{"title":"Assessing the impact of hydrodynamics on capillary seal capacity: application of the Manzocchi & Childs model in trap analysis workflows","authors":"Neil T. Grant","doi":"10.1144/petgeo2023-016","DOIUrl":null,"url":null,"abstract":"The evaluation of seal in conventional stratigraphic and structural traps requires the characterisation of the capillary top seal to assess the capacity to hold a hydrocarbon column. Typically, this seal analysis addresses the static seal and does not consider the role that hydrodynamics (the flow of water into or out of the shale seal) may play in influencing the seal capacity. Although possessing extremely low permeability, shale seals are not perfect seals and water can move through them under an imposed hydraulic gradient. Likewise, water can flow through trapped hydrocarbon columns even though relative permeabilities can be very low (Teige et al., 2005). The impact of this flow on the capillary seal capacity can, in theory, be quite profound and should be considered in seal analysis workflows. This paper revisits the Manzocchi & Childs (2013) model for hydrodynamic effects on capillary seals and employs it directly in real-world trap analysis. The implementation of this model is described, and a workflow developed to incorporate the impact of hydrodynamics into column height prediction. The technique is applied to several known over-pressured fields from the Norwegian continental shelf to evaluate its applicability. Preliminary results from Monte Carlo modelling are promising and appear to offer some agreement between the observed column heights and the predicted hydrodynamic seal-controlled columns, dependant on the parameterisation used. Further testing is ongoing, but the methodology should be considered for routine application, particularly in exploration prospect evaluation. The impact of hydrodynamics on seal capacities should not be discounted. Thematic collection: This article is part of the Fault and top seals 2022 collection available at: https://www.lyellcollection.org/topic/collections/fault-and-top-seals-2022","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Petroleum Geoscience","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1144/petgeo2023-016","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The evaluation of seal in conventional stratigraphic and structural traps requires the characterisation of the capillary top seal to assess the capacity to hold a hydrocarbon column. Typically, this seal analysis addresses the static seal and does not consider the role that hydrodynamics (the flow of water into or out of the shale seal) may play in influencing the seal capacity. Although possessing extremely low permeability, shale seals are not perfect seals and water can move through them under an imposed hydraulic gradient. Likewise, water can flow through trapped hydrocarbon columns even though relative permeabilities can be very low (Teige et al., 2005). The impact of this flow on the capillary seal capacity can, in theory, be quite profound and should be considered in seal analysis workflows. This paper revisits the Manzocchi & Childs (2013) model for hydrodynamic effects on capillary seals and employs it directly in real-world trap analysis. The implementation of this model is described, and a workflow developed to incorporate the impact of hydrodynamics into column height prediction. The technique is applied to several known over-pressured fields from the Norwegian continental shelf to evaluate its applicability. Preliminary results from Monte Carlo modelling are promising and appear to offer some agreement between the observed column heights and the predicted hydrodynamic seal-controlled columns, dependant on the parameterisation used. Further testing is ongoing, but the methodology should be considered for routine application, particularly in exploration prospect evaluation. The impact of hydrodynamics on seal capacities should not be discounted. Thematic collection: This article is part of the Fault and top seals 2022 collection available at: https://www.lyellcollection.org/topic/collections/fault-and-top-seals-2022
期刊介绍:
Petroleum Geoscience is the international journal of geoenergy and applied earth science, and is co-owned by the Geological Society of London and the European Association of Geoscientists and Engineers (EAGE).
Petroleum Geoscience transcends disciplinary boundaries and publishes a balanced mix of articles covering exploration, exploitation, appraisal, development and enhancement of sub-surface hydrocarbon resources and carbon repositories. The integration of disciplines in an applied context, whether for fluid production, carbon storage or related geoenergy applications, is a particular strength of the journal. Articles on enhancing exploration efficiency, lowering technological and environmental risk, and improving hydrocarbon recovery communicate the latest developments in sub-surface geoscience to a wide readership.
Petroleum Geoscience provides a multidisciplinary forum for those engaged in the science and technology of the rock-related sub-surface disciplines. The journal reaches some 8000 individual subscribers, and a further 1100 institutional subscriptions provide global access to readers including geologists, geophysicists, petroleum and reservoir engineers, petrophysicists and geochemists in both academia and industry. The journal aims to share knowledge of reservoir geoscience and to reflect the international nature of its development.