueous system. Efficacy of Solid Glutaraldehyde Versus Liquid Glutaraldehyde

Knowing that glutaraldehyde is quickly released from the silica carrier, the next step was to ensure that glutaraldehyde released from the solid demonstrated the same efficacy as the liquid glutaraldehyde. To do so, a comparative efficacy study of both products was run in water collected from a nearby pond. This particular surface water was chosen to test the efficacy of the solid glutaraldehyde product in order to simulate the conditions and type of water that may be encountered in the field (to formulate a drilling mud or fracturing fluid, for example). The concentrations tested are in ppm; active ingredient and results are shown below.

CFU/mL

Comparison of Efficacy of Solid Glutaraldehyde vs Liquid Glutaraldehyde

10

6

10

5

10

4

1000 25 ppm Solid GA 25 ppm Liquid GA 100 ppm Solid GA 100 ppm Liquid GA Control

100

10

1 0

Page 2 of 7

1

2

3 4 Time (Hours)

5

6

7

8

Form No. 253-01534-10/06/03

As the graph shows, equal concentrations of glutaraldehyde arising from either the liquid product or the solid product delivered equal efficacy against the microorganisms in this surface water. This experiment provides definitive proof that the glutaraldehyde that is released from the silica carrier retains its biocidal activity and is not in any way affected by its absorption onto the carrier during manufacture. Comparative Efficacy of UCARCIDE SB 130 Antimicrobial and Solid Isothiazolone in a Fracturing Fluid

To demonstrate the efficacy of UCARCIDE SB 130 Antimicrobial in a fracturing fluid, the components of an actual fracturing fluid were obtained and formulated according to the supplier’s instructions. The source of the water used was the same pond water that was used in the experiment described above in order to introduce a source of environmental microorganisms. UCARCIDE SB 130 Antimicrobial and a solid isothiazolone product were dosed into the fracturing fluid at various concentrations and samples were taken after 30 minutes, 2 hours, 24 hours, 48 hours and 5 days of contact and plated out to determine the reduction in viable organisms. The aliquots were re-challenged with contaminated fracturing fluid on day 5 and sampled for the final time on day 7. Before the re-challenge on day 5, the viscosity of the fluid was measured with a Brookfield viscometer to determine whether or not the microbes had degraded the rheological properties of the fluid. The results are shown in the table below. Contact time (CFU/mL remaining)

Biocide (ppm Active Ingredient)

7 Day

5 Day

30 Minute

2 Hour

24 Hour

48 Hour

5 Day

Re-Challenge

Viscosity

UCARCIDE SB 130 Antimicrobial 100 ppm

400

200

7

4

4

1

132 cP

UCARCIDE SB 130 Antimicrobial 200 ppm

200

150

6

0

0

4

136 cP

UCARCIDE SB 130 Antimicrobial 300 ppm

200

400

7

1

0

0

128 cP

Isothiazolone @ 10 ppm

430,000

20,300

300

300

300

600

76 cP

Isothiazolone @ 20 ppm

390,000

18,000

300

180

200

500

76 cP

Isothiazolone @ 30 ppm

340,000

20,800

500

200

200

300

92 cP

Control

4.0 X 106

2.9 X 106

1.0X107

5.0X107

1.0X108

1.4X108

0 cP

Both the UCARCIDE SB 130 Antimicrobial and the solid isothiazolone performed well over the 7-day test period, even after an additional microbial challenge at 5 days. The solid glutaraldehyde product, however, gave a faster and more complete kill than did the solid isothiazolone. In addition, the viscosity of the glutaraldehyde treated fluids was higher than the viscosity of the isothiazolone treated fluid. Since a loss of viscosity is an indicator of degradation of the fluid, it appears that the glutaraldehyde treated fluids retained more of their rheological properties than did the isothiazolone treated fluids. Comparative Efficacy of UCARCIDE SB 130 Antimicrobial and Solid Isothiazolone in a Drilling Mud

Page 3 of 7

To complement the efficacy study that was run in the fracturing fluid, the efficacy of the UCARCIDE SB 130 Antimicrobial in a drilling mud was also evaluated. A commercial drilling mud sample from the field, that had been prepared without any biocide, was obtained. The sample was quite contaminated as received and presented an excellent opportunity to demonstrate the efficacy of UCARCIDE SB 130 Antimicrobial in an actual field sample of a drilling mud. As before, the efficacy of the solid glutaraldehyde product was determined in comparison to the efficacy of the solid isothiazolone product. The results are shown in the following table.

Form No. 253-01534-10/06/03

Contact Time (CFU/mL remaining) Biocide (ppm active ingredient)

30 Minute

2 Hour

24 Hour

4 Day

5 Day

UCARCIDE SB 130 Antimicrobial, 25 ppm

2.E+03

5.E+02

1.E+05