ADDITIVE NEWS OG-AN 3

BYK-GO 8780 – an effective hydrogen sulfide scavenger
The use of a liquid additive to control hydrogensulfide in oilfield applications
Hydrogen sulfide (H2S) gas is one of the most dangerous
hazards in the oil and gas industry. Formed by the decay oforganic matter containing sulfur, H2S gas is both highly toxicand flammable. H2S can enter drilling fluids when drillingthrough subsurface formations or from sulfate-reducing
bacteria that produce H2S.
Not only is H2S deadly, but it can also cause sulfide stresscorrosion cracking in metals, such as casing. Luckily, withproper monitoring and control procedures in place, H2S canbe precipitated from both water-based and oil-based
drilling fluids by treatment with an H2S scavenger.
BYK has developed an H2S scavenger that is commerciallyavailable. BYK-GO 8780 is a 15 % active general-purpose
scavenger based on zinc ammonium carbonate, which canquickly and thoroughly eliminate the threat of H2S throughthe precipitation of zinc sulfide. The liquid form allows fora more rapid precipitation rate than those exhibited bypowdered zinc containing H2S scavengers.
BYK used a third-party independent lab to conduct a study
to determine the effectiveness of BYK-GO 8780 H2Sscavenger in a water-based drilling fluid and a non-aqueous
drilling fluid. H2S detection tests were carried out via aGarrett Gas Train.
For the water-based formulation, a low-solids, non-dispersed
drilling fluid was formulated, and the pH was adjusted to 10.5.
The base mud was compared against two levels of BYK-GO
8780 H2S scavenger, pure zinc oxide, and 80 % triazine.

5.75 lb/bbl of a 98 % assay sodium sulfide nonahydrate
was added to each sample and hot rolled at 150 °F forfive hours. Sodium sulfide is basic, converting to H2S basedon the pH of the drilling fluid. The following procedure wasused for the evaluation:• Mix the water and bentonite for 10 minutes.
• Add the xanthan gum and mix for 10 minutes.
• Add the lignite and mix for 10 minutes.
•	Adjust the pH to approximately 10.5 using sodiumhydroxide.

•	Add the required amount of H2S scavenger and mix for
one hour using a multi-mixer.
• Add sodium sulfide nonahydrate to each sample.
•	Immediately close and seal the aging cells and hot roll at
150 °F for five hours.
• Collect filtrate from each sample using API fluid loss.
• Test for H2S content via Garrett Gas Train.
The graph below demonstrates the efficiency of
BYK-GO 8780, triazine, and zinc oxide at different
treatment levels in the water-based formulation.

H2S scavengers evaluation in water-based mud
H2S ppm remaining
1800
1600
1400
1200
1000
800
600
400
20000Base mud

ZnO
1.0 lb/bbl

ZnO
2.0 lb/bbl

Triazine (80 %)1.0 lb/bbl

Triazine (80 %)3.0 lb/bbl

BYK-GO 8780
4.25 lb/bbl

BYK-GO 8780
8.5 lb/bbl

A treatment of 8.5 lb/bbl of BYK-GO 8780 contained
1.3 lb/bbl of zinc. This treatment level effectively removed
all the H2S compared to 2.0 lb/bbl zinc oxide, which left
significant levels of H2S in the system. 3.0 lb/bbl of 80 %triazine contained 2.4 lb/bbl of active triazine. At thistreatment level, unsafe levels of H2S remained in the testsystem. For the aqueous trial on an active basis, BYK-GO 8780
was the most efficient treatment for removing H2S.

The versatility of BYK-GO 8780 allows for the same productto be used in non-aqueous drilling fluids. A non-aqueous
10.0 pound per gallon of drilling fluid was formulated in asynthetic base fluid. As with the aqueous formulation above,
5.75 lb/gal of sodium sulfide nonahydrate was added as thesource of H2S generation. The system was hot rolled at
150 °F for 4 hours. For this evaluation, BYK-GO 8780 wasevaluated against zinc oxide. The results are summarized in
the graph below.

The results were similar in the non-aqueous fluid to thoseexhibited in the aqueous fluid. 8.5 lb/bbl of BYK-GO 8780
with an active level of 1.3 % active zinc had a 9x efficacy
over the 2.0 % zinc oxide, reducing the H2S by 92 %.
BYK-GO 8780 is an effective sequestrant of H2S in bothaqueous and non-aqueous fluids, and an excellent addition
to your safe drilling program.

H2S scavengers evaluation in synthetic-based mudH2S ppm remaining
20001800
1600
1400
1200
1000
8006004002000

BYK-Chemie GmbH
Abelstraße 4546483 Wesel
GermanyTel +49 281 670-0
Fax +49 281 65735
info@byk.com
www.byk.com

ZnO
1.0 lb/bbl

ZnO
2.0 lb/bbl

BYK-GO 8780
4.25 lb/bbl

BYK-GO 8780
8.5 lb/bbl

ADD-MAX®, ADD-VANCE®, ANTI-TERRA®, AQUACER®, AQUAMAT®, AQUATIX®, BENTOLITE®, BYK®, BYK-AQUAGEL®, BYK®-DYNWET®, BYK-MAX®, BYK®-SILCLEAN®, BYKANOL®, BYKCARE®,
BYKETOL®, BYKJET®, BYKO2BLOCK®, BYKONITE®, BYKOPLAST®, BYKUMEN®, CARBOBYK®, CERACOL®, CERAFAK®, CERAFLOUR®, CERAMAT®, CERATIX®, CLAYTONE®, CLOISITE®, DISPERBYK®,DISPERPLAST®, FULACOLOR®, FULCAT®, GARAMITE®, GELWHITE®, HORDAMER®, LACTIMON®, LAPONITE®, MINERPOL®, NANOBYK®, OPTIBENT®, OPTIFLO®, OPTIGEL®, POLYAD®, PRIEX®,PURABYK®, PURE THIX®, RECYCLOBLEND®, RECYCLOBYK®, RECYCLOSSORB®, RECYCLOSTAB®, RHEOBYK®, RHEOCIN®, RHEOTIX®, SCONA®, SILBYK®, TIXOGEL® and VISCOBYK® are registeredtrademarks of the BYK group.
The information herein is based on our present knowledge and experience. The information merely describes the properties of our products but no guarantee of properties in the legal sense
shall be implied. We recommend testing our products as to their suitability for your envisaged purpose prior to use. No warranties of any kind, either express or implied, including warranties ofmerchantability or fitness for a particular purpose, are made regarding any products mentioned herein and data or information set forth, or that such products, data or information may be usedwithout infringing intellectual property rights of third parties. We reserve the right to make any changes according to technological progress or further developments.
This issue replaces all previous versions.

ADDITIVE NEWS OG-AN 3
07/2022

Base mud