KOHIMA, March 18: The ONGC has so far drilled 30 exploratory oil wells at Changpang area under Wokha district, out of which nine were producing oil on trial basis but had been suspended since 1994, reports UNI. The annual administrative report which was tabled in the State Assembly by the Geology and Mining Department on Thursday, mentioned that four exploratory oil wells at Chumukedima-Tenephie area in Dimapur district and one in Changki area under Mokokchung district were drilled by ONGC, but these wells had not yielded positive results due to hydro-carbon deposits. The commission had so far extracted about 10.22 lakh tonnes of crude oil from March 1980 to May 1991, for which a royalty of approximately Rs 33.83 crore was earned as revenue by the state government. The report also said the department was trying to reactivate the oil and natural gas deposit of the State to explore it under new modalities.