关键词: 西加拿大沉积盆地, Duvernay 页岩, 地质特征, 流体分布

Abstract: Duvernay shale is the most important shale series for oil and gas enrichment and production in the Western Canada Sedimentary
Basin. It is a set of asphaltene rich dark shale formed during the maximum transgression period. Different from the domestic shale oil and gas reservoirs, Duvernay shale gas reservoir is characterized by high condensate content, great variation in condensate to gas ratio on the plane, and complex fluid distribution. The tectonic and sedimentary evolution, stratigraphy, geochemistry, reservoir characteristics, and fluid distribution of the Upper Devonian Duvernay shale in Simonette block in the Western Canada Sedimentary Basin are analyzed, and the exploration and development strategy of liquid-rich shale is proposed. The study results show that: (1) The upper part of Duvernay shale in Simonette block has large reservoir thickness, no carbonate interlayers, high TOC content, and good reservoir physical properties, which is the main exploration and development target layer; (2) Duvernay shale in Simonette block is located in a liquid-rich zone, with vitrinite reflectance (R_o) between 1.1%-1.6%, which is divided into three zones based on the condensate to gas ratio, namely the volatile oil zone, ultra-high gas condensate content zone and high gas condensate content zone. As the condensate-to-gas ratio (CGR) increases, the methane content gradually decreases, the crude oil density gradually increases, and the oil recovery factor gradually decreases; (3) In terms of exploration and development strategies,priority should be given to evaluation and development of ultra-high gas condensate content and high gas condensate content zones which are easier to be produced and have a high degree of producing rate, and followed by the volatile oil zone. Vertically, the high TOC shale layers are focused as the main targets.

Key words: Western Canada Sedimentary Basin, Duvernay shale, geological characteristics, fluid distribution