Multiple seismic attribute analyses for determination of bottom simulating reflector of gas hydrate seismic data in the Ulleung Basin of Korea

2010 ◽  
Vol 31 (1-2) ◽  
pp. 121-132 ◽  
Author(s):  
Doan Huy Hien ◽  
Seonghyung Jang ◽  
Youngwan Kim
Keyword(s):  
Gas Hydrate ◽  
Seismic Data ◽  
Ulleung Basin ◽  
Seismic Attribute ◽  
Bottom Simulating Reflector ◽  
Attribute Analyses

Seismic attribute enhancement of weak and discontinuous gas hydrate bottom-simulating reflectors in the Pegasus Basin, New Zealand

2019 ◽  
Vol 7 (3) ◽  
pp. SG11-SG22 ◽  
Author(s):  
Heather Bedle
Keyword(s):  
New Zealand ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Seismic Data ◽  
Rock Physics ◽  
Stability Zone ◽  
Seismic Attribute ◽  
Rock Physics Modeling ◽  
Physics Modeling ◽  
Hydrate Stability

Gas hydrates in the oceanic subsurface are often difficult to image with reflection seismic data, particularly when the strata run parallel to the seafloor and in regions that lack the presence of a bottom-simulating reflector (BSR). To address and understand these imaging complications, rock-physics modeling and seismic attribute analysis are performed on modern 2D lines in the Pegasus Basin in New Zealand, where the BSR is not continuously imaged. Based on rock-physics and seismic analyses, several seismic attribute methods identify weak BSR reflections, with the far-angle stack data being particularly effective. Rock modeling results demonstrate that far-offset seismic data are critical in improving the imaging and interpretation of the base of the gas hydrate stability zone. The rock-physics modeling results are applied to the Pegasus 2009 2D data set that reveals a very weak seismic reflection at the base of the hydrates in the far-angle stack. This often-discontinuous reflection is significantly weaker in amplitude than typical BSRs associated with hydrates. These weak far-angle stack BSRs often do not appear clearly in full stack data, the most commonly interpreted seismic data type. Additional amplitude variation with angle (AVA) attribute analyses provide insight into identifying the presence of gas hydrates in regions lacking a strong BSR. Although dozens of seismic attributes were investigated for their ability to reveal weak reflections at the base of the gas hydrate stability zone, those that enhance class 2 AVA anomalies were most effective, particularly the seismic fluid factor attribute.

Estimation of gas hydrate and free gas saturation, concentration, and distribution from seismic data

Geophysics ◽  
2002 ◽  
Vol 67 (2) ◽  
pp. 582-593 ◽  
Author(s):  
Shaoming Lu ◽  
George A. McMechan
Keyword(s):  
Gas Hydrate ◽  
Seismic Data ◽  
Acoustic Impedance ◽  
Single Channel ◽  
Pore Space ◽  
Theoretical Models ◽  
Free Gas ◽  
Bottom Simulating Reflector ◽  
Saturation Concentration ◽  
Empirical Relations

Gas hydrates contain a major untapped source of energy and are of potential economic importance. The theoretical models to estimate gas hydrate saturation from seismic data predict significantly different acoustic/elastic properties of sediments containing gas hydrate; we do not know which to use. Thus, we develop a new approach based on empirical relations. The water‐filled porosity is calibrated (using well‐log data) to acoustic impedance twice: one calibration where gas hydrate is present and the other where free gas is present. The water‐filled porosity is used in a combination of Archie equations (with corresponding parameters for either gas hydrate or free gas) to estimate gas hydrate or free gas saturations. The method is applied to single‐channel seismic data and well logs from Ocean Drilling Program leg 164 from the Blake Ridge area off the east coast of North America. The gas hydrate above the bottom simulating reflector (BSR) is estimated to occupy ∼3–8% of the pore space (∼2–6% by volume). Free gas is interpreted to be present in three main layers beneath the BSR, with average gas saturations of 11–14%, 7–11%, and 1–5% of the pore space (6–8%, 4–6%, and 1–3% by volume), respectively. The estimated saturations of gas hydrate are very similar to those estimated from vertical seismic profile data and generally agree with those from independent, indirect estimates obtained from resistivity and chloride measurements. The estimated free gas saturations agree with measurements from a pressure core sampler. These results suggest that locally derived empirical relations between porosity and acoustic impedance can provide cost‐effective estimates of the saturation, concentration, and distribution of gas hydrate and free gas away from control wells.

scholarly journals Seismic Attribute Analysis of the Indicator for Gas Hydrate Occurrence in the Northwest Ulleung Basin, East Sea

2015 ◽  
Vol 76 ◽  
pp. 463-469 ◽  
Author(s):  
Kyoung Jin Kim ◽  
Bo Yeon Yi ◽  
Nyeon Keon Kang ◽  
Dong Geun Yoo
Keyword(s):  
Gas Hydrate ◽  
East Sea ◽  
Ulleung Basin ◽  
Seismic Attribute ◽  
Attribute Analysis

scholarly journals INDIKASI KEBERADAAN GAS HIDRAT PADA CEKUNGAN BUSUR MUKA SIMEULUE DAN POTENSINYA SEBAGAI SUMBER ENERGI MASA DEPAN

2016 ◽  
Vol 11 (3) ◽  
pp. 127
Author(s):  
Eko Triarso ◽  
Rainer Arief Troa
Keyword(s):  
Data Processing ◽  
Gas Hydrate ◽  
Seismic Data ◽  
Seismic Data Processing ◽  
Stability Zone ◽  
Bottom Simulating Reflector ◽  
Hydrate Stability

Gas hidrat merupakan gas metana (CH4) yang bersenyawa dengan air membentuk padatan kristal es pada temperatur dan tekanan tertentu sehingga pada kristal es ini mengandung molekul CH4 di dalam rongga molekul air (H2O). Keberadaan gas hidrat diharapkan dapat menjadi sumber energi baru masa depan. Cekungan Busur Muka (Cekungan) Simeulue memiliki kondisi tektonik dengan akumulasi sedimen laut dalam yang tebal sertadiindikasikan memiliki temperatur dan tekanan yang memungkinkan bagi terbentuknya zona stabilitas gas hidrat (Gas Hydrate Stability Zone-GHSZ).Tujuan penelitian adalah melakukan identifikasi keberadaan gas hidrat melalui interpretasi pada penampang seismik Cekungan Simeulue. Metodologi yang digunakan adalah melakukan pengolahan data seismik (seismic data processing) untuk menghasilkan penampang bawah permukaan dasar laut yang dapat memberikan gambaran struktur geologi dan perlapisan sedimen dengan cukup detail dan akurat. Karakteristik bottom simulating reflector(BSR) pada penampang seismik merupakan indikasi utama keberadaan gashidrat di dalam lapisan sedimen dasar laut. Data primer yang digunakan adalah hasil survei akuisisi seismik multichannel 2-Dpada 3 lintasan di Cekungan Simeulue. Survei seismik ini merupakan hasil kerjasama riset kelautan Indonesia-Jerman SEACAUSE II pada tahun 2006 di perairan barat Sumatera yang berhasil mendapatkan data pada 43 lintasan seismik. Berdasarkan hasil penelitian ini, BSR sebagai indikasi keberadaaan gas hidrat ditemukan pada 3 lintasan seismik pada Cekungan Simeulue yaitu lintasan BGR06-136, BGR06-137, dan BGR06-139 dengan karakteristik membentuk lensa, sejajar ataupun memotong horison perlapisan sedimen.

Seismic Attribute Analysis of the Indicators for the Occurrence of Gas Hydrate in the Northwestern Area of the Ulleung Basin, East Sea

2014 ◽  
Vol 17 (4) ◽  
pp. 216-230
Author(s):  
Kyoung Jin Kim ◽  
Bo Yeon Yi ◽  
Nyeon Keon Kang ◽  
Dong Geun Yoo ◽  
Kook Sun Shin ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
East Sea ◽  
Ulleung Basin ◽  
Seismic Attribute ◽  
Attribute Analysis ◽  
Northwestern Area

Acoustic impedance inversion and seismic reflection continuity analysis for delineating gas hydrate resources near the Mallik research sites, Mackenzie Delta, Northwest Territories, Canada

Geophysics ◽  
2009 ◽  
Vol 74 (5) ◽  
pp. B125-B137 ◽  
Author(s):  
Michael Riedel ◽  
Gilles Bellefleur ◽  
Stephanie Mair ◽  
Thomas A. Brent ◽  
Scott R. Dallimore
Keyword(s):  
Northwest Territories ◽  
Gas Hydrate ◽  
Seismic Data ◽  
Acoustic Impedance ◽  
Depth Range ◽  
3D Seismic ◽  
Mackenzie Delta ◽  
Seismic Attribute ◽  
Impedance Inversion ◽  
Acoustic Impedance Inversion

We combine acoustic impedance inversion of 3D seismic data, log-to-seismic correlation, and seismic attribute analyses to delineate gas-hydrate zones at the Mallik site, Mackenzie Delta, Northwest Territories, Canada. Well-log data define three distinct hydrate zones over a depth range of 890–1100 m. Synthetic seismic modeling indicates the base of the two deeper hydrate zones are prominent reflectors. The uppermost gas-hydrate zone correlates to seismic data with a lower degree of confidence. The extent and geometry of the two lower hydrate zones suggest that local geology plays a significant role in the lateral and vertical distribution of gas hydrate at Mallik. The reliability of the hydrate concentrations calculated from the inverted impedances isqualified by the match between original and synthetic seismic data to produce confidence maps for the two lower gas-hydrate-bearing intervals. A total in-place volume estimate of solid gas hydrate for an area of [Formula: see text] around well 5L-38 yields a value of approximately [Formula: see text] (equivalently, [Formula: see text] of gas). We further qualify our mapping of gas hydrates by some amount of continuous resource, defined as lateral continuity measured by seismic attribute similarity and sand-dominated rock. Using these attributes, the continuous amount of hydrate at Mallik is about half the in-place volume (i.e., [Formula: see text]). Elsewhere within the 3D seismic cube, the seismic impedance inversion yields evidence of potential gas-hydrate deposits near wells A-06 and P-59 at levels near the predicted base of the hydrate stability zone.

RESERVOIR PREDICTING METHOD BASED ON SEISMIC ATTRIBUTE ANALYSES: A CASE STUDY OF ES2x IN YONG 3 BLOCK OF YONG’AN AREA

2010 ◽  
Vol 29 (6) ◽  
pp. 95-102
Author(s):  
Jian GONG ◽  
Shumei XU ◽  
Yun MA ◽  
Jianguo YU ◽  
Jinduo WANG
Keyword(s):  
Seismic Attribute ◽  
Attribute Analyses

scholarly journals Prediction of Shale Gas Reservoirs Using Fluid Mobility Attribute Driven by Post-Stack Seismic Data: A Case Study from Southern China

2020 ◽  
Vol 11 (1) ◽  
pp. 219
Author(s):  
Jing Zeng ◽  
Alexey Stovas ◽  
Handong Huang ◽  
Lixia Ren ◽  
Tianlei Tang
Keyword(s):  
Shale Gas ◽  
Seismic Data ◽  
Spectral Decomposition ◽  
Southern China ◽  
Gas Reservoirs ◽  
Seismic Attribute ◽  
Longmaxi Formation ◽  
Shale Gas Reservoirs ◽  
The Sichuan Basin ◽  
Shale Reservoirs

Paleozoic marine shale gas resources in Southern China present broad prospects for exploration and development. However, previous research has mostly focused on the shale in the Sichuan Basin. The research target of this study is expanded to the Lower Silurian Longmaxi shale outside the Sichuan Basin. A prediction scheme of shale gas reservoirs through the frequency-dependent seismic attribute technology is developed to reduce drilling risks of shale gas related to complex geological structure and low exploration level. Extracting frequency-dependent seismic attribute is inseparable from spectral decomposition technology, whereby the matching pursuit algorithm is commonly used. However, frequency interference in MP results in an erroneous time-frequency (TF) spectrum and affects the accuracy of seismic attribute. Firstly, a novel spectral decomposition technology is proposed to minimize the effect of frequency interference by integrating the MP and the ensemble empirical mode decomposition (EEMD). Synthetic and real data tests indicate that the proposed spectral decomposition technology provides a TF spectrum with higher accuracy and resolution than traditional MP. Then, a seismic fluid mobility attribute, extracted from the post-stack seismic data through the proposed spectral decomposition technology, is applied to characterize the shale reservoirs. The application result indicates that the seismic fluid mobility attribute can describe the spatial distribution of shale gas reservoirs well without well control. Based on the seismic fluid mobility attribute section, we have learned that the shale gas enrich areas are located near the bottom of the Longmaxi Formation. The inverted velocity data are also introduced to further verify the reliability of seismic fluid mobility. Finally, the thickness map of gas-bearing shale reservoirs in the Longmaxi Formation is obtained by combining the seismic fluid mobility attribute with the inverted velocity data, and two favorable exploration areas are suggested by analyzing the thickness, structure, and burial depth. The present work can not only be used to evaluate shale gas resources in the early stage of exploration, but also help to design the landing point and trajectory of directional drilling in the development stage.

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