ONGC adopts output enhancement process

Oil and Natural Gas Corporation Ltd (ONGC), which is facing declining crude oil production, has taken steps to increase oil output at its existing wells. The focus of the plan will be on its wells in Gujarat and Assam.

ONGC on Thursday introduced the microbial enhanced oil recovery (MEOR) process, conceived with technical expertise of the Institute of Reservoir Studies (IRS), Ahmedabad, and Tata Engineering and Research Institute (TERI) at its well No. 36 of Sobhasan field in Mehsana, Gujarat.

"With declining oil production, we have now taken steps to increase crude oil production at our existing wells, especially at those with a depleting oil layer. The implementation of the MEOR process was kicked off in Mehsana on Thursday which will help ONGC to raise its oil production.

In ONGC's three assets in Gujarat "" Ahmedabad, Mehsana and Ankleshwar "" we have depleting oil wells. With the introduction of MEOR, we are going to maximise oil recovery," said Subir Raha, chairman and managing director, ONGC, at a function to implement the technology at the Sobhasan field.

Also present at the function was R K Pachauri, director general of TERI, and chairman of the institution Inter-governmental Panel on Climate Change (IPCC). The company at present produces eight million tonne of crude oil at the Mehsana well.

ONGC's crude oil production, which was at 31.63 million tonne at the end of fiscal 1995-96, came down to 25.05 million tonne during fiscal 2000-01 which again declined to 24.7 million tonne in the next year. The production again jumped to 26.41 million tonne by the end of last fiscal.

"By the end of this fiscal, we hope to record a production of 27 million tonne. With the implementation of the MEOR technology, we expect oil recovery and subsequently production to be raised in the next one year. After Gujarat, we will implement the technology at our oil fields in Assam. At Mumbai High we have recently launched the enhanced oil production (EOR) technology to raise oil recovery," Raha said.

This technology has already been patented by ONGC for its operations in India, while it has already filed an application for registration of patent for its exploration sites outside India.

The MEOR process is basically a huff and puff stimulation technique applied in oil wells producing with higher water cut.

The physico-chemical changes induced to saturate hydrocarbons by injecting bacteria into oil reservoirs along with suitable nutrient medium reduces the pour point and viscosity of the oil in reservoir condition.

"The technology earlier was for the oil wells where microbes can survive up to 65 degree centigrade. With this technology, microbes can survive up to 90 degree centigrade," said Raha.

The MEOR process will be applied in five wells of ONGC's Mehsana asset. Eight wells have also been identified for execution of the process.