Geological features and exploration fields of tight oil in the Cenozoic of western Qaidam Basin, NW China

Liu, Zhan‐Guo; Zhu, Chao; Li, Senming; Xue, Jinbo; Gong, Quanmei; Wang, Yanqing; Wang, Peng; Xia, Zhiyuan; Song, Guoqi

doi:10.1016/s1876-3804(17)30024-1

Cited by 30 publications

(4 citation statements)

References 4 publications

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“…Therefore, ground deformation monitoring and reservoir parameter inversion in oil extraction areas are essential for ensuring the safety of oilfields. The Qaidam Basin, often referred to as China's "treasure trove", is not only abundant in various mineral resources but also hosts important oil and gas accumulation zones in its western region [6,7]. By the year 2020, the Qaidam Basin boasted 32 identified oil and gas fields, with combined proven reserves exceeding 6.4 billion tons [8,9].…”

Section: Introductionmentioning

confidence: 99%

Oilfield Reservoir Parameter Inversion Based on 2D Ground Deformation Measurements Acquired by a Time-Series MSBAS-InSAR Method

Liu,

Zhang,

Yang

et al. 2023

Remote Sensing

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Time-series ground deformation monitoring and reservoir parameter inversion are crucial for the dynamic assessment of oilfield resources and sustainable exploitation in oilfields. As some of the regions with the richest oil reserves in China, the oilfield areas in the western Qaidam Basin were selected as a typical study area. Firstly, we used SAR images collected by the Sentinel-1A satellite from January 2021 to December 2022 and applied the multidimensional small baseline subset (MSBAS) method to obtain vertical and east–west deformation measurements. On this basis, a nonlinear Bayesian inversion method was applied to model the shallow reservoir in a series of complex deformation areas, based on a single-source model and a multi-source model, respectively. As a result, the ground deformation monitoring results obtained by long time-series InSAR clearly reflect the uneven ground deformation caused by the oil extraction and water injection operation processes. There was slight subsidence in the Huatugou oilfield, while significant uplift deformation occurred in the Ganchaigou oilfield and the Youshashan oilfield, with a maximum uplift rate of 48 mm/year. Further analysis indicated that the introduction of the 2D deformation field helps to improve the robustness of oilfield reservoir parameter inversion. Moreover, the dual-source model is more suitable than the single-source model for inverting reservoir parameters of complex deformation. This study not only fills the gap of InSAR deformation monitoring for the oilfields in the western Qaidam Basin but also provides a theoretical reference for the model and method selection of reservoir parameter inversion in other oilfields.

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Section: Introductionmentioning

confidence: 99%

Oilfield Reservoir Parameter Inversion Based on 2D Ground Deformation Measurements Acquired by a Time-Series MSBAS-InSAR Method

Liu,

Zhang,

Yang

et al. 2023

Remote Sensing

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“…2 ), the area, on an overall basis, successively experiences three complete sedimentary evolution stages of the saline lacustrine basin, namely, semi-salinization, salinization, and salt lake, under the arid paleo-climate [25][26][27][28]. During the semi-salinization stage, the sediment supply is sufficient, the salinity is low, the lake level is relatively high, and the deposited sediments are mainly limy claystone, based on well core observations.…”

Section: Methodsmentioning

confidence: 99%

Lithofacies Characteristics and Methodology to Identify Lacustrine Carbonate Rocks via Log Data: A Case Study in the Yingxi Area, Qaidam Basin

Tian,

Liu,

Zhu

et al. 2023

Energies

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Lacustrine carbonate reservoirs, extensively distributed in China, have extensive oil and gas exploration potential. However, such reservoirs are characterized by high content of terrigenous debris and complex lithofacies, and the resultant high difficulty in lithofacies identification severely restrains exploration expansion and efficient development, especially for the Upper Member of the Paleogene Lower Ganchaigou Formation (E32) of the Yingxi area in the Qaidam Basin, with burial depths generally greater than 4000 m. This research targets this area and develops a methodology for detailed lithofacies identification, after systematically investigating the characteristics of lithofacies and well log responses of lacustrine carbonate rocks, on the basis of a massive volume of data of cores, thin sections, and experiments of the study area. The analysis identified lithofacies in the Upper Member of the Paleogene Lower Ganchaigou Formation of the Yingxi area, namely, pack-wackestone, mudstone, laminated carbonate, muddy gypsum, and limy claystone. The analysis of well log response characteristics suggested that natural gamma ray, matrix density, and bulk density were sensitive to lithofacies. Then, for the first time, the rock fabric factor (RFF) method was proposed, and the lithofacies identification plot was based on the calculated RFF and high-definition spectroscopy log. The presented methodology was applied to 55 wells in the study area. The average accuracy of lithofacies interpretation in 14 cored wells reached 82.4%, indicating good application performance. This method improves the lithofacies identification accuracy of lacustrine carbonate rocks, which is of great significance for investigating the reservoir distribution law and guiding exploration and development.

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“…Influenced by the difference in tectonic compression during different periods, this area exhibited distinct paleotopographical characteristics with alternating uplifted and subsided regions. Therefore, in the whole sedimentary environment of semi-deep to shallow lake subfacies, microfacies types such as gypsum pans, sandy shoals, saline lakes, and muddy dolomitic semi-deep lakes can be observed [32] (Figure 1b).…”

Section: Geological Settingsmentioning

confidence: 99%

High-Frequency Lacustrine Lithological and Geochemical Variations in the Eocene Qaidam Basin: Implications for Paleoenvironment Reconstruction

Wu,

Tan,

Liu

et al. 2024

Minerals

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Lacustrine sedimentary processes exhibit high sensitivity to paleoenvironmental changes, often manifesting as high-frequency sedimentary cycles that control the complex variations in sedimentary structure, mineral composition, and element distribution. However, the intricate co-variation mechanism among paleoclimate and paleowater properties at a high precision level (centimeter to meter scale) is still controversial. This study focuses on conducting a high-frequency cycle analysis of lacustrine mixed rocks from the Eocene Lower Ganchaigou Formation (LGCG) in the Qaidam Basin, employing petrology, mineralogy, organic geochemistry, and elemental geochemistry techniques. The lithological variation was characterized by the superposition of three lithofacies types from the bottom to the top with a single sequence: massive sandstone, laminated silty shale, and bedded calcareous dolostone. Geochemical data revealed cyclical variations in the paleoenvironment in the vertical profile, which conformed to the high-frequency lithofacies cycles. Based on the reconstruction of the lake level and paleowater properties, a synthesized paleoclimate–sedimentary model that comprised three consecutive periods within an individual sequence was established. From the bottom to the top of each cycle, the Eocene paleoenvironment varied from reduction and desalination to oxidation and salinization, which was controlled by a decline in the lake level resulting from a transformation of the paleoclimate from warm and humid to cold and arid. The variations in petrology and geochemistry observed in the Eocene Qaidam Basin play a crucial role in comprehending the sedimentary response to paleoenvironmental changes at high precision levels within lacustrine settings.

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Geological features and exploration fields of tight oil in the Cenozoic of western Qaidam Basin, NW China

Cited by 30 publications

References 4 publications

Oilfield Reservoir Parameter Inversion Based on 2D Ground Deformation Measurements Acquired by a Time-Series MSBAS-InSAR Method

Oilfield Reservoir Parameter Inversion Based on 2D Ground Deformation Measurements Acquired by a Time-Series MSBAS-InSAR Method

Lithofacies Characteristics and Methodology to Identify Lacustrine Carbonate Rocks via Log Data: A Case Study in the Yingxi Area, Qaidam Basin

High-Frequency Lacustrine Lithological and Geochemical Variations in the Eocene Qaidam Basin: Implications for Paleoenvironment Reconstruction

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