A novel hybrid method for gas hydrate filling modes identification via digital rock. (May 2020)

• Record Type: Journal Article
• Authors: Dong, Huaimin; Sun, Jianmeng; Arif, Muhammad; Golsanami, Naser; Yan, Weichao; Zhang, Yihuai
• Is Part Of: Marine and petroleum geology. Volume 115(2020)
• Publication Date: 2020-05
• Subjects: Gas hydrate -- Geophysical logs -- Filling modes -- Rock physics -- Gas hydrate saturation -- Saturation exponent; Submarine geology -- Periodicals; Petroleum -- Geology -- Periodicals; Géologie sous-marine -- Périodiques; Pétrole -- Géologie -- Périodiques; Petroleum -- Geology; Submarine geology; Periodicals; Electronic journals; 551.468
• DOI: 10.1016/j.marpetgeo.2020.104255
• Languages: English
• ISSNs: 0264-8172

Abstract

Abstract: Gas hydrates are one of the most abundant clean energy resources and can effectively solve the energy crisis with a lower carbon footprint. Gas hydrates typically exhibit complex microscopic filling modes, including adhesive mode, cemented mode and scattered mode. Furthermore, the scientific understanding of such filling modes and the associated petrophysical parameters is essential for successful exploitation and development of hydrate formations. However, a precise identification of such filling modes remains a big challenge. Thus, here we proposed a novel hybrid gas hydrate filling mode identification method via digital rock technique. The hybrid method uses a combination of multiple methodologies. Firstly, the dry core samples were scanned by the high-resolution micro-scale 3D X-ray computed tomography (μCT) and the digital rock models were built. Then the resistivity was simulated as a function of gas hydrate saturation with three idealized gas hydrate-filling modes. The differences between the resistivity of three idealized gas hydrate-filling modes were analyzed, and based on the correlations obtained, the idealized gas hydrate saturation calculation models were formulated. We then considered well log data from a real hydrate reservoir in order to evaluate the application of proposed hydrate saturation model and identify the filling mode. Essentially, the gas hydrate saturation results from digital rock models and field well logging data are compared, and the filling modes in the research reservoir were successfully identified. Highlights: The effect of gas hydrate microscopic distribution on resistivity was investigated. Idealized gas hydrate saturation calculation models were developed. A novel method was proposed to identify gas hydrate filling modes.