Ageing of oil fields is a perpetual and crucial concern facing the global oil industry. Thousands of oil wells in such fields fall in the category of stripper wells producing small to insignificant quantities of oil.
To enhance oil production from these stripper wells, joint research of ONGC, IRS & TERI lead to improved Microbial technology of cultured set of microbes that could survive temperatures as high as 90ºC, air pressure up to 140 kilograms per square centimeter, and strong salinity with concentration levels ranging from 4% to 8%. These microbes were successfully field tested in oil wells of Gujarat and Assam and the application of this technology is through Huff & Puff method where microbial injection & oil production is done through the same well.
After these microbes & its nutrients are injected into an oil well, they take close to three weeks to proliferate & produce useful metabolites like Bio-surfactants, Biopolymers, Fatty acids & Gases in the reservoir very near to the wellbore, which help to increase the oil production through reduction in interfacial tension, reduction in oil viscosity, increase in pore throat pressure & altering the rock wettability causing reduction in water cut. The MEOR process of oil recovery actually offers more advantages than conventional EOR methods of oil recovery in such reservoirs.
2. MEOR JOB BY OTBL IN India
ONGC, Ahmedabad Asset (Cambay Basin)
OTBL has executed 50 MEOR jobs in oil wells of 5 fields of ONGC, Ahmedabad Asset. The tabulated field wise execution status of these jobs is as follows:
|Field Name||No of MEOR Jobs executed|
The commercial success ratio of these jobs has been of the order of 60% where as technical success has been over 80%.
ONGC, Assam Asset (Assam Arakan Basin)
Out of 15 MEOR jobs awarded to OTBL by ONGC, Assam Asset, OTBL has field executed 9 jobs in 2 fields. The tabulated detail of executed jobs is as under:
|Field Name||No. of MEOR Jobs executed|
ONGC, Ankleshwar Asset (Cambay Basin)
OTBL has executed 12 MEOR jobs at ONGC, Ankleshwar Asset.