ZHANG H, XIAO D S, CHEN X , et al.Characteristics of deep coal reservoirs and exploration potential of coal-measure gas in Turpan-Hami Basin[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(1):29-39.

doi:10.16186/j.cnki.1673-9787.2025050012

Received:2025/05/17

Revised:2025/07/23

Published:2025-12-03

Characteristics of deep coal reservoirs and exploration potential of coal-measure gas in Turpan-Hami Basin

Zhang Hua1,2, Xiao Dongsheng1, Chen Xuan1, Wu Chao1, Cheng Yi1, Wureyimu Kesar1

1.Research Institute of Exploration & Development， PetroChina Tuha Oilfield Company， Hami  839009， Xinjiang， China；2.Xinjiang Research Institute， Huairou Laboratory， Urumqi  830000， Xinjiang， China

Abstract: Objectives Taddress insufficient geological understanding of deep coal-measure gas exploration in the Turpan-Hami（Tuha）Basin， this study focuses on well K1—the deep coal-measure gas well—systematically investigating its coal reservoir characteristics and exploration potential. The aim is to reveal the gas occurrence patterns and accumulation models in deep coal measures， providing a scientific basis for large-scale exploration and development. Methods Coal petrographic analysis， three-dimensional CT scanning， overburden pressure porosity-permeability experiments， and isothermal adsorption tests are conducted. Parameters such as coal maceral composition， pore structure， and dynamic permeability changes are integrated for a comprehensive analysis of the reservoir physical properties. Geological conditions of the Junggar and Ordos Basins are compared， and logging data combined with coalbed methane resource prediction methods are used to evaluate the exploration potential of deep coal-measure gas in the Tuha Basin. Results Deep coal reservoirs in the Tuha Basin are predominantly low- to medium-rank coals（K1 well： R_o =0.64%~0.94%）， with vitrinite content up to 80.96%. The coal exhibits intact yet soft structures， characterized by “low porosity， low permeability， and complex pore structures.” Porosity ranges from 2.99% to 7.55%， and permeability varies from 0.044×10-3 to 13.52×10-3 μm2， both decreasing with depth. The reservoirs demonstrate a dual-phase gas storage mechanism of “microporous adsorption + macroporous/fracture free gas.” Field gas content tests indicate a total gas content of 14.24 to 18.23 cm3/g in the main coal seams， with free gas accounting for 35%~40%. The desorption rates are rapid （adsorption times ranging from 4.06 to 5.01 days）， demonstrating a “coexisting dual-phase， free gas-dominated” storage advantage. Two reservoir formation models are identified： （1） the northern piedmont “adjustment-type” gas reservoir and （2） the central sag “self-sourced and self-reservoired” gas reservoir. Compared to the Junggar and Ordos Basins， the Tuha Basin exhibits moderate thermal evolution， high free gas ratios，and rapid initial production efficiency. Conclusions The deep coal-measure gas in the Tuha Basin shows significant exploration potential. The main coal seams in the Taibei Sag （Xishanyao Formation） contain resources reserves exceeding 2.2 trillion m3. The Wenjisang structural belt and Xiaocao South Slope emerge as prioritized exploration targets due to their “high free gas ratios and low desorption resistance.”

Key words:deep coal reservoir;coal-measure gas;exploration potential;gas occurrence characteristics