Biocides

Weschem Production Technologies Ltd. manufactures a wide variety of biocides that control each of the following types of corrosion:

AEROBIC

ANAEROBIC

SLIME FORMING BACTERIA

Weschem Production Technologies Ltd corrosion biocides are used by the following types of industries:

METAL WORKING INDUSTRIES

OIL AND GAS PRODUCTION

OIL AND GAS WATER INJECTION WELLS

REFINERIES

WATER TREATING, COOLING TOWERS

SERVICE AND TECHNICAL EXPERTISE

Weschem Production Technologies Ltd will analyze your application to help determine the most effective and economical methodology and product.

BIOCIDES GENERAL DISCUSSION

Weschem Production Technologies Ltd. offers a series of effective biocides to control the growth of micro organisms in water floods, injection systems, disposal wells, producing systems and water towers. The two main bacteria types are aerobic (which require oxygen) and anaerobic (which do not require oxygen and are intolerant to oxygen). Anaerobic bacteria can propagate in oxygenated environments if they are protected from the oxygen (e.g. under slime, corrosion and/or scale deposits).

Sulfphate Reducing Bacteria (SRB’s) are the most common form of oilfield bacteria. The SRB’s reduce sulfate ions into hydrogen sulfide which can cause severe corrosion especially under deposits where there is a significant level or high concentration of hydrogen sulfide. This results in severe localized pitting.

These antimicrobiological chemicals are effective against aerobic and anaerobic (sulfate reducing) organisms as well as slime forming algae and fungi.

The best biological program will fail if applied to a dirty system. Therefore, any system should be cleaned to remove all deposits where undesired micro organisms can “hide” from the biocide.

The most effective biological program will be by alternating between two effective biocides. This prevents the organism from mutating and thereby developing a resistance to the biocide. Generally, a frequent batching of the biocide at higher concentration will be more effective than using the same amount of biocide on a continuous injection program. Batch programs are normally sized so as to provide a contact time of 4 to 8 hours for the biocide to thoroughly kill the bacteria.

The frequency and dosage levels of Biocide programs is generally determined by the results of monitoring tests (including “bug” bottle testing and corrosion coupon testing for sessile bacteria)in order to both optimize the program and to determine the appropriate levels necessary for the operating conditions at the time.

In some severe cases, a combination of batch treatment and continuous injections may be used.

There are four factors that should always be kept in mind when “bug” bottle testing.

1) If more than the first bottle turns, “bugs” are present.

2) If the test is negative, it only means that there were no organisms present in that sample or that the organisms failed to be cultivated in that test medium.

3) Hydrogen sulfide (from sour systems) can cause the first bottle to indicate a positive test even in the absence of sulfate reducing bacteria.

4) Air accidentally introduced into the test bottle can indicate a false positive test.

To determine the best biocide for your application, contact our personnel who can evaluate your system based on brine levels, sufactancy requirements, foaming characteristics, compatibility with other chemicals, etc.

Weschem Production Technologies Ltd. also supplies the microbiological monitoring systems for bacteria control.

APPLICATIONS:

The different types of biocide application are batch treatment, continuous treatment and squeeze treatment or variation thereof.

BATCH TREATMENT:

STANDARD BATCH The inhibitor can be added undiluted or diluted .

Dilution rate is usually 1 part inhibitor to 10 parts solvent or diluent. At least 1,000 ppm inhibitor should contact the surface to be treated, depending upon the severity of the bacteria that are present. The facilities should be treated often enough to maintain protection, consistent with the severity of attack and production rate.

CONTINUOUS TREATMENT

Pipelines, flowlines, injection wells, and producing wells can be treated continuously by injecting biocide directly into the system at a rate of 10 to 100 parts per million based upon flow or production.

WATER INJECTION WELLS are typically treated by continuous injection of biocide. Compatibility of these biocides at the actual use rate should be checked with other chemicals being utilized

PIPELINES can be treated continuously or by batch. They may be batched treated with slugs of inhibitor between pigs to ensure full contact.

Continuous treatment with occasional batching with an alternate biocide is particularly effective. Your Westhaven representative will analyze the optimal treatment methods.

DISCLAIMER OF LIABILITY

The information in this bulletin is believed to be accurate but all recommendations are made without warranty, since the conditions of use are beyond Weschem Production Technologies Ltd. control. The listed properties are illustrative only and not product specifications. Weschem Production Technologies Ltd. disclaims any liability connection with the use of the information. The use of these products being beyond the control of the manufacturer, no guarantee, expressed or implied, is made as to the effects of such or the results to be obtained if not used in accordance with directions or established safe practice. The buyer must assume all responsibility, including injury or damage, resulting from its misuse as such, or in combination with other materials.