Possible Use of Bacteria/Steam to Treat Asphaltene Deposition in Carbonate Rocks

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIn this project bacteria and steam were tested to stimulate limestone cores damaged by asphaltene deposition. Several dynamic experiments were conducted to determine the effect of asphaltene on the permeability of limestone cores. Plugging effects due to asphaltene deposition were evaluated through a comparison between permeability measurements after oil flow and the reference permeability measured prior to oil flow. Damaged cores were subjected to bacteria and/or steam and the permeability of the cores was measured after each treatment. Core impairment resulting from in-situ asphaltene deposition was found to cause a 56 to 89% loss of initial oil permeability depending on rock permeability and injection rate. Core stimulation results from direct bacteria treatment, was found to cause a 3 to 105% improvement on the damaged core permeability depending on core permeability and the extent of the damage. Bacteria treatment results were compared to steam treatment of the damaged cores.

Experimental and Modeling Study on Precipitated Asphaltene Biodegradation Process Using Isolated Indigenous Bacteria

“…Therefore, it seems to be very necessary to identify and apply some asphaltene precipitation inhibitors as well as removal methods in various crude oil production and transition stages. Some chemicals and nonchemical inhibition methods have been proposed, and their performance was compared with each other. − Furthermore, some applicable removal techniques such as physical methods, including wireline cutting, pigging, and hydro-blasting; thermal methods, , including hot oil or water vapor injection and using a laser and a heater in bottom of the well; chemical methods, such as the use of aromatic solvent and oil-soluble amphiphiles; and finally microbial methods, besides a combination of them have been presented. Extensive use of oil productions and chemical compositions imposes extreme damage to the environment.…”

Effect of Various Isolated Microbial Consortiums on the Biodegradation Process of Precipitated Asphaltenes from Crude Oil

“…The polymerase chain reaction (PCR) was performed on a thermal cycler by using 25 μL reaction mixture. The reaction mixture contains 1, 12.5, 9.5, and 1 μL of each forward and reverse primers, master mix 2×, Milli-Q water and genome, respectively . The reaction mix was exposed to the denaturation process at 94 °C for 5 min; next, the amplification was performed with 25 cycles of 1 min at 94 °C, 40 s at 55 °C, 2 min at 72 °C chased by 1 cycle extension of 10 min at 72 °C .…”

“…Asphaltene precipitation from reservoir fluids in all stages of oil production and transportation causes a serious problem and increases the cost of production. − Because of these problems, it seems to be mandatory to find and employ asphaltene precipitation removal methods such as chemical methods, physical techniques, thermal methods, and microbial methods. − Recently, biological processes as one of the affordable and environment-friendly methods have encouraged researchers to use them in removing precipitated asphaltenes. Hydrocarbon biodegradation is a very important mechanism that causes the elimination of crude oil and other pollutant hydrocarbons from ecosphere …”

Asphaltenes – Problems and Solutions in E&P of Brazilian Crude Oils

“…The deposition of asphaltenes can also happen in separators during the final stage depressurization of oil (Almehaideb and Zekri, 2001), as well as in almost all stages of production, processing and transportation of oil and is an extremely serious problem that affects significantly the costs of oil industry.…”