Genetic Types and Source of the Upper Paleozoic Tight Gas in the Hangjinqi Area, Northern Ordos Basin, China

Abstract

The molecular and stable isotopic compositions of the Upper Paleozoic tight gas in the Hangjinqi area in northern Ordos Basin were investigated to study the geochemical characteristics. The tight gas is mainly wet with the dryness coefficient (C 1 /C 1-5 ) of 0.853-0.951, and 13 C 1 and 2 H-C 1 values are ranging from −36.2‰ to −32.0‰ and from −199‰ to −174‰, respectively, with generally positive carbon and hydrogen isotopic series. Identification of gas origin indicates that tight gas is mainly coal-type gas, and it has been affected by mixing of oil-type gas in the wells from the Shilijiahan and Gongkahan zones adjacent to the Wulanjilinmiao and Borjianghaizi faults. Gas-source correlation indicates that coal-type gas in the Shiguhao zone displays distalsource accumulation. It was mainly derived from the coal-measure source rocks in the Upper Carboniferous Taiyuan Formation (C 3 t) and Lower Permian Shanxi Formation (P 1 s), probably with a minor contribution from P 1 s coal measures from in situ Shiguhao zone. Natural gas in the Shilijiahan and Gongkahan zones mainly displays near-source accumulation. The coal-type gas component was derived from in situ C 3 t-P 1 s source rocks, whereas the oil-type gas component might be derived from the carbonate rocks in the Lower Ordovician Majiagou Formation (O 1 m).

Evolution Mechanism of Differential Diagenesis Combination and Its Effect on the Reservoir Quality in the Tight Sandstone: A Case from the Lower Shihezi Formation in the Hangjinqi Area of Ordos Basin, China

“…The middle Permian includes the lower Shihezi (P 2 h) and upper Shihezi Formation (P 2 s). The upper Permian comprises Shiqianfeng Formation (P 3 s) [24,25,36] (Figure 2). The lower Shihezi Formation, which mainly consists of tight sandy conglomerates, pebbly coarse-, coarse-, medium-, and fine-grained sandstones, was mainly deposited in fluvial and delta [26,37,38] (Figure 2).…”

“…The Middle Permian lower Shihezi Formation is one of the most important tight gas sandstone reservoirs in the Hangjinqi area of Ordos Basin, China [24,25]. The tight sandstone of the lower Shihezi Formation has generally undergone complicated diagenetic alterations which have reduced the reservoir quality.…”

Identification of Favorable Zones of Gas Accumulation via Fault Distribution and Sedimentary Facies: Insights From Hangjinqi Area, Northern Ordos Basin

“…These incorporate Sulige, Yulin, Changqing, Jinbian, and Daniudi gas fields (Duan et al, 2008;Yang et al, 2015a). Our study is focused on the Hangjinqi area, which is situated in the Yimeng Uplift and northern Yishan slope, covering an area of 9825 km 2 within northern Ordos Basin (Wu et al, 2017) (Figure 1A). In recent times, exploratory wells within the Hangjinqi area found a considerable volume of gas in the sandstones of the Upper Paleozoic era (Xu et al, 2018).…”

“…Numerous faults were established, which made the study area more complicated. Former studies conducted within the study area were focused on the structural evolution (Yang et al, 2015a;Yang et al, 2015b), tectonic controls (Liu et al, 2020), channel identification (Anees et al, 2019;Anees et al, 2022), evaluation of genetic types and source of Upper Paleozoic tight gas (Wu et al, 2017), hydrothermal mineralization of uranium deposits (Zhang et al, 2017), and evaluation of clay mineral content, and type of reservoir properties (Wang et al, 2020).…”

Comparative Study on the Reservoir Characteristics and Development Technologies of Two Typical Karst Weathering-Crust Carbonate Gas Reservoirs in China

“…Among those, the Lower Paleozoic gas reservoir in the Jingbian gas field, Ordos Basin and the Sinian gas reservoir in the Anyue gas field, Sichuan Basin are the most monolithic karst weathering-crust carbonate rock gas reservoirs in China, with the largest proven GIIP. The Jingbian gas field is one of the first large-scale karst weathering-crust carbonate rock gas fields in China that has been discovered and successfully put into development [7,8]. It is one of the main gas fields in Changqing gas area.…”