Title: Experimental study and application of rock electrical properties under high temperature and high pressure based on Archie's formula: a case study of Jimsar shale oil reservoir in Xinjiang, China

Authors: Xing Zhang; Jiajia Feng; Chun Yin; Meng Feng; Li You; Songsong Huang; Jian Li

Addresses: China University of Petroleum (Beijing) at Karamay, 834000 Karamay, China ' CNPC Xibu Drilling Engineering Company Limited, 834000 Karamay, China ' Xinjiang Oilfield Administrative Affairs Center, 834000 Karamay, China ' CNPC Xibu Drilling Engineering Company Limited, 834000 Karamay, China ' College of Petroleum Engineering, China University of Petroleum (Beijing), 834000 Karamay, China ' College of Petroleum, China University of Petroleum (Beijing) at Karamay, 834000 Karamay, China ' College of Petroleum, China University of Petroleum (Beijing) at Karamay, 834000 Karamay, China

Abstract: This study conducted rock electrical experiments under high temperature and high-pressure conditions, combined with high-pressure mercury injection and nuclear magnetic resonance experiments to analyse the response characteristics of rock electrical parameters in shale oil reservoirs. The saturation index 'n' is positively correlated with increasing porosity and oil saturation, exponentially correlated with permeability logarithm, and negatively correlated with displacement pressure, according to experimental data. The formation factor decreases with porosity, permeability, average capillary radius, and pore throat homogeneity coefficient. Based on saturation index, formation factors, storage and seepage characteristics, and pore-throat structure, permeability and effective porosity were introduced, and two saturation correction models for high temperature and high-pressure rock electrical parameters were created. The model's general applicability shows that it calculates saturation more accurately than Archie's formula, with only 5% average difference from oil saturation. This study provides a more accurate and effective method for shale oil reservoir saturation interpretation. [Received: March 30, 2024; Accepted: August 16, 2024]

Keywords: shale pore throat structure; rock electricity experiment; Archie's equation; saturation correction model; HPMI; NMR; China.

DOI: 10.1504/IJOGCT.2025.147318

International Journal of Oil, Gas and Coal Technology, 2025 Vol.38 No.1, pp.109 - 133

Received: 19 Mar 2024
Accepted: 16 Aug 2024
Published online: 14 Jul 2025 *

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