Jakob Haldorsen - Independent Researcher (original) (raw)

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Papers by Jakob Haldorsen

Enabling persistent monitoring of littoral areas with smart unmanned assets

Ocean Sensing and Monitoring XV

Defining a Steeply-Dipping Salt Flank in Mississippi with a New High-Certainty 3D Method

Salt-related structures are common along the U.S. Gulf Coast. Many conventional reservoirs (inclu... more Salt-related structures are common along the U.S. Gulf Coast. Many conventional reservoirs (including giant fields) are related to these structures as they create pathways and traps for hydrocarbons. Salt domes and some isolated salt bodies commonly have steeply inclined and complex boundaries. Steep boundaries are difficult to image directly with the surface seismic method because reflections from these boundaries tend to be down going and not recorded with receivers at or near the surface. Such steep boundaries are commonly marked by the absence of amplitude on a seismic image or the termination of sub horizontal features. Sedimentary layers are generally dragged upward during salt movement and may reach dips up to 80–85 degrees at the contact with the salt body. Commercial hydrocarbon accumulations have been found in the cap rock of salt domes as in the famous case at Spindletop, but, as documented by many commercial finds, more hydrocarbon accumulation is to be expected along th...

Fiberoptic Wide-Band Acoustic Multi-Component Sensors

OCEANS 2021: San Diego – Porto, 2021

We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a t... more We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a three-component accelerometer. Recent field data show that these optical sensors measure signals at frequencies from sub-Hz to several kHz. A relatively sparse array of these point sensors can be used to complement either a hydrophone array or fiber-optic Distributed Acoustic Sensing (DAS) technology to compensate for the inability of the DAS sensors to measure the wave-field polarization. A hybrid fiber-optic receiver array would provide vector information about the wave field, and provide a wide-band, wide aperture sensor array without requiring any electronics at the sensors.

Anisotropy evaluation in the Cuitlahuac field, Mexico, from cross-dipole sonics and borehole seismics generated by two orthogonal shear vibrators

make the case for use of borehole sonic data to increase understanding of a producing reservoir. ... more make the case for use of borehole sonic data to increase understanding of a producing reservoir. F rom borehole-sonic data, strongly dominated by modes refracted along the borehole, we can generate images of the formation around the well. This is achieved by using adaptive algorithms which separate the components of the wavefield refracted along the wellbore from the components escaping the wellbore and subsequently reflected at bed interfaces, fractures, and possible faults. The reflection data are converted into images of the formation using syntheticaperture processing. We show how the information provided by the sonic images at decimeter resolution can contribute to significant changes in the understanding of a reservoir.

SEG Technical Program Expanded Abstracts 2006, 2006

Borehole Acoustic Reflection Survey (BARS) data were acquired in the Brent formation in the Norwe... more Borehole Acoustic Reflection Survey (BARS) data were acquired in the Brent formation in the Norwegian North Sea in an exploration well for Hydro. In total, an interval of approximately 300 m was logged. Initial near-wellbore formation images were obtained within 24 hours. The quality of the sonic waveform data was very good. However, significant uncertainties in the actual tool depth caused by rough weather conditions during the time of logging, affected to some extent the coherence and the range of the formation images. The high-resolution image shows an interface dipping at 5° and clearly visible for at least 45 ft away from the well bore. The dip of the interface is in agreement with the expected local geology at the well location. The highresolution event can be correlated to a 1 m thin coal bed intersecting the borehole and indicated by the petrophysical logs. The coal bed is interpreted as the Top Etive Formation. The BARS images helped characterizing the local geology and the reservoir. In addition, the highresolution sonic images augment the understanding of the seismic responses in the reservoir section.

Oceans 21, 2021

We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a t... more We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a three-component accelerometer. Recent field data show that these optical sensors measure signals at frequencies from sub-Hz to several kHz. A relatively sparse array of these point sensors can be used to complement either a hydrophone array or fiber-optic Distributed Acoustic Sensing (DAS) technology to compensate for the inability of the DAS sensors to measure the wave-field polarization. A hybrid fiber-optic receiver array would provide vector information about the wave field, and provide a wide-band, wide aperture sensor array without requiring any electronics at the sensors.

Method for merging position information with measurements and filtering to obtain high-quality images that are positioned accurately with respect to global coordinates

VSP Imaging of Acoustic Interfaces

Leveraging multiple source locations and the total wavefield to create a more robust salt proximity survey: Gulf of Mexico example, Tahiti Field

SEG Technical Program Expanded Abstracts 2019

Multi-component seismic MWD data processing method

Method of vertical seismic profiling

Use of vibrators in a marine seismic source

Seg Technical Program Expanded Abstracts, 1999

Optimizing well construction: Full-waveform data from while-drilling seismic measurements

Journal of Petroleum Technology, 2003

Methods and Apparatus for Determining Slowness of Wavefronts

Multiple-axis linearly-propelled rotating sensor apparatus

Seg Technical Program Expanded Abstracts, 2008

A controlled simultaneous VSP and surface seismic field test was conducted to evaluate the evolut... more A controlled simultaneous VSP and surface seismic field test was conducted to evaluate the evolution of the vibroseis chirp wavelet. We verify that the partitioning of seismic energy is independent of sweep rate for different sweep designs. We demonstrate under what conditions the seismic bandwidth can be extended using the semblanceweighted deterministic deconvolution process in the uncorrelated domain for zero-offset VSP, walk-away VSP, and simultaneous borehole and surface seismic data. The deterministic deconvolution process requires knowledge of the chirp wavelet in order to transfer the harmonic energy from the seismic noise domain into the seismic signal domain. Its performance depends on knowledge of the chirp signature and ambient noise. As expected, the ambient noise conditions in the well were extremely low as compared to the higher noise levels recorded in the surface seismic data. Under low ambient noise conditions, the semblance-weighted deconvolution can extend the recoverable bandwidth beyond the predefined pilot bandwidth for both the VSP and surface seismic data independently. The high level of surface ambient noise conditions in our field test limited the effectiveness of the VSP operators to extend the recoverable bandwidth of the surface seismic data.

Method for deconvolution of unknown source signatures from unknown waveform data

Methods and Apparatus to Image Subsurface Formation Features

Enabling persistent monitoring of littoral areas with smart unmanned assets

Ocean Sensing and Monitoring XV

Defining a Steeply-Dipping Salt Flank in Mississippi with a New High-Certainty 3D Method

Salt-related structures are common along the U.S. Gulf Coast. Many conventional reservoirs (inclu... more Salt-related structures are common along the U.S. Gulf Coast. Many conventional reservoirs (including giant fields) are related to these structures as they create pathways and traps for hydrocarbons. Salt domes and some isolated salt bodies commonly have steeply inclined and complex boundaries. Steep boundaries are difficult to image directly with the surface seismic method because reflections from these boundaries tend to be down going and not recorded with receivers at or near the surface. Such steep boundaries are commonly marked by the absence of amplitude on a seismic image or the termination of sub horizontal features. Sedimentary layers are generally dragged upward during salt movement and may reach dips up to 80–85 degrees at the contact with the salt body. Commercial hydrocarbon accumulations have been found in the cap rock of salt domes as in the famous case at Spindletop, but, as documented by many commercial finds, more hydrocarbon accumulation is to be expected along th...

Fiberoptic Wide-Band Acoustic Multi-Component Sensors

OCEANS 2021: San Diego – Porto, 2021

We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a t... more We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a three-component accelerometer. Recent field data show that these optical sensors measure signals at frequencies from sub-Hz to several kHz. A relatively sparse array of these point sensors can be used to complement either a hydrophone array or fiber-optic Distributed Acoustic Sensing (DAS) technology to compensate for the inability of the DAS sensors to measure the wave-field polarization. A hybrid fiber-optic receiver array would provide vector information about the wave field, and provide a wide-band, wide aperture sensor array without requiring any electronics at the sensors.

Anisotropy evaluation in the Cuitlahuac field, Mexico, from cross-dipole sonics and borehole seismics generated by two orthogonal shear vibrators

make the case for use of borehole sonic data to increase understanding of a producing reservoir. ... more make the case for use of borehole sonic data to increase understanding of a producing reservoir. F rom borehole-sonic data, strongly dominated by modes refracted along the borehole, we can generate images of the formation around the well. This is achieved by using adaptive algorithms which separate the components of the wavefield refracted along the wellbore from the components escaping the wellbore and subsequently reflected at bed interfaces, fractures, and possible faults. The reflection data are converted into images of the formation using syntheticaperture processing. We show how the information provided by the sonic images at decimeter resolution can contribute to significant changes in the understanding of a reservoir.

SEG Technical Program Expanded Abstracts 2006, 2006

Borehole Acoustic Reflection Survey (BARS) data were acquired in the Brent formation in the Norwe... more Borehole Acoustic Reflection Survey (BARS) data were acquired in the Brent formation in the Norwegian North Sea in an exploration well for Hydro. In total, an interval of approximately 300 m was logged. Initial near-wellbore formation images were obtained within 24 hours. The quality of the sonic waveform data was very good. However, significant uncertainties in the actual tool depth caused by rough weather conditions during the time of logging, affected to some extent the coherence and the range of the formation images. The high-resolution image shows an interface dipping at 5° and clearly visible for at least 45 ft away from the well bore. The dip of the interface is in agreement with the expected local geology at the well location. The highresolution event can be correlated to a 1 m thin coal bed intersecting the borehole and indicated by the petrophysical logs. The coal bed is interpreted as the Top Etive Formation. The BARS images helped characterizing the local geology and the reservoir. In addition, the highresolution sonic images augment the understanding of the seismic responses in the reservoir section.

Oceans 21, 2021

We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a t... more We describe a range of novel optical point sensors, including a microphone, a hydrophone, and a three-component accelerometer. Recent field data show that these optical sensors measure signals at frequencies from sub-Hz to several kHz. A relatively sparse array of these point sensors can be used to complement either a hydrophone array or fiber-optic Distributed Acoustic Sensing (DAS) technology to compensate for the inability of the DAS sensors to measure the wave-field polarization. A hybrid fiber-optic receiver array would provide vector information about the wave field, and provide a wide-band, wide aperture sensor array without requiring any electronics at the sensors.

Method for merging position information with measurements and filtering to obtain high-quality images that are positioned accurately with respect to global coordinates

VSP Imaging of Acoustic Interfaces

Leveraging multiple source locations and the total wavefield to create a more robust salt proximity survey: Gulf of Mexico example, Tahiti Field

SEG Technical Program Expanded Abstracts 2019

Multi-component seismic MWD data processing method

Method of vertical seismic profiling

Use of vibrators in a marine seismic source

Seg Technical Program Expanded Abstracts, 1999

Optimizing well construction: Full-waveform data from while-drilling seismic measurements

Journal of Petroleum Technology, 2003

Methods and Apparatus for Determining Slowness of Wavefronts

Multiple-axis linearly-propelled rotating sensor apparatus

Seg Technical Program Expanded Abstracts, 2008

A controlled simultaneous VSP and surface seismic field test was conducted to evaluate the evolut... more A controlled simultaneous VSP and surface seismic field test was conducted to evaluate the evolution of the vibroseis chirp wavelet. We verify that the partitioning of seismic energy is independent of sweep rate for different sweep designs. We demonstrate under what conditions the seismic bandwidth can be extended using the semblanceweighted deterministic deconvolution process in the uncorrelated domain for zero-offset VSP, walk-away VSP, and simultaneous borehole and surface seismic data. The deterministic deconvolution process requires knowledge of the chirp wavelet in order to transfer the harmonic energy from the seismic noise domain into the seismic signal domain. Its performance depends on knowledge of the chirp signature and ambient noise. As expected, the ambient noise conditions in the well were extremely low as compared to the higher noise levels recorded in the surface seismic data. Under low ambient noise conditions, the semblance-weighted deconvolution can extend the recoverable bandwidth beyond the predefined pilot bandwidth for both the VSP and surface seismic data independently. The high level of surface ambient noise conditions in our field test limited the effectiveness of the VSP operators to extend the recoverable bandwidth of the surface seismic data.

Method for deconvolution of unknown source signatures from unknown waveform data

Methods and Apparatus to Image Subsurface Formation Features