Title: Pore characteristics and its impact factors of shale from the Upper Cambrian Niutitang formation in the Southern Shaanxi area, China

Authors: Yuanzhe Peng; Xiaowei Ma; Junfeng Zhang; Jinyan Xie; Xiaona Zhang; Zhao Yan; Junlin Chen

Addresses: State Key Lab Continental Dynam., Department of Geology, Northwest University, China; Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Shaanxi Min Ind and Trade Co Ltd., Xian 710000, China ' Key Laboratory of Petroleum Resources, Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China; University of Chinese Academy of Sciences, Beijing 100049, China

Abstract: The pore network in shale could influence the proportion of adsorbed gases and total gas content and thus is significantly important for the exploration and development of shale gas. The Lower Cambrian Niutitang Formation shale has been proved that have impressive shale gas exploration prospect. Ten Niutitang Formation shale samples were collected from the Micangshan-Hannan Uplift of the Southern Shaanxi area. The TOC is between 0.68% to 2.51%, averaging at 1.54%, and the mineral compositions are dominated by quartz, feldspar, and clay. The pore types comprise intergranular pore, inter-crystalline pore in clay matrix and pyrite aggregates, and organic pore. Quantitative pore structure investigation and impact factors were conducted. The pore area and pore volume are mainly contributed by macropores and mesopores, respectively. TOC, quartz and carbonate contents can jointly influence the pore space. The development of micropore in shale samples is closely related to organic matter, and which is associate with the content of quartz. [Received: November 30, 2023; Accepted: March 30, 2024]

Keywords: pore structure; upper Cambrian Niutitang formation; Southern Shaanxi area; influencing factor.

DOI: 10.1504/IJOGCT.2024.140918

International Journal of Oil, Gas and Coal Technology, 2024 Vol.36 No.3, pp.312 - 327

Received: 26 Nov 2023
Accepted: 30 Mar 2024
Published online: 03 Sep 2024 *

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