Gudbjerg, Jacob

Jensen, Karsten Høgh

Lassen, Rune Nørbæk

Sonnenborg, Torben Obel

Zibar, Majken Caroline Looms

English

Copenhagen University Research Information System

u n i ve r s i t y  o f  co pe n h ag e n  Københavns UniversitetMonitoring CO2 gas-phase injection in a shallow sand aquifer using cross boreholeGPR and modeled with T2VOC multi-phase codeLassen, Rune Nørbæk; Jensen, Karsten Høgh; Zibar, Majken Caroline Looms; Sonnenborg,Torben Obel; Gudbjerg, JacobPublication date:2013Document versionPeer reviewed versionCitation for published version (APA):Lassen, R. N., Jensen, K. H., Zibar, M. C. L., Sonnenborg, T. O., & Gudbjerg, J. (2013). Monitoring CO2 gas-phase injection in a shallow sand aquifer using cross borehole GPR and modeled with T2VOC multi-phase code.Abstract from American Geophysical Union Fall Meeting, San Francisco, United States.Download date: 03. Feb. 2020Final ID: H51H-1297Monitoring CO2 gas-phase injection in a shallow sand aquifer using cross borehole GPR and modeled with T2VOCmulti-phase codeR. N. Lassen; 1; K.  Jensen; 1; M. C. Looms; 1; T.  Sonnenborg; 2; J.  Gudbjerg; 3; 1. University of Copenhagen, Copenhagen, Denmark. 2. Geological survey of Denmark and Greenland, Copenhagen, Denmark. 3. Jacob Gudbjerg Consulting, Copenhagen, Denmark.  Body: Risk assessment of potential leakage is an important issue that needs attention in designing effective storageschemes for CO2 storage. Leaking gas may threat groundwater resources and be a liability if pooled up in buildings.We have designed an experiment where we were track the movement of an injected CO2 gas-phase using crossborehole GPR in an unconfined sandy aquifer located in the southwestern part of Denmark. The geology at the field site has been determined using GPR- data, natural gamma ray logging in boreholes, coressampled with a Geoprobe soil-sampling tool and grain size analysis of the cores. From these measurements the fieldsite geology can be divided into three geological zones. The first zone is an approximately 4 m fine aeolian sand; thesecond zone is poorly sorted glacial deposits dominated by sand down to 9 m; and the the last zone from 9 m anddown consist of well-sorted medium melt water sand. In total we conducted four short injection experiments all of them producing very similar results. The screen of theinjection well was 10 m below ground level or 8 m below the water table. An array of six GPR boreholes was installedaround the injection well and downwards of dominating gas flow direction. GPR-data were acquired in zero-offset (1D)and multiple-offset (2D) configurations prior and during the injection. All sets of GPR data showed that a plumedeveloped at the depth of the injection screen and that the injected gas primarily spread towards South-East andnever breach a barrier around 5 m depth. This corresponded very well with the natural gamma logs, which resulted inhigher readings from 4-6.5 m depth. The grain size analyses confirmed that there is a fine sediment layer throughoutthe area at 4-6 meters depth. We guesstimated van Genucthen parameters from the grain size analysis and used as input to the numerical modeland GPR data were used for calibration. The numerical model enabled us to test minimum entry pressure required forthe fine sediment layer to function as a barrier and the “leakage” rate required for the gas phase to breach the barrier.

Monitoring CO2 gas-phase injection in a shallow sand aquifer using cross borehole GPR and modeled with T2VOC multi-phase code

https://curis.ku.dk/ws/files/109414285/Lassen_et_al.pdf

Monitoring CO2 gas-phase injection in a shallow sand aquifer using cross borehole GPR and modeled with T2VOC multi-phase code

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