Work

Micro–Nano 3D CT Scanning to Assess the Impact of Microparameters of Volcanic Reservoirs on Gas Migration

Year: 2024

Type: article

Abstract: Volcanic hydrocarbon reservoirs have been studied extensively worldwide. Owing to the significant heterogeneity of these reservoirs, micropores and fractures play crucial roles in controlling the storage and transportation of natural gas. By establishing a pore-fracture model at the micro-nano scale, it is possible to systematically identify the control parameters and transport mechanisms of natural gas in volcanic reservoirs. Based on micro-nano-CT scanning technology, a comparative study was conducted on samples of the CS1 well (rhyolitic debris-crystal welded tuff) from the Changling fault depression and W21 well (quartz crystalline tuff well) from the Wangfu fault depression, with a lithology similar to that of the Yingcheng Formation in the southern Songliao Basin, China. Using the Avizo software, the 3D digital cores were reconstructed, models for 3D total pore distribution, 3D connected pore segmentation, pore-throat network, and 3D fracture body were established. For these relevant pore models, isolated pores were initially eliminated, and a statistical analysis of the pore-throat structural parameters was conducted. For the fracture body model, the fracture morphology and characteristics of dissolution channels within the fractures were discussed from various angles. Through microscale gas seepage simulations, the seepage paths were demonstrated, and the correlation between the permeability and micropore-throat parameters was analysed. The results show that the fundamental storage and transport of natural gas are determined by the volume and surface area of the connected pores, the length and radius of the throat, and the coordination number. The development of the fractures not only promotes the connection of primary pores but also results in the formation of numerous secondary pores through their dissolution, significantly increasing the reservoir space. The seepage phenomenon of natural gas is most obvious during the development of fractures, and the throat radius in the pore-throat parameters contributes the most to permeability, followed by the pore radius.

Source: Processes

DOI: 10.3390/pr12092000

Authors: Xiangwei Gao, Yunliang Yu, Zhongjie Xu, Yingchun Liu, Panpan Zang

Institution: Jilin University

Language: English

Topic: Hydrocarbon exploration and reservoir analysis

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,728

Funders: National Natural Science Foundation of China, China National Petroleum Corporation