Paraffin deposition problems in producing oil systems has been a problem for decades. Most traditional solutions to this problem pose safety problems or utilize toxic substances. By utilizing a biological process, paraffin can be controlled without safety or toxicity concerns. Three biological systems were tested and each showed positive results in controlling downhole paraffin problems. Over five hundred individual wells were treated with one or all three of these systems and results are compared. In addition to controlling paraffin, some wells showed noticeable production increases. One hundred and three wells which had been treated biologically for one year or longer were analyzed for production decline changes.
In over thirty percent of the wells investigated, production improvements resulted.
The terminology "paraffin deposit" is commonly used in the oil industry to refer to a waxy material which is precipitated out of a crude oil onto the surfaces of production equipment. This deposit may consist of paraffin's, asphaltenes, oil, water, sand and other debris. Excessive precipitation of this waxy component on production equipment will cause production problems. Historically oil producers have dealt with the paraffin problem by removing or inhibiting deposition by thermal, mechanical and chemical processes.
During the last three years Kiseki has treated a large number of wells successfully utilizing biological products for prevention of paraffin problems.
It is a well known and documented fact that bacteria will metabolize hydrocarbons. However, the metabolic pathways of hydrocarbon degradation are not completely understood. It is known that alkenes can be oxidized resulting in the generation of several intermediate and end products. Oxidation of the terminal (C1) methyl group results in an alcohol, aldehyde and subsequently a carboxylic acid. To a lesser extent the C2 carbon may be oxidized to give a methyl ketene or the oxidative attack may take place at both ends to give an (alpha) dicarboxylic acid. (1)
Paraffinic hydrocarbons are generally metabolized more rapidly and by more microbial species than aromatic compounds. As a rule, long chain hydrocarbons are metabolized more readily and by more microbial species than those of low molecular weight. The susceptibility of petroleum products to microbial oxidation generally increases with the melting or boiling point. For example, paraffin wax is oxidized preferentially to gasoline. (2)
The three product systems which were used for the treatment of wells for paraffin problems are comprised of hydrocarbon oxidizing micro-organisms.
The products are different proprietary mixed cultures of naturally occurring microorganisms.
Product #1 and #2 are liquid mixtures of facultative anaerobes. Cell concentration was reported by the manufacturers to be 106 - 109 cells/ml. These products are transported in 55 usg drums containing biological cells, water and nutrients.
Product #3 is a mixture of aerobic bacteria produced in powder form. Cell concentration is 1012 cells/gm. In addition to the powder bacteria this product system includes a liquid bio-catalyst and an inorganic nutrient.
All three product systems are nonhazardous, non toxic non carcinogenic and non pathogenic and therefore very safe to handle in the field.