Open Access

ARTICLE

Investigation of Electrical Parameters of Fresh Water and Produced Mixed Injection in High-Salinity Reservoirs

Jun Li¹, Guofeng Cheng², Hongwei Xiao³, Xiang Li⁴, Lizhi Wang⁴, Hui Xu^5,*, Yu Wang⁶, Nannan Liu⁵, Shangping Chen⁵, Xing Shi⁵

1 PetroChina Research Institute of Petroleum Exploration & Development, Beijing, 100083, China
2 Changqing Oilfield No.5 Oil Production Plant, PetroChina, Xi’an, 710000, China
3 Exploration and Development Research Institute of Daqing Oilfield Co., Ltd., Daqing, 163712, China
4 Key Laboratory of Shallow Geothermal Energy, Ministry of Natural Resources of the People’s Republic of China, Beijing, 100195, China
5 Jiangsu Key Laboratory of Oil-Gas Storage and Transportation Technology, School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, 213164, China
6 Sinopec International Petroleum Exploration and Production Corporation, Beijing, 100029, China

* Corresponding Author: Hui Xu. Email:

Fluid Dynamics & Materials Processing 2023, 19(10), 2695-2706. https://doi.org/10.32604/fdmp.2023.028115

Received 30 November 2022; Accepted 20 February 2023; Issue published 25 June 2023

Abstract

Assuming a reservoir with a typical salt-lake background in the Qaidam Basin as a testbed, in this study the variation law of the rock electrical parameters has been determined through water displacement experiments with different salinities. As made evident by the results, the saturation index increases with the degree of water injection. When the salinity of the injected water is lower than 80000 ppm, the resistivity of the rock sample first decreases, then it remains almost constant in an intermediate stage, and finally it grows, thereby giving rise to a ‘U’ profile behavior. As the salinity decreases, the water saturation corresponding to the inflection point of the resistivity becomes lower, thereby leading to a wider ‘U’ type range and a higher terminal resistivity. For different samples, higher initial resistivity of the sample in the oil-bearing state, and higher resistivity after low-salinity water washing are obtained when a thicker lithology is considered.

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