The most common oxygen scavengers in oilfield production are sodium bisulfite (SBS) and ammonium bisulfite (ABS). Ammonium bisulfite is more water soluble than sodium bisulfite and typically react with oxygen faster. However, ammonium in the ammonium bisulfite can promote bacteria growth.

Being a salt of a weak acid and a strong base, sodium bisulfite forms a significantly basic aqueous solution whereas ammonium bisulfite is only slightly basic at around pH 8. As a rule of thumb, 60ppm of 65wt% ammonium bisulfite is required to reduce the oxygen concentration in water from 9ppm to 50ppb.

The reaction of bisulfite with oxygen is typically faster at higher temperatures and can be facilitated by transition metal ion catalysts, e.g. Cobalt.

The most common applications of oxygen scavenger in oil and gas production are for seawater injection facilities, hydro-testing, and acid stimulation

It is used to arrest oxygen in sea water

It removes Entrapped Oxygen and thus reduces Corrosion

In Oil Drilling Chemicals

When concentrated Sulfuric Acid and water are mixed, a tremendous amount of heat is released due to ionization of the acid. For instance, adding 1 volume of concentrated Sulfuric Acid to an equal volume of water (both at 25°C) results in a temperature rise to over 135°C. Therefore, the acid should always be diluted by adding it to the water. If the water is added to the acid, spattering could result which creates a hazardous situation and the possibility for severe chemical burns. The use of a 1 + 1 dilution of Sulfuric Acid with water (50% Sulfuric Acid, Group No. 8180) offers a much safer alternative in many instances when the use of Sulfuric Acid is required. For example, when 1 volume of concentrated Sulfuric Acid is added to 3 volumes of water, the temperature rises from 25°C to over 90°C. When the same solution is made by diluting 1 volume of 50% Sulfuric Acid with 1 volume of water, the temperature rises to less than 50°C.

IMPORTANT WARNING:
Accidental overdose of products containing iron is a leading cause of fatal poisoning in children under the age of 6. Keep this product out of the reach of children. In case of an accidental overdose, call your doctor or a poison control center immediately.

Why is this medication prescribed?.
Ferrous sulfate provides the iron needed by the body to produce red blood cells. It is used to treat or prevent iron-deficiency anemia, a condition that occurs when the body has too few red blood cells because of pregnancy, poor diet, excess bleeding, or other medical problems.

How should this medicine be used?.
Ferrous sulfate comes as regular, coated, and extended-release (long-acting) tablets; regular and extended-release capsules; and oral liquid (syrup, drops, and elixir) to take by mouth. Ferrous sulfate usually is taken three times a day between meals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take ferrous sulfate exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Although symptoms of iron deficiency usually improve within a few days, you may have to take ferrous sulfate for 6 months if you have severe iron deficiency.

This medication should be taken on an empty stomach, at least 1 hour before or 2 hours after eating.

Ferrous sulfate drops come with a special dropper for measuring the dose. Ask your pharmacist to show you how to use it. The drops may be placed directly in the mouth or mixed with water or fruit juice (not with milk).

Do not crush or chew regular, coated, or extended-release tablets, and do not open regular or extended-release capsules; swallow them whole.

Other uses for this medicine :

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

What special precautions should I follow?
Before taking ferrous sulfate,
•Tell your doctor and pharmacist if you are allergic to ferrous sulfate, any other medications tartrazine (a yellow dye in some processed foods and medications) or any of the ingredients in ferrous sulfate tablets, capsules, or liquid. Ask your doctor or pharmacist for a list of the ingredients.
•Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: chloramphenicol, cimetidine (Tagamet), levodopa (Larodopa, Sinemet), methyldopa (Aldomet), penicillamine. Your doctor may need to change the doses of your medications or monitor you more carefully for side effects.
•if you also are taking cinoxacin (Cinobac), ciprofloxacin (Cipro), demeclocycline, doxycycline, enoxacin (Penetrex), levofloxacin (Levaquin), lomefloxacin (Maxaquin), methacycline, minocycline, nalidixic acid (NegGram), norfloxacin (Noroxin), ofloxacin (Floxin), oxytetracycline, sparfloxacin (Zagam), or tetracycline, take it 3 hours after or 2 hours before taking ferrous sulfate. Do not take antacids at the same time as ferrous sulfate; take them as far apart as possible.
•Tell your doctor if you have or have ever had ulcers, colitis, or intestinal disease.
•Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking ferrous sulfate, call your doctor.
talk to your doctor about the risks and benefits of taking this medication and the proper dosage if you are 65 years of age or older. Older adults should only take lower doses of ferrous sulfate because higher doses may not be more effective than lower doses and are more likely to cause constipation.

What special dietary instructions should I follow?
Fish, meat (especially liver), and fortified cereals and breads are good dietary sources of iron; emphasize them in a well-balanced diet.

What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?
Ferrous sulfate may cause side effects. Your stools will turn dark; this effect is harmless. Your teeth may stain from the liquid; mix each dose with water or fruit juice. You may clean your teeth once a week by rubbing them with a small amount of baking soda.

Tell your doctor if either of these symptoms is severe or does not go away:
•constipation

•stomach upset

If you experience a serious side effect, you should report directly to doctor

This medication may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.

What storage conditions are needed for this medicine?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose.
In case of overdose, call your local poison control center

What other information should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to ferrous sulfate.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.