Login| Library| Events|Contact| Home
Home > Media & Events > Technical Abstracts

Technical Abstracts

A Wealth of Geoscientific Research

Search our large e-library of technical abstracts by entering at least one search criterion:

Category Where Published: When Published:
Keyword(s): Author(s):

Results: 1012

Acquisition of high shot density blended seismic data: a WAZ sea trialAcquisition of high shot density blended seismic data: a WAZ sea trial
EAGE, 2014
Thomas Mensch | Damien Grenie | Risto Siliqi | Yunfeng Li
Summary
In this paper, we present the results of a high shot density sea trial recently performed in the Gulf of Mexico. The seismic data are acquired over an existing wide-azimuth and extra-long offsets survey. The higher shot density acquisition is achieved by reducing the shotpoint interval and taking full advantage of the continuous recording technology. The resulting blended seismic data are up to three times denser than the reference data without extra acquisition cost. Comparisons between blended and reference datasets show encouraging preliminary results.
Fully Sampled Wave-Fields: Soon a Reality?Fully Sampled Wave-Fields: Soon a Reality?
GEO, 2014
Jean-Paul Gruffeille | Salvador Rodriguez
Summary
Can you imagine the benefits the oil & gas industry would get if we were acquiring fully sampled wave fields (FSW)? Our industry has been measuring physical properties of the Earth that are continuous media by sampling in time and space and is therefore subjected to the sampling theory constraints. So, why discussing this nearly century old theorem, posed when the first seismic experiments were taking place? CGG decided to take the lead in this paradigm shift and created partnerships with several industry leaders, resulting in a number of innovative propositions. We will talk about some interesting outcome that can certainly improve oil recovery ratios.
P-wave AVAz Modeling:  A Haynesville case study P-wave AVAz Modeling: A Haynesville case study
CSEG, 2014
Jon Downton
Summary
For amplitude versus offset (AVO) studies it is common practice to perform forward modelling to understand whether the property of interest is detectable using AVO methods. Using this analogy, this paper argues that modeling the amplitude versus azimuth (AVAz) should be an important part of any AVAz study to detect fracturing. However, this is not the case largely due to the extra complexities of creating and dealing with the anisotropic model needed for these synthetics. This paper demonstrates a practical methodology to create a layered anisotropic model caused by fractures, using linear slip theory and available well log information. Modeling allows the interpreter to determine the magnitude and character of the expected azimuthal response and what azimuthal attributes might best detect the presence of fractures. The utility of this modeling is demonstrated as part of a Haynesville shale gas study.
Tomography of a velocity model and location of microseismic events with P, Sv and Sh wavesTomography of a velocity model and location of microseismic events with P, Sv and Sh waves
EAGE, 2014
Malgorzata Chmiel | Thomas Bardainne
Summary
This abstract demonstrates the feasibility of a joint use of P- and S-waves with surface monitoring network. Using the best quality microseismic events from a dataset recorded with three-component sensors; we first estimated an optimal velocity model through simulated annealing. We subsequently used it to detect and locate smaller events in a relative way. Our results show that the location - while using only P?waves - is poorly constrained and adding an S phase gives significant improvement.
3C Deghosting for Refraction Time-lapse Monitoring3C Deghosting for Refraction Time-lapse Monitoring
SEG, 2013
Kristof DeMeersman
Summary
Refraction time-lapse monitoring provides affordable areal measurements of reservoir changes using waves that travel from sources along a fast layer underlying the reservoir. When the waves exit the fast layer, they travel through the reservoir and propagate to the receivers, with corresponding arrival times depending on the state of the reservoir. For EOR, changes in the reservoir can be observed and interpreted from changes in these arrival times. Buried receivers benefit onshore seismic acquisition, in part because statics problems are less severe and because some decoupling from surface waves can be expected. Unfortunately, the statics problem is often just replaced by another problem ? surface ghosting with strong near-surface effects. For refraction data, which has lower fold than conventional surface seismic data, ghost removal can be even more important than for conventional seismic data. Using time-lapse data acquired at Peace River in Alberta, Canada, we carry out deghosting using a 3C wave field separation technique and show that the method significantly improves the time shift measurements. We then demonstrate its use in a processing workflow by generating an interpretable areal time-shift map for a new refraction time-lapse data set recorded in 2010/2011.
3C Deghosting for Refraction Time-lapse Monitoring3C Deghosting for Refraction Time-lapse Monitoring
EAGE, 2013
Kristof DeMeersman
Summary
In June to August of 2009, as part of an extensive investigation into methods for seismic monitoring at Peace River, Shell acquired four P-wave refraction data sets to monitor heavy oil thermal EOR at Peace River Pad 32 (Hansteen et al., 2010). Since then, three vintages with improved acquisition have been acquired in 2010 (two) and 2011 (one) and new processing technology has been deployed. While the original study of (Hansteen et al.) used only the vertical component signal we have found that using data from all components of 3C geophones allows the removal of receiver-side near-surface effects thus allowing the extraction of more reliable reservoir time lapse information. We present here a new method to perform receiver-side deghosting and assess its impact on the results. Our method uses data recorded on buried multi-component (3C) receiver arrays to isolate the up-going wave field and thereby removes any additive time-shift noise caused by time-variant changes in the near-surface layer above the receivers.
3C Deghosting for Refraction Time-lapse Monitoring3C Deghosting for Refraction Time-lapse Monitoring
CSEG, 2013
Kristof DeMeersman
Summary
Refraction time-lapse monitoring provides affordable areal measurements of reservoir changes using waves that travel from sources along a fast layer underlying the reservoir. When the waves exit the fast layer, they travel through the reservoir and propagate to the receivers, with corresponding arrival times depending on the state of the reservoir. For thermal EOR, changes in the reservoir can be observed and interpreted from changes in these arrival times. Buried receivers benefit onshore seismic acquisition, in part because statics problems are less severe and because some decoupling from surface waves can be expected. Unfortunately, the statics problem is often just replaced by another problem ? surface ghosting with strong near-surface effects. For refraction data, which is lower fold, ghost removal can be even more important than for conventional seismic data. At Peace River in Alberta, Canada, we carry out deghosting using a 3C wave field separation technique and show that the method significantly improves the time shift measurements. We then demonstrate its use in a processing workflow by generating a interpretable areal time-shift maps for a new refraction time-lapse data set recorded in 2010/2011.
3D VSP a useful tool for mining exploration3D VSP a useful tool for mining exploration
SAGA, 2013
Michel Denis | Eric Suaudeau
Summary
The 3DVSP technique becomes more popular with the emergence of multilevel 3-component borehole tools. The value of the information derived from VSP is not always well understood. In this paper we will present a case history of a joint surface and borehole seismic acquisition, with the goal to de-risk a shaft sinking location on a platinum mine. TD was about 650m and the VSP tool was 110m long. On surface a dense grid of receivers and vibrator source points were laid out in a 1.2 km radius circle centered on the well head. A 12-level 3C VSP digital tool was lowered in the borehole, in three successive depth positions. The surface 3D cube was processed and interpreted independently from the 3D VSP data. On a near target reflector, the surface data structural interpretation showed mainly a clear E/W fault, and additional sub-seismic lineaments of differing azimuths, difficult to identify in terms of fault. The 3D VSP image limited to a short radius around the borehole confirmed the fault/dyke nature of these lineaments, separating monocline compartments. As a consequence, the surface data were carefully re-interpreted and on the second structural images derived from two surface seismic reflectors and the near surface fault footprint from 3DVSP residual statics, a series of subtle faults were clearly assessed. Last, the few faults intersecting the borehole can be clearly recognized on the logs and the borehole radar logs. This case study demonstrates the added value of a joint interpretation of surface and borehole data in a decision-making process for shaft sinking.
12345678910...