Within a period of six months, from the end of 2014 and into June 2015, four consecutive discover... more Within a period of six months, from the end of 2014 and into June 2015, four consecutive discoveries were made in the deep water Vøring Basin in the Norwegian Sea. These wells add to a total of eight wells drilled on structural highs along an axis extending from the Vema dome to the south up to the Nyk High to the north. Seven out of the eight wells have been gas discoveries, while one of them has in addition proven a 4-meter-thick oil leg under the gas (Senfrid North, 6706/12-2). Several 2D CSEM survey lines were acquired in the area in 2003, 2007 and 2010, testing nine different structural highs, of which four have been tested with drilling. A review of the CSEM data shows a 100% correlation between our interpretations and the drilling results, with two out of the four interpretations made prior to drilling the Ivory (6707/10-3s, 2014) and the Gymir (6706/11-2, 2015) gas discoveries. The other two true interpretations are the Vema (6706/11-1, 2001) dry well and the Luva (6707/10-1...
L'invention concerne un systeme et un procede pour l'elimination de depots dans une zone ... more L'invention concerne un systeme et un procede pour l'elimination de depots dans une zone d'element optique au contact avec un liquide, definie comme une interface optique. Le systeme comprend une source de laser pulse que l'on oriente a travers l'element optique au niveau de l'interface optique. Ladite source emet de la lumiere a une longueur d'onde qui est absorbee par les depots susmentionnes.
Une lampe pour la therapie photodynamique comprend une enveloppe (10, 11, 12, 13) qui renferme un... more Une lampe pour la therapie photodynamique comprend une enveloppe (10, 11, 12, 13) qui renferme une source de lumiere formee de deux reseaux (20) de DEL (21). Les DEL sont disposees sous forme d'un motif en nid d'abeille et presentent une longueur d'onde maximale de l'ordre de 630-640 nm. Sous les DEL se situe un ensemble lentille (22) contenant une lentille (23) destinee a chaque DEL. Au-dessous se situe un diffuseur (7). Les lentilles sont disposees suivant un motif en nid d'abeille et servent a concentrer la lumiere en un faisceau sensiblement parallele et etroit.
... about the potential of remote controlled-source electromagnetic technology (Young and Cox 198... more ... about the potential of remote controlled-source electromagnetic technology (Young and Cox 1981, Chave and Cox 1982, Webb et al ... by Mikhail Boulaenko1,2, Jonny Hesthammer1,2, Alexander Vereshagin1, Peter Gelting1, Roy Davies1 and Torolf Wedberg1 1Rocksource ASA ...
72nd EAGE Conference and Exhibition incorporating SPE EUROPEC 2010, 2010
This presentation focuses on how new prospectivity has been identified and developed in a quite m... more This presentation focuses on how new prospectivity has been identified and developed in a quite mature area on the Norwegian Shelf. The area of interest was recently awarded to PL 559 in the APA 2009 licensing round. It is located at the Nordland Ridge in blocks 6608/10 and 6608/11 just east of several discoveries and fields. The area has previously been part of license PL 128 since 1986, but was stepwise relinquished over the last few years due to disappointing well results where many of the traditional prospects have been proved dry. In the current study the entire area has been interpreted on 3D seismic, which has been tied to nearby wells. Using a new play concept and integrating data we have identified multiple attractive prospects of high commercial value at several different target intervals which have all been proven to contain oil in discovery wells immediately to the west. Studies including pressure evaluation, fault seal studies and migration modeling have been performed to mature and de-risk the prospects. CSEM modeling confirmed that the prospectivity was feasible for de-risking using CSEM technology, and both proprietary CSEM data as well as published material has been used in order to de-risk the prospectivity further.
The concept of CSEM surveys is based on the knowledge that the propagation of an electromagnetic ... more The concept of CSEM surveys is based on the knowledge that the propagation of an electromagnetic (EM) Held induced in a conductive subsurface is mainly affected by spatial distribution of resistivity. In marine environments, saltwater-tilled sediments typically ...
The design, modeling, building and testing of a longitudinally laser pumped continuous wave Nd:YA... more The design, modeling, building and testing of a longitudinally laser pumped continuous wave Nd:YAG laser is reported. The diode laser is a temperature stabilized 200 mW, 100 micrometer wide bar operating at 810 nm wavelength. Nd:YAG laser operation is demonstrated both at 1.06 and 1.32 micrometers with transverse electromagnetic mode output powers of 59 and 19mW respectively, and optical conversion
Microscopy, Holography, and Interferometry in Biomedicine, 1994
Optical diffraction tomography (ODT) is a novel imaging technique in which a transparent object i... more Optical diffraction tomography (ODT) is a novel imaging technique in which a transparent object is illuminated from many different directions. The object's complex refractive index distribution is reconstructed digitally from the scattered field data by means of a reconstruction algorithm. Preliminary experimental results are presented for the imaging of an object whose refractive index and shape are known a priori. The results show that both the refractive index and the shape may be reconstructed accurately by the proposed ODT technique.
Optical diffraction tomography (ODT) is applied to reconstruct the cross-sectional, complex refra... more Optical diffraction tomography (ODT) is applied to reconstruct the cross-sectional, complex refractive index distribution of cylindrical objects. Experimental reconstructions showing noticeable image contrast for refractive index variations of about 0.001, and having a spatial resolution of about 2 μm, are obtained for objects with cross-sectional diameters of about 100 μm. The results demonstrate that ODT can be used for quantitative
Particle & Particle Systems Characterization, 1995
A tutorial review of diffraction tomography is given along with an overview of recent advances of... more A tutorial review of diffraction tomography is given along with an overview of recent advances of this technique in borehole geophysics, ultrasonic imaging, and optical microscopy. First, the basic principles of diffraction tomography are presented. Then, we discuss a generalized inversion algorithm, valid for irregularly spaced data and a non-uniform background, and present reconstructions based on ultrasonic water tank data and underground georadar data. Next, we discuss a hybrid filtered backpropagation algorithm for ultrasonic and optical imaging. Quantitative images, based on experimental data, are presented of objects embedded in water or in biological tissue and probed by ultrasound, and of fibers embedded in an index matching liquid and probed by laser light.
Optical diffraction tomography (ODT) is examined experimentally by reconstruction of a cross sect... more Optical diffraction tomography (ODT) is examined experimentally by reconstruction of a cross section of a transparent, cylindrical object with known geometry and refractive index. The object is immersed in three liquids of different refractive index to produce varying degrees of weak scattering. In each case the reconstructed size, shape, and refractive index are in good agreement with the known characteristics.
In this paper, we review recent results obtained using optical diffraction tomography (ODT) to ge... more In this paper, we review recent results obtained using optical diffraction tomography (ODT) to generate the cross sectional, complex refractive index distribution of weakly scattering cylindrical objects (fibres). Two different ODT algorithms, based on inverse diffraction in combination with either filtered backpropagation or filtered backprojection, have been applied for reconstruction. Using both procedures, images showing noticeable image contrast for refractive index variations of about 0.001, and having a spatial resolution of about , have been obtained for objects with cross sectional diameters ranging from about to about . The good agreement between the two reconstruction algorithms suggests that both procedures can be used for quantitative imaging of semi-transparent fibres, and that three-dimensional imaging can be obtained in a relatively simple manner.
Pure and Applied Optics: Journal of the European Optical Society Part A, 1995
We compare three different phase retrieval methods for applications in optical diffraction tomogr... more We compare three different phase retrieval methods for applications in optical diffraction tomography (ODT). The first method is based on Gabor holography and is limited by the 'twin-image' problem. The second is an iterative approach for which the uniqueness of the retrieved phase is questionable. In the third method the phase is measured by phase shifting interferometry (PSI), but this
We compare the filtered backpropagation algorithm with the filtered backprojection algorithm for ... more We compare the filtered backpropagation algorithm with the filtered backprojection algorithm for reconstructing the complex refractive-index distribution of semitransparent, cylindrical objects. Before reconstruction, the recorded scattered light is propagated back to the reconstruction area by inverse diffraction. Our comparison is based on computer-simulated data, and experimental optical data obtained from fibers with step-index, graded-index, and uniform-index distributions. The results show that both the filtered backpropagation algorithm and the filtered backprojection algorithm can produce accurate reconstructions of the complex refractive-index distribution as long as the weak-scattering approximation is valid. The good agreement between the results obtained from these two reconstruction algorithms indicates that the errors introduced by the assumption of straight-line propagation inside the object are negligible compared with those introduced by the weak-scattering approximation.
Within a period of six months, from the end of 2014 and into June 2015, four consecutive discover... more Within a period of six months, from the end of 2014 and into June 2015, four consecutive discoveries were made in the deep water Vøring Basin in the Norwegian Sea. These wells add to a total of eight wells drilled on structural highs along an axis extending from the Vema dome to the south up to the Nyk High to the north. Seven out of the eight wells have been gas discoveries, while one of them has in addition proven a 4-meter-thick oil leg under the gas (Senfrid North, 6706/12-2). Several 2D CSEM survey lines were acquired in the area in 2003, 2007 and 2010, testing nine different structural highs, of which four have been tested with drilling. A review of the CSEM data shows a 100% correlation between our interpretations and the drilling results, with two out of the four interpretations made prior to drilling the Ivory (6707/10-3s, 2014) and the Gymir (6706/11-2, 2015) gas discoveries. The other two true interpretations are the Vema (6706/11-1, 2001) dry well and the Luva (6707/10-1...
L'invention concerne un systeme et un procede pour l'elimination de depots dans une zone ... more L'invention concerne un systeme et un procede pour l'elimination de depots dans une zone d'element optique au contact avec un liquide, definie comme une interface optique. Le systeme comprend une source de laser pulse que l'on oriente a travers l'element optique au niveau de l'interface optique. Ladite source emet de la lumiere a une longueur d'onde qui est absorbee par les depots susmentionnes.
Une lampe pour la therapie photodynamique comprend une enveloppe (10, 11, 12, 13) qui renferme un... more Une lampe pour la therapie photodynamique comprend une enveloppe (10, 11, 12, 13) qui renferme une source de lumiere formee de deux reseaux (20) de DEL (21). Les DEL sont disposees sous forme d'un motif en nid d'abeille et presentent une longueur d'onde maximale de l'ordre de 630-640 nm. Sous les DEL se situe un ensemble lentille (22) contenant une lentille (23) destinee a chaque DEL. Au-dessous se situe un diffuseur (7). Les lentilles sont disposees suivant un motif en nid d'abeille et servent a concentrer la lumiere en un faisceau sensiblement parallele et etroit.
... about the potential of remote controlled-source electromagnetic technology (Young and Cox 198... more ... about the potential of remote controlled-source electromagnetic technology (Young and Cox 1981, Chave and Cox 1982, Webb et al ... by Mikhail Boulaenko1,2, Jonny Hesthammer1,2, Alexander Vereshagin1, Peter Gelting1, Roy Davies1 and Torolf Wedberg1 1Rocksource ASA ...
72nd EAGE Conference and Exhibition incorporating SPE EUROPEC 2010, 2010
This presentation focuses on how new prospectivity has been identified and developed in a quite m... more This presentation focuses on how new prospectivity has been identified and developed in a quite mature area on the Norwegian Shelf. The area of interest was recently awarded to PL 559 in the APA 2009 licensing round. It is located at the Nordland Ridge in blocks 6608/10 and 6608/11 just east of several discoveries and fields. The area has previously been part of license PL 128 since 1986, but was stepwise relinquished over the last few years due to disappointing well results where many of the traditional prospects have been proved dry. In the current study the entire area has been interpreted on 3D seismic, which has been tied to nearby wells. Using a new play concept and integrating data we have identified multiple attractive prospects of high commercial value at several different target intervals which have all been proven to contain oil in discovery wells immediately to the west. Studies including pressure evaluation, fault seal studies and migration modeling have been performed to mature and de-risk the prospects. CSEM modeling confirmed that the prospectivity was feasible for de-risking using CSEM technology, and both proprietary CSEM data as well as published material has been used in order to de-risk the prospectivity further.
The concept of CSEM surveys is based on the knowledge that the propagation of an electromagnetic ... more The concept of CSEM surveys is based on the knowledge that the propagation of an electromagnetic (EM) Held induced in a conductive subsurface is mainly affected by spatial distribution of resistivity. In marine environments, saltwater-tilled sediments typically ...
The design, modeling, building and testing of a longitudinally laser pumped continuous wave Nd:YA... more The design, modeling, building and testing of a longitudinally laser pumped continuous wave Nd:YAG laser is reported. The diode laser is a temperature stabilized 200 mW, 100 micrometer wide bar operating at 810 nm wavelength. Nd:YAG laser operation is demonstrated both at 1.06 and 1.32 micrometers with transverse electromagnetic mode output powers of 59 and 19mW respectively, and optical conversion
Microscopy, Holography, and Interferometry in Biomedicine, 1994
Optical diffraction tomography (ODT) is a novel imaging technique in which a transparent object i... more Optical diffraction tomography (ODT) is a novel imaging technique in which a transparent object is illuminated from many different directions. The object's complex refractive index distribution is reconstructed digitally from the scattered field data by means of a reconstruction algorithm. Preliminary experimental results are presented for the imaging of an object whose refractive index and shape are known a priori. The results show that both the refractive index and the shape may be reconstructed accurately by the proposed ODT technique.
Optical diffraction tomography (ODT) is applied to reconstruct the cross-sectional, complex refra... more Optical diffraction tomography (ODT) is applied to reconstruct the cross-sectional, complex refractive index distribution of cylindrical objects. Experimental reconstructions showing noticeable image contrast for refractive index variations of about 0.001, and having a spatial resolution of about 2 μm, are obtained for objects with cross-sectional diameters of about 100 μm. The results demonstrate that ODT can be used for quantitative
Particle & Particle Systems Characterization, 1995
A tutorial review of diffraction tomography is given along with an overview of recent advances of... more A tutorial review of diffraction tomography is given along with an overview of recent advances of this technique in borehole geophysics, ultrasonic imaging, and optical microscopy. First, the basic principles of diffraction tomography are presented. Then, we discuss a generalized inversion algorithm, valid for irregularly spaced data and a non-uniform background, and present reconstructions based on ultrasonic water tank data and underground georadar data. Next, we discuss a hybrid filtered backpropagation algorithm for ultrasonic and optical imaging. Quantitative images, based on experimental data, are presented of objects embedded in water or in biological tissue and probed by ultrasound, and of fibers embedded in an index matching liquid and probed by laser light.
Optical diffraction tomography (ODT) is examined experimentally by reconstruction of a cross sect... more Optical diffraction tomography (ODT) is examined experimentally by reconstruction of a cross section of a transparent, cylindrical object with known geometry and refractive index. The object is immersed in three liquids of different refractive index to produce varying degrees of weak scattering. In each case the reconstructed size, shape, and refractive index are in good agreement with the known characteristics.
In this paper, we review recent results obtained using optical diffraction tomography (ODT) to ge... more In this paper, we review recent results obtained using optical diffraction tomography (ODT) to generate the cross sectional, complex refractive index distribution of weakly scattering cylindrical objects (fibres). Two different ODT algorithms, based on inverse diffraction in combination with either filtered backpropagation or filtered backprojection, have been applied for reconstruction. Using both procedures, images showing noticeable image contrast for refractive index variations of about 0.001, and having a spatial resolution of about , have been obtained for objects with cross sectional diameters ranging from about to about . The good agreement between the two reconstruction algorithms suggests that both procedures can be used for quantitative imaging of semi-transparent fibres, and that three-dimensional imaging can be obtained in a relatively simple manner.
Pure and Applied Optics: Journal of the European Optical Society Part A, 1995
We compare three different phase retrieval methods for applications in optical diffraction tomogr... more We compare three different phase retrieval methods for applications in optical diffraction tomography (ODT). The first method is based on Gabor holography and is limited by the 'twin-image' problem. The second is an iterative approach for which the uniqueness of the retrieved phase is questionable. In the third method the phase is measured by phase shifting interferometry (PSI), but this
We compare the filtered backpropagation algorithm with the filtered backprojection algorithm for ... more We compare the filtered backpropagation algorithm with the filtered backprojection algorithm for reconstructing the complex refractive-index distribution of semitransparent, cylindrical objects. Before reconstruction, the recorded scattered light is propagated back to the reconstruction area by inverse diffraction. Our comparison is based on computer-simulated data, and experimental optical data obtained from fibers with step-index, graded-index, and uniform-index distributions. The results show that both the filtered backpropagation algorithm and the filtered backprojection algorithm can produce accurate reconstructions of the complex refractive-index distribution as long as the weak-scattering approximation is valid. The good agreement between the results obtained from these two reconstruction algorithms indicates that the errors introduced by the assumption of straight-line propagation inside the object are negligible compared with those introduced by the weak-scattering approximation.
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Papers by Torolf Wedberg