Using Zero-Offset VSP to Identify Interbed Multiples Generators, A Case Study from South Oman

2021 ◽  
Author(s):  
Othman Abderhman Al Badi ◽  
Majid Mohammed Al Battashi ◽  
Amani Mohammed Al Rubaiey ◽  
Elias Suleiman Al Kharusi

Abstract The presence of interbed multiples is a serious concern in surface seismic processing and interpretation. Its impact is huge especially if they are masking the desirable primary reflections such as the targeted reservoirs area. The conventional demultiple methodologies such as stacking, and deconvolution often fail to suppress all the interbed multiples. Therefore, a need for other measurement is crucial to eliminate the remaining ones (Burton and Lines, 1997). There are several approaches, data-driven or model-driven, currently available to predict the interbed multiples. However, they require an accurate identification of the multiple generators (Lesnikov and Owus, 2011). The identification of the origin of these multiples seems to be the most effective solutions to remove them, however it is not an easy task. The allure of Zero Offset Vertical Seismic Profiles (ZOVSPs) in having the receivers placed close to the subsurface horizons, allow both upgoing and downgoing wavefields to be recordable and separable. It's the combination of short window and long window deconvolution operators which are derived based on our knowledge of downgoing wavefield which help us to determine the multiples generators at their exact depths in the subsurface. This paper demonstrates how Zero offset VSP successfully helped to identify the major multiples generators in one of the exploratory fields in south Oman. These generators then used as an input to demultiple technique named as Extended Interbed Multiple Prediction (XIMP) that eliminates the multiples within surface seismic. As the result of the multiple elimination, the seismic to well tie tremendously improved and the reliability of the overall horizon interpretation is enhanced.

Geophysics ◽  
1993 ◽  
Vol 58 (6) ◽  
pp. 818-834 ◽  
Author(s):  
Frédéric Lefeuvre ◽  
Roger Turpening ◽  
Carol Caravana ◽  
Andrea Born ◽  
Laurence Nicoletis

Fracture or stress‐related shear‐wave birefringence (or azimuthal anisotropy) from vertical seismic profiles (VSPs) is commonly observed today, but no attempt is made to fit the observations with observed in‐situ fractures and velocities. With data from a hard rock (limestones, dolomites, and anhydrites) region of Michigan, fast and slow shear‐wave velocities have been derived from a nine‐component zero offset VSP and compared to shear‐wave velocities from two full waveform acoustic logs. To represent the shear‐wave birefringence that affects the shear wave’s vertical propagation, a propagator matrix technique is used allowing a local measurement independent of the overburden layers. The picked times obtained by using a correlation technique have been corrected in the birefringent regions before we compute the fast and slow velocities. Although there are some differences between the three velocity sets, there is a good fit between the velocities from the shear‐wave VSP and those from the two logs. We suspect the formations showing birefringence to be vertically fractured. To support this, we examine the behavior of the Stoneley wave on the full waveform acoustic logs in the formations. In addition, we analyze the borehole televiewer data from a nearby well. There is a good fit between the fractures seen from the VSP data and those seen from the borehole.


1990 ◽  
Vol 80 (4) ◽  
pp. 832-856
Author(s):  
Hsi-Ping Liu

Abstract Impulse responses including near-field terms have been obtained in closed form for the zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an anelastic half-space. The method is based on the correspondence principle. Through transformation of variables, the Fourier transform of the elastic impulse response is put in a form such that the Fourier transform of the corresponding anelastic impulse response can be expressed as elementary functions and their definite integrals involving distance, angular frequency, phase velocities, and attenuation factors. These results are used for accurate calculation of shear-wave arrival rise times of synthetic seismograms needed for data interpretation of anelastic-attenuation measurements in near-surface sediment.


Geophysics ◽  
1994 ◽  
Vol 59 (10) ◽  
pp. 1500-1511 ◽  
Author(s):  
Jakob B. U. Haldorsen ◽  
Douglas E. Miller ◽  
John J. Walsh

We describe a technique for performing optimal, least‐squares deconvolution of vertical seismic profile (VSP) data. The method is a two‐step process that involves (1) estimating the source signature and (2) applying a least‐squares optimum deconvolution operator that minimizes the noise not coherent with the source signature estimate. The optimum inverse problem, formulated in the frequency domain, gives as a solution an operator that can be interpreted as a simple inverse to the estimated aligned signature multiplied by semblance across the array. An application to a zero‐offset VSP acquired with a dynamite source shows the effectiveness of the operator in attaining the two conflicting goals of adaptively spiking the effective source signature and minimizing the noise. Signature design for seismic surveys could benefit from observing that the optimum deconvolution operator gives a flat signal spectrum if and only if the seismic source has the same amplitude spectrum as the noise.


GeoArabia ◽  
1998 ◽  
Vol 3 (2) ◽  
pp. 209-226
Author(s):  
Mohammed N. Alfara ◽  
Edgardo L. Nebrija ◽  
Michael D. Ferguson

ABSTRACT The giant Shaybah field, situated in the northeastern Rub’ Al-Khali Desert in Saudi Arabia, was discovered in 1968. 2-D seismic and well control were used at the time to delineate the field. A 3-D seismic program was launched in 1993 to develop a detailed geological picture of the field. Over 120 million seismic traces, covering an area of about 1,100 square kilometers, were acquired in flat sabkhas and high sand dunes. The dunes, exceeding 200 meters in height in places, posed a severe statics correction problem. Up to 200 milliseconds of time correction was sometimes applied to the seismic traces in order to compensate for sand-related statics. Also, as verified by vertical seismic profiles, the reservoir level was severely obscured by strong multiples. In addition to complex topography and multiples, the 3-D structural seismic interpretation had to overcome two further problems. First, the lithology of the gas-capped Shu’aiba reservoir consists predominantly of carbonates which are sealed by a denser, compacted shale. The decrease in density and increase in velocity, at the top of the Shu’aiba reservoir, result in a weak reflection. Second, the top of the Shu’aiba reservoir undulates as a result of rudist build-ups and therefore is not conformable with its base. For these reasons, the top of the Shu’aiba reservoir cannot be mapped as a “phantom” of the much better reflection from the base of the reservoir. To resolve the uncertainties described above, borehole seismic measurements (specifically offset and zero-offset vertical seismic profiles in vertical wells) were incorporated. These additional measurements provided the required calibration of the seismic, and hence the validation of the structural interpretation. These borehole surveys continue to serve as a reference for on-going efforts to further improve the data quality using more advanced processing techniques.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2085
Author(s):  
Xue-Bo Jin ◽  
Ruben Jonhson Robert RobertJeremiah ◽  
Ting-Li Su ◽  
Yu-Ting Bai ◽  
Jian-Lei Kong

State estimation is widely used in various automated systems, including IoT systems, unmanned systems, robots, etc. In traditional state estimation, measurement data are instantaneous and processed in real time. With modern systems’ development, sensors can obtain more and more signals and store them. Therefore, how to use these measurement big data to improve the performance of state estimation has become a hot research issue in this field. This paper reviews the development of state estimation and future development trends. First, we review the model-based state estimation methods, including the Kalman filter, such as the extended Kalman filter (EKF), unscented Kalman filter (UKF), cubature Kalman filter (CKF), etc. Particle filters and Gaussian mixture filters that can handle mixed Gaussian noise are discussed, too. These methods have high requirements for models, while it is not easy to obtain accurate system models in practice. The emergence of robust filters, the interacting multiple model (IMM), and adaptive filters are also mentioned here. Secondly, the current research status of data-driven state estimation methods is introduced based on network learning. Finally, the main research results for hybrid filters obtained in recent years are summarized and discussed, which combine model-based methods and data-driven methods. This paper is based on state estimation research results and provides a more detailed overview of model-driven, data-driven, and hybrid-driven approaches. The main algorithm of each method is provided so that beginners can have a clearer understanding. Additionally, it discusses the future development trends for researchers in state estimation.


2021 ◽  
Vol 13 (3) ◽  
pp. 1193
Author(s):  
Anna Podara ◽  
Dimitrios Giomelakis ◽  
Constantinos Nicolaou ◽  
Maria Matsiola ◽  
Rigas Kotsakis

This paper casts light on cultural heritage storytelling in the context of interactive documentary, a hybrid media genre that employs a full range of multimedia tools to document reality, provide sustainability of the production and successful engagement of the audience. The main research hypotheses are enclosed in the statements: (a) the interactive documentary is considered a valuable tool for the sustainability of cultural heritage and (b) digital approaches to documentary storytelling can provide a sustainable form of viewing during the years. Using the Greek interactive documentary (i-doc) NEW LIFE (2013) as a case study, the users’ engagement is evaluated by analyzing items from a seven-year database of web metrics. Specifically, we explore the adopted ways of the interactive documentary users to engage with the storytelling, the depth to which they were involved along with the most popular sections/traffic sources and finally, the differences between the first launch period and latest years were investigated. We concluded that interactivity affordances of this genre enhance the social dimension of cultural, while the key factors for sustainability are mainly (a) constant promotion with transmedia approach; (b) data-driven evaluation and reform; and (c) a good story that gathers relevant niches, with specific interest to the story.


2021 ◽  
Vol 296 ◽  
pp. 126242
Author(s):  
Oliver J. Fisher ◽  
Nicholas J. Watson ◽  
Laura Porcu ◽  
Darren Bacon ◽  
Martin Rigley ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document