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DTU Olie og Gas
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by dhrtc is to describe the
chalk
strata down to the one-metre scale. to begin with, the work will be car- ried out on land, at stevns klint on zealand and in a
chalk
quarry at rør- dal near aalborg. ?it?s much easier and less expensive to carry out
seismic
measurements on land compared to at sea, and we are very lucky that the
chalk
strata at stevns klint and in rørdal resem- ble the formations in the north sea where the
oil
is found. ?is means that knowledge obtained onshore is also applicable for offshore locations,? says janina kammann, a geophysicist and phd student at the department of geosciences and natural resource management at the university of co- penhagen. she is working on combining two
seismic
measuring methods, which to- gether will produce new, high-resolu- tion images. it is the first time that the method is being used to describe the porosity of denmark?s
chalk
formations. interdisciplinary collaboration when geophysicist janina kammann works in the field with the universi- ty?s new measuring equipment, she is accompanied by geologists from the natural history museum of denmark. ?e geologists take samples of the sub- s
oil
, which are used to qualify the seis- mic measurements. subsequently, the researchers in- volved in the interdisciplinary project compare the new knowledge about the
chalk
strata on land with existing knowledge about the geology of the north sea. eventually, this will lead to geophys- icists at the niels bohr institute pre- paring so-called geostatic models. ?is is a sort of map of the geology of the north sea, which the
oil
industry can use in its efforts to recover
oil
and gas. surface vibrator source elvis iii basically, janina kammann obtains her results by both stamping on and z y x p-wave sv-wave sh-wave wave propagation direction polarisation z y x z y x
seismic
measurements with p and s-waves. illustration: janina kammann janina kammann?s ph.d-project near-surface
seismic
investigation of reservoir rocks. the reflec- tion
seismic
method is widely used in both offshore and onshore mapping and description of hydrocarbon reservoirs. this projects studies onshore rocks that are analogous to rocks in the north sea that form reservoir to
oil
and gas using p- and s-wave
seismic
data recording. as part of the project the phd student will set up and carry out testing of the
seismic
instrumentation. the p- and s-wave data sets are integrated with borehole data and geological mapping and used to construct new models of key rock physical parameters, which are used in new reservoir models. 13 dhrtc 2016 demo model awf1 development of ekofisk the demo model is inspired by the kraka field, where the
oil
is found in a
chalk
layer in the subsurface, which is called ekofisk. the
oil
produced in this field is today brought to the surface by a natural- ly occuring over pressure in the resevoir. however, the pressure is declining quickly, and therefore only a very small amount of the
oil
will be recovered. in the kraka field, it is expected that only about 12 per cent of the
oil
can be recovered based on the natural over pressure. by pumping water down into the
oil
y geological strata, today it is perhaps possible to squeeze more of
oil
from the reservoir. dhrtc?s hypothesis ? changing the chemical properties of the injected water can increase
oil
production ? optimizing the positioning of the wells in relation to the water and
oil
as well as the properties of the
chalk
strata can increase
oil
production dhrtc research in order to achieve the objective of improv- ing the existing water injection technolo- gy, dhrtc is conducting research into, for example: ? the identification of suitable ior/eor methods ? the working process in connection with the development of a dfn geomodel ? outcrop descriptions for the calibration of models for subsurface fractures ? processes for water-based recovery and laboratory-scale experiments ? core flooding models for use in laborato- ry-scale experiments
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