Jade Gas Holdings has provided an update on results to date from its six well drilling programme, including information on the drilling of wells Red Lake-2, -3 and -4 in the central core area of the company’s coal bed methane (CBM) gas project over the production sharing agreement area of the Tavantolgoi XXXIII unconventional gas basin in Mongolia (TTCBM project).
- 98% methane identified in Red Lake-1 coal seam III.
- 92.5% methane identified in Red Lake-1 coal seam IV.
- 11 – 15 m3/t of dry ash-free gas content recorded.
- Red Lake-2: reached total depth at 790 m; 46.8 m of gas bearing coal intersected.
- Red Lake-3: preparing for coring at 470 m.
- Red Lake-4: at 863 m; 65.3 m of gas bearing coal intersected.
Jade is targeting natural gas from three coal seams of interest (IV, III and 0) at the TTCBM Project, which has an independently assessed prospective resource of 1 trillion ft3 of gas.
Jade CEO, Chris Jamieson, said: “These results are in line and better than what has been delivered at a number of commercial fields in Australia, whether they be conventional or unconventional. The gas composition of up to 98% methane is outstanding and will make for simple processing of gas should it be produced in offtake quantities.
“It was pleasing that we were able to work with lab technicians at the University of Mongolia in Ulaanbaatar to undertake compositional analysis and equip them to correct for air contamination, which is common in low pressure samples associated with coal bed methane evaluation. As a result, we will look to the University for more compositional analysis from the remaining wells in the programme.
“We are also extremely pleased to see gas content levels of up to 15 m3/t over the coal seams of interest on a dry ash-free basis. This high gas content and the thick coal seams intersected provide a favourable foundation for the TTCBM Project and we look forward to combining these results with those from our testing program as we move toward a contingent resource booking.
“Our drilling programme is on track to be completed in mid-May, with the spudding of Red Lake-5 expected over the coming weeks and Red Lake-6 by mid-April. After these wells have been evaluated and cased, we will then look to undertake an extended production test of Red Lake-5, and possibly Red Lake-6.”
Gas content and composition
Strong results have been delivered from Red Lake-1 in the form of gas composition and gas content. The gas content determination work was undertaken on site by local staff under instruction and review by ALS in Australia. Compositional analysis was completed at the University of Mongolia in Ulaanbaatar.
Numerous gas samples from the thick seam IV in Red Lake-1 delivered consistent gas compositions of 92.5% methane and 7.5% carbon dioxide. Compositional samples from seam III, the highest gas content seam intersected by the well, indicate methane at approximately 98%. Gas compositional analysis for samples recently collected in Red Lake-2 and -4 will commence shortly to further validate the composition across the Red Lake field area.
Gas content from coal seams IV, II and 0 in Red Lake-1 have averaged between 11 – 15 m3/t (dry ash-free basis), a level consistent or better than many commercial CBM fields around the world, including those in the Bowen and Surat CBM basins in Queensland. Gas content measurements from core recovered from Red Lake-2 and -4 is ongoing.
Red Lake-2 is located approximately 2.5 km west of Red Lake-1 and was spudded on 6 February 2022. The well reached total depth (TD) at 790 m, with 46.8 m of gas bearing coal intersected in the coal seams of interest. Red Lake-1 intersected 58 m of gas bearing coal, and with similar sized gas bearing coal seams intersected in Red Lake-2 and -4, the company now has a clearer picture of the consistent size and reach of the coal seams in the Red Lake area.
A drill stem test (DST) interval was recently completed over coal seam 0 at between 749 – 776 m, which was followed by an injection fall off test (IFOT). The results of these tests will be compared against the DST results from Red Lake-1 and the upcoming DST results from Red Lake-5 and -6 to gauge initial permeability estimates over the core area currently being drilled.
The redrill of the Red Lake-3 well is located approximately 3.5 km west of Red Lake-1 and has been drilled to 470 m. At the conclusion of testing at Red Lake-2, the rig will move onto the Red Lake-3 well and core to TD, which is expected to be approximately 725 m.
Red Lake-4 is located approximately 1.5 km south-east of Red Lake-1 and is currently at a depth of 863 m. The IFOT may be run in this well to test permeability through the coal seams of interest at depths of between 700 – 900 m.
Red Lake-5 and -6
The final two wells in the programme, Red Lake-5 and -6, will be drilled as 6 in. wells (wider than Red Lake -1, -2, -3 and -4 which were 4 in. wells) with 4.5 in. casing to be inserted in each well in preparation for the extended production test in 2H22.
On-penetration DSTs will be run in Red Lake-5 and -6 to evaluate the permeability of the coal seams. Red Lake-5 seam 0 will be left open hole with the intention to conduct an extended production test (expected to take between 90 and 180 days) later in 2022. Red Lake-6 will be fully cased and evaluated for potential extended testing in parallel with Red Lake-5, or for use as an initial production well in a future pilot in 2023, dependent on well results.
Read the article online at: https://www.worldcoal.com/cbm/18032022/jade-gas-holdings-provides-ttcbm-update/