Gas trap stability in the Zechstein Limestone from the Rudna Copper Mine (SW Poland)

Abstract

A gas and crashed rock burst in 2009 in the Rudna Copper Mine was the motivation to re-investigate the dolomite succession of the first Permian cyclothem (Werra), which covers the ceiling section of the excavations. Gas traps were recognized by previous research; however, the stability of gas traps during mining operations has not been studied yet. Mitigation of future gas bursts requires a complex analysis of these gas traps, involving petrological, petrophysical and mechanical analysis of the reservoir dolomite facies. The results indicate the significant influence of dolomite texture, porosity and extent of late diagenetic dolomite cement on the reservoir and geomechanical properties, and the induced failure pattern of the dolomite facies. The mechanism of dolomite failure allowed for interpreting the degree of dolomite degassing during and after mining operations.

Tracking Deformation Processes at the Legnica Glogow Copper District (Poland) by Satellite InSAR—I: Room and Pillar Mine District

“…The tectonic units that occur in the mining area are represented by: (i) the Proterozoic-Palaeozoic metamorphic basement, (ii) the Permo-Triassic complex of sedimentary rocks, which is smoothly dipping to the NE, and above the latter, and (iii) a more or less horizontal Cenozoic sediments sequence [32]. The copper ore deposits belong to the Permo-Triassic complex of sedimentary rocks and in particular to the Kupferschiefer Formation and to the basal part of the Zechstein Limestone, and the mines are localized at the boundary between the platform and the basin facies of the Zechstein Limestone ( [33]; Figure 2a,b).…”

“…Land 2021, 10, x FOR PEER REVIEW 4 of 22 rocks, which is smoothly dipping to the NE, and above the latter, and (iii) a more or less horizontal Cenozoic sediments sequence [32]. The copper ore deposits belong to the Permo-Triassic complex of sedimentary rocks and in particular to the Kupferschiefer Formation and to the basal part of the Zechstein Limestone, and the mines are localized at the boundary between the platform and the basin facies of the Zechstein Limestone ( [33]; Figure 2a,b). Stratiform mineralization founded within sandstones, shales, and dolomites, occurs in different amounts from mine to mine and is located at depths between 600 m and 1200 m (www.mining-technology.com, accessed on 15 May 2021).…”

“…Figure 2. Geological setting of the study area; (a) tectonic sketch (modified from [21]); Zechstein limestones belong to Lower and Upper Permian deposits in the legend; (b) schematic geological section of the Rudna Copper Mine (modified from[33]). …”

Origin Type and Generating Mechanism of Coal Measure Limestone Gas: A Case Study of L1 Limestone Gas in the Taiyuan Formation of the Shenzhou Coal Mine, Eastern Edge of the Ordos Basin, China

“…The degrees and types of the reservoir space are the key factors which affect the characteristics of accumulation and flowage for oil and gas . The fractured-vuggy carbonate reservoirs constitute over 60% of the carbonate reservoirs. , The containing vugs and fractures with various scales in the carbonate reservoirs are the primary reserving space of natural gas. , Over the course of the study for gas prevention and control in the coal mine, the limestone gas enrichment space in the roof or floor of the coal seam is also the fractures and small caves caused by the geological structure and hydrogeological conditions…”