A Pilot 3000m Drilling for Characterizing a Candidate Deep Saline Aquifer in Western Taiwan

Abstract

Abstract Prior to the very first pilot injection in a test site in west Taiwan, a characterization well (M-1) with a vertical depth up to 3000m underground is regarded necessary to investigate the geological condition and allocate the exact depth and thickness of target formations. The drilling of the upper half section of the 3000m drilling, from surface to depth of 1500m, has been completed by August/2012. Cutting material had been collected for obtaining less informative geological data. By November 14, 2013, after reaching the 3000m drilling target, an overall 1379m long (92% core recovery out of 1505-3005mRT) rock cores at the lower half section of the 3000m drilling containing the major target cap rock (C Formation) and reservoir rock (K Formation) were continuously recovered. Most of the recovered cores had been extensively tested and analyzed to evaluate the basic properties regarding rock injectivity and integrity for evaluating the carbon storage potential. The general project findings of M-1 pilot characterization well demonstrate that the feasibility of the preferred test site. However, it has been noted that frequent changes of thin layers of sandstone and shale reflect a storage mechanism exhibiting an intra-formational seal nature of the studied sedimentary foreland basin. According the drilling investigation, it is recognized that the site is not only suitable for a small amount pilot injection test but also a commercial developing potential site for large amount carbon storage in a deep saline aquifer. However, the typical intra-formational thin reservoirs may constitute a major challenge for the future sequestration design and operation.