The characteristics of hydrocarbon generation, reserving performances of fine-grained rock, and preservation conditions of coal measure shale gas of an epicontinental sea basin: A case study of the Late Palaeozoic shale gas in the Huanghebei Area of Western Shandong

Abstract

In China, marine and land transitional fine-grained rocks (shale, mudstone, and so on) are widely distributed and are known to have large accumulated thicknesses. However, shale gas explorations of these types of rock have only recently been initiated, thus the research degree is very low. Therefore, this study was conducted in order to improve the research data regarding the gas accumulation theory of marine and continental transitional fine-grained rock, as well as investigate the shale gas generation potential in the Late Paleozoic fine-grained rock masses located in the Huanghebei Area of western Shandong Province. The hydrocarbon generation characteristics of the epicontinental sea coal measures were examined using sedimentology, petrography, geochemistry, oil and gas geology, tectonics, and combined experimental testing processes. The thick

Coexistence and Development Model of Multi-Minerals Dominated by Multilayer Magma Intrusion

“…The eastern part of the coalfield is the boundary between the Woniushan fault and Zhangqiu Coalfield, whereas the western part is the Liuji fault adjacent to the Yanggu-Chipping Coalfield. The southern part is the outcrop of the coal measure bottom, and the northern part is the Qiguang fault which is rich in coal resources (Li et al [9]). Affected by the long-term uplift of the Luzhong Block uplift, the regional strata in the Huanghebei Coalfield generally show obvious gentle monoclinal structure.…”

“…The Huanghebei Coalfield is located in the North China stratigraphic area-Luxi stratigraphic division, and the coal-bearing rock series are mainly developed in the Carboniferous and Permian followed by The Benxi Formation Taiyuan Formation Shanxi Formation Lower Shihezi Formation and Upper Shihezi Formation from bottom to top (Sun et al [12][13][14]). Only the Heishan Member and the Wanshan Member remain in the Huanghebei Coalfield due to denudation in the sedimentary process (Li et al [9]). The Yanshanian movement has strong activity in this area and formed a structural pattern with fault depression and fault uplift as the main characteristics.…”

“…The coalification of organic matter in coal in geological history, that is, coal rank or thermal maturity, is usually measured by vitrinite reflectance (Smith et [42]). Based on the "Data Measurement Method of Vitrinite Reflectance of Sedimentary Rocks" (SY/T 5124-1995) (Li et al [9] and according to the People's Republic of China Coal Industry Standard Catalog [43], the classification of coal grades is made. At the same time, according to the "Regulation of Shale Gas Resources/Reserves Estimation" (DZ/T 0254-2014), the degree of the thermal evolution of shale gas layers is classified.…”

Effect of lithofacies on pore structure of the Cambrian organic‐rich shale in northern Guizhou, China

“…However, shale gas production from different wells varies enormously because of the intense heterogeneity of reservoir properties (Cho, Apaydin, & Ozkan, 2013; Wang & Marongiu‐Porcu, 2015). Among those reservoir properties, pore structure is the most important one because it determines the preservation and seepage of shale gas (Li, Li, Wang, & Wang, 2019; Ross & Bustin, 2009). As an elementary unit of shale reservoir, shale gas is an overall reflection of mineral composition, organic matter content, texture, structure, and colour of shale reservoir (Abouelresh & Slatt, 2012), and different shale lithofacies have distinct types of pore structure (Yang et al, 2018).…”

Evolution Mechanism of Material Composition–Pore Structure–Adsorption Property in Marine Shale Based on Pyrolysis Experiments: A Typical Case of the Mesoproterozoic Xiamaling Formation

“…The Lower Palaeozoic in southern China is the main target for shale gas exploration and exploitation. Unfortunately, there are still many challenges hindering the large-scale exploitation of shale gas in China. − Among them, China’s complex geological conditions are the core bottleneck restricting commercial exploitation of shale gas. ,− The buried depth of shale gas reservoirs in the United States ranges primarily from 350 to 4500 m, with a maturity ( R o ) ranging from 1.0% to 2.5% (in the middle- and high-maturity stages). , By comparison, Lower Palaeozoic marine shale reservoirs in southern China are 1000–6000 m deep, with their maturity ranging from the high to overmaturity stage ( R o = 2.5%–4.5%) . Therefore, the evolution process of shale material composition, pore structure, and adsorption properties is more complicated. − …”