Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin

The tight sandstone reservoirs in the first sub-member of Chang 7 member (Chang 71) of Triassic Yanchang Formation in the Jiyuan area, Ordos Basin, show significant variations in microscopic pore-throat structure (PTS) and fluid mobility due to the influences of the northeast and northwest dual prov...

Full description

Saved in:
Bibliographic Details
Main Authors: Quanpei Zhang, Chen Yang, Ye Gu, Yu Tian, Hui Liu, Wen Xiao, Zhikun Wang, Zhongrong Mi
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2025-06-01
Series:Energy Geoscience
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666759225000289
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849330910859624448
author Quanpei Zhang
Chen Yang
Ye Gu
Yu Tian
Hui Liu
Wen Xiao
Zhikun Wang
Zhongrong Mi
author_facet Quanpei Zhang
Chen Yang
Ye Gu
Yu Tian
Hui Liu
Wen Xiao
Zhikun Wang
Zhongrong Mi
author_sort Quanpei Zhang
collection DOAJ
description The tight sandstone reservoirs in the first sub-member of Chang 7 member (Chang 71) of Triassic Yanchang Formation in the Jiyuan area, Ordos Basin, show significant variations in microscopic pore-throat structure (PTS) and fluid mobility due to the influences of the northeast and northwest dual provenance systems. This study performed multiple experimental analyses on nine samples from the area to determine the petrological and petrophysical properties, as well as the PTS characteristics of reservoirs in different provenance-controlled regions. On this basis, the pore-throat size distribution (PSD) obtained from high-pressure mercury injection (HPMI) was utilized to convert the NMR movable fluid T2 spectrum, allowing for quantitative characterization of the full PSD and the occurrence characteristics of movable fluids. A systematic analysis was conducted on the primary controlling factors affecting fluid mobility in the reservoir. The results indicated that the lithology in the eastern and western regions is lithic arkose. The eastern sandstones, being farther from the provenance, exhibit higher contents of feldspar and lithic fragments, along with the development of more dissolution pores. The reservoir possesses good petrophysical properties, low displacement pressure, and high pore-throat connectivity and homogeneity, indicating strong fluid mobility. In contrast, the western sandstones, being nearer to the provenance, exhibit poor grain sorting, high contents of lithic fragments, strong compaction and cementation effects, resulting in poor petrophysical properties, and strong pore-throat heterogeneity, revealing weak fluid mobility. The range of full PSD in the eastern reservoir is wider than that in the western reservoir, with relatively well-developed macropores. The macropores are the primary space for occurrence of movable fluids, and controls the fluid mobility of the reservoir. The effective porosity of movable fluids (EPMF) quantitatively represents the pore space occupied by movable fluids within the reservoir and correlates well with porosity, permeability, and PTS parameters, making it a valuable parameter for evaluating fluid mobility. Under the multi-provenance system, the eastern and western reservoirs underwent different sedimentation and diagenesis processes, resulting in differential distribution of reservoir mineral components and pore types, which in turn affects the PTS heterogeneity and reservoir quality. The composition and content of reservoir minerals are intrinsic factors influencing fluid mobility, while the microscopic PTS is the primary factor controlling it. Low clay mineral content, well-developed macropores, and weak pore-throat heterogeneity all contribute to the storage and seepage of reservoir fluids.
format Article
id doaj-art-e2d49c2c4dbe40d0b6c7500ce171217b
institution Kabale University
issn 2666-7592
language English
publishDate 2025-06-01
publisher KeAi Communications Co., Ltd.
record_format Article
series Energy Geoscience
spelling doaj-art-e2d49c2c4dbe40d0b6c7500ce171217b2025-08-20T03:46:46ZengKeAi Communications Co., Ltd.Energy Geoscience2666-75922025-06-016210040710.1016/j.engeos.2025.100407Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos BasinQuanpei Zhang0Chen Yang1Ye Gu2Yu Tian3Hui Liu4Wen Xiao5Zhikun Wang6Zhongrong Mi7China ZhenHua Oil Co., Ltd., Beijing, 100031, China; Corresponding author.Chengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaChengdu Northern Petroleum Exploration and Development Technology Co. Ltd., Chengdu, 610059, ChinaThe tight sandstone reservoirs in the first sub-member of Chang 7 member (Chang 71) of Triassic Yanchang Formation in the Jiyuan area, Ordos Basin, show significant variations in microscopic pore-throat structure (PTS) and fluid mobility due to the influences of the northeast and northwest dual provenance systems. This study performed multiple experimental analyses on nine samples from the area to determine the petrological and petrophysical properties, as well as the PTS characteristics of reservoirs in different provenance-controlled regions. On this basis, the pore-throat size distribution (PSD) obtained from high-pressure mercury injection (HPMI) was utilized to convert the NMR movable fluid T2 spectrum, allowing for quantitative characterization of the full PSD and the occurrence characteristics of movable fluids. A systematic analysis was conducted on the primary controlling factors affecting fluid mobility in the reservoir. The results indicated that the lithology in the eastern and western regions is lithic arkose. The eastern sandstones, being farther from the provenance, exhibit higher contents of feldspar and lithic fragments, along with the development of more dissolution pores. The reservoir possesses good petrophysical properties, low displacement pressure, and high pore-throat connectivity and homogeneity, indicating strong fluid mobility. In contrast, the western sandstones, being nearer to the provenance, exhibit poor grain sorting, high contents of lithic fragments, strong compaction and cementation effects, resulting in poor petrophysical properties, and strong pore-throat heterogeneity, revealing weak fluid mobility. The range of full PSD in the eastern reservoir is wider than that in the western reservoir, with relatively well-developed macropores. The macropores are the primary space for occurrence of movable fluids, and controls the fluid mobility of the reservoir. The effective porosity of movable fluids (EPMF) quantitatively represents the pore space occupied by movable fluids within the reservoir and correlates well with porosity, permeability, and PTS parameters, making it a valuable parameter for evaluating fluid mobility. Under the multi-provenance system, the eastern and western reservoirs underwent different sedimentation and diagenesis processes, resulting in differential distribution of reservoir mineral components and pore types, which in turn affects the PTS heterogeneity and reservoir quality. The composition and content of reservoir minerals are intrinsic factors influencing fluid mobility, while the microscopic PTS is the primary factor controlling it. Low clay mineral content, well-developed macropores, and weak pore-throat heterogeneity all contribute to the storage and seepage of reservoir fluids.http://www.sciencedirect.com/science/article/pii/S2666759225000289Pore-throat structureFluid mobilityTight sandstone reservoirMulti-provenance systemOrdos Basin
spellingShingle Quanpei Zhang
Chen Yang
Ye Gu
Yu Tian
Hui Liu
Wen Xiao
Zhikun Wang
Zhongrong Mi
Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
Energy Geoscience
Pore-throat structure
Fluid mobility
Tight sandstone reservoir
Multi-provenance system
Ordos Basin
title Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
title_full Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
title_fullStr Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
title_full_unstemmed Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
title_short Microscopic pore-throat structure and fluid mobility of tight sandstone reservoirs in multi-provenance systems, Triassic Yanchang formation, Jiyuan area, Ordos Basin
title_sort microscopic pore throat structure and fluid mobility of tight sandstone reservoirs in multi provenance systems triassic yanchang formation jiyuan area ordos basin
topic Pore-throat structure
Fluid mobility
Tight sandstone reservoir
Multi-provenance system
Ordos Basin
url http://www.sciencedirect.com/science/article/pii/S2666759225000289
work_keys_str_mv AT quanpeizhang microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT chenyang microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT yegu microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT yutian microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT huiliu microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT wenxiao microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT zhikunwang microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin
AT zhongrongmi microscopicporethroatstructureandfluidmobilityoftightsandstonereservoirsinmultiprovenancesystemstriassicyanchangformationjiyuanareaordosbasin