Guwahati, June 26 : State-owned Oil and Natural Gas Corporation Limited (ONGC) is hopeful of plugging the gas blowout in one of its wells in Assam's Sivasagar district by Friday, sources said on Thursday.

ONGC sources said that with steady progress and a focused operational roadmap, ONGC is optimistic about completing the snubbing operation before sundown on Friday. The corporation remains committed to executing every stage of the operation with utmost precision, safety, and environmental responsibility, he said.

According to an expert, snubbing in the oil and gas industry refers to a well intervention technique where equipment like pipe or coiled tubing is pushed into a wellbore under pressure, often when the well cannot be killed or shut down.

This is achieved using a snubbing unit, which is a specialised hydraulic workover rig. Snubbing is a vital process for various operations, including running equipment, addressing well control issues, and performing maintenance in pressurised wells, the expert said.

The company sources said that ONGC, in close coordination with international well control specialists from CUDD Pressure Control, achieved a key breakthrough on Thursday in its ongoing operations at Well RDS-147A.

The team successfully cleared all remaining rig materials, including staircases, entangled wires, and other structural components.

According to sources, this critical step culminated in the safe removal and dragging out of the rig substructure, thereby creating clear access to the wellhead and enabling preparations for the upcoming snubbing operation, an essential part of the final well control process.

Arrangements for the deployment of snub lines and other preparatory activities are now underway. This phase will include the careful removal of the existing Blowout Preventer (BOP), followed by the installation of a replacement unit as part of the well-capping strategy, the sources said.

They said that in a carefully planned and precisely executed operation, ONGC successfully connected hydraulic lines to the existing BOP to pressurise the unit and operate the rams.

The fact that this was accomplished without any visible increase in gas discharge stands as a strong validation of ONGC's technical assessment and strategic foresight. The operation unfolded exactly as anticipated, reflecting the depth of planning, accurate pressure analysis, and the disciplined execution that have guided ONGC's well control efforts throughout.

Adding to the momentum, favourable weather conditions throughout the day enabled the teams to maximise their productivity. The ONGC team worked in close coordination to leverage the dry weather window and execute key tasks with high efficiency.

In another positive development, the Dikhow River has shown a receding trend, reducing the immediate threat of flooding and supporting site accessibility and logistics, the sources added.

A corporation official earlier said that during servicing operations at Well No. RDS-147A on June 12 morning, an oil well of the ONGC's Rudrasagar field in Sivasagar district, Assam, gushes of gas were observed from the well. The company earlier had said that air quality monitoring continues uninterrupted in and around the site.

'Encouragingly, there is no detectable trace of hydrocarbons beyond 30 metres from the well. Based on current assessments, residents living beyond a 500-metre radius from the incident site have now been advised that it is safe to return to their homes and resume normal activities, including cooking and the use of electricity,' the ONGC had said.

More than 330 families from surrounding villages were evacuated following the gas blowout and are being supported with basic relief and safety measures at a camp set up in nearby Bangaon.

/IANS