TMK smashes gas flow records as Mongolian drilling gears up

TMK Energy has lifted gas production to a new monthly record at its 100 per cent-owned Gurvantes XXXV coal seam gas (CSG) project in Mongolia, adding momentum as two rigs prepare to return to the South Gobi field.

September’s average output climbed eight per cent from August to 872 cubic metres a day, equivalent to 30,800 standard cubic feet per day (scfd). The final week averaged 33,400scfd, more than 300 per cent above the level recorded when the company introduced its revised reservoir management plan in August 2025.

The revised plan used slower, less aggressive pumping to reduce coal fines, protect pumps and wells and steadily lower reservoir pressure.

At the LF-07 well, this exact approach produced a stronger gas response, with no pump blockages reported for 14 months while gas production increased and water output remained stable. The company says the technique has lifted production quickly and improved well economics, with lessons applicable to new wells during appraisal and development.

The increase is emerging across multiple wells, not just a single star performer such as LF-07, the pilot’s standout well. TMK says the response indicates gas is desorbing deeper and farther from the wellbores into the coal reservoir, with output continuing through short power interruptions even when pumps were not running.

Producing methane from CSG is a bit like wringing out a wet sponge because the gas is adsorbed onto the surface of underground coal seams and held in place by water pressure. Companies must pump water from fractures until reservoir pressure drops below a critical point, releasing the gas and allowing it to flow to the surface.

September water production remained relatively stable at 425 barrels a day, alongside only occasional brief power interruptions. The combination of rising gas rates and reliable well behaviour is giving management greater confidence in the reservoir’s commercial potential.

The results show we now better understand the coals and how to produce them, with gas production increasing and water production remaining relatively stable. These learnings will guide the future development of the field, reducing the lead time to reach commercial gas flows from new wells.

The 2026 work program, modified in July to test new drilling and lower-cost re-completions, is moving into the field. A workover rig is being mobilised to re-complete an idle existing production well, while the drilling rig is undergoing repairs at contractor Major Drilling’s yard in Ulaanbaatar before tackling a new production well.

The company says the contractor is completing an oil refinery job elsewhere in Mongolia while continuing TMK’s contracted work. Mobilisation is expected in the coming weeks once repairs are complete and the workover rig has departed. Border delays have held up long-lead equipment, with the remaining items expected on site in mid-October.

Together, the rigs will test whether low-cost workovers can lift output from existing wells while optimising the new well’s drilling and completion. Management says the revised scope requires less capital and will guide investment in a full-field development.

TMK’s Gurvantes pilot sits less than 20km from China, one of the world’s largest energy markets, and close to mining operations needing industrial power. The 8400-square-kilometre project hosts an independently certified 2C contingent resource of 1.2 trillion cubic feet (Tcf) across 60 square kilometres. Although the classification covers gas considered potentially recoverable, further work is still required for appraisal and development, alongside 5.3Tcf of best-estimate prospective resource across the wider area.

The pilot must prove production can be repeated and monetised. A proposed 1-megawatt gas-to-power project with Mongolian partner Dashvaanjil Group - feeding off TMK’s gas - could supply the company’s operational power needs and nearby industrial users, with a final investment decision targeted before the end of October, subject to commercial arrangements.

Management says recent meetings with Mongolia’s Mineral Resources and Petroleum Authority and potential gas offtake partners have reinforced the government’s desire to build a CSG industry and strengthen energy security. In a mining district where dependable power is valuable, the project could give rising gas a practical first market while the larger field takes shape.

With production climbing, the workover and drilling campaigns about to begin and an early commercialisation decision just weeks away, TMK is testing whether its improved reservoir recipe can travel beyond one standout well. It appears to be methodically assembling the pieces needed to unlock its giant Mongolian gas prize.

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