Enrichment Characteristics and Technical Strategies for Development of Natural Gas: A Case Study of the Mizhi–Qingjian Block in the Ordos Basin

The eastern Ordos Basin holds substantial natural gas resources, yet its development performance varies considerably across different areas, and the underlying causes merit close attention. Taking the Mizhi–Qingjian Block as a case study, this paper integrated petrophysical tests, well-logging interpretation, and volumetric resource estimation to characterize the development of TSM (tight sandstone methane) and deep CBM (coalbed methane) reservoirs in the BX Fm (Benxi Formation) to H8 Mb (He 8 Member) interval. The results indicate that the H8 Mb effective sandstones exhibit the best reservoir development. The No. 8 coal seam is markedly thicker than the No. 5 coal seam. Water-bearing zones are extensively distributed in the Qingjian Block. Resource potential assessment shows that the TSM resources in the BX Fm–H8 Mb interval total 1962.72 × 108 m3, of which Class I + II amount to 905.47 × 108 m3. The deep CBM resources of the No. 5 and No. 8 coal seams together reach 9974.31 × 108 m3, with Class I + II accounting for 5503.83 × 108 m3. On this basis, a synergistic co-production technology has been developed to enable efficient and coordinated extraction of both TSM and deep CBM resources. Northern Mizhi is identified as the primary development target, while the Qingjian area requires cautious planning due to high water content.