Northeast British Columbia Liard Basin: A seismic stratigraphy study

2020 ◽  
Vol 8 (3) ◽  
pp. T579-T588
Author(s):  
Jennifer Leslie-Panek ◽  
Margot McMechan ◽  
Fil Ferri
Keyword(s):  
British Columbia ◽  
Cross Section ◽  
Shale Gas ◽  
Seismic Data ◽  
Seismic Stratigraphy ◽  
Upper Devonian ◽  
Sediment Sources ◽  
Seismic Sequence Stratigraphy ◽  
High Level ◽  
Over Time

The Liard Basin is a highly prospective shale gas basin located in northeast British Columbia that is largely underrepresented in public literature. We used available-for-purchase 2D seismic data in the area to create a high-level, regional stratigraphic interpretation of the basin, providing the first seismically controlled overview of the basin structure and stratigraphy. The basin is characterized by two distinct, opposing wedges of sediment in the Mesozoic and Paleozoic sections: the Mesozoic with northeastward thinning and the Paleozoic with southwestward thinning. The wedging of the Upper Devonian-Lower Mississippian (Tournasian) section is dominated by multiple large packages of clinoforms, which progress into the basin from northeast to southwest and are predominantly seen in the seismic sequence stratigraphy. These distinct packages of clinoforms indicate changing sediment sources over time. In contrast, there are no clinoforms seen in the Mesozoic section, which may be a limitation of the orientation of the 2D seismic data that we used. Our result from the seismic interpretation is an updated interpretation of the Upper Devonian-Lower Mississippian stratigraphy of the Liard Basin, including an updated stratigraphic cross section for the area.

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.

Novel geometric classification of 3D seismic and its application to the Habshan clinoforms of Western Oman

2021 ◽  
Vol 40 (3) ◽  
pp. 186-192
Author(s):  
Thomas Krayenbuehl ◽  
Nadeem Balushi ◽  
Stephane Gesbert
Keyword(s):  
Sequence Stratigraphy ◽  
Seismic Data ◽  
Northwestern Part ◽  
Full Potential ◽  
Seismic Sequence ◽  
3D Seismic ◽  
Level Curve ◽  
Seismic Sequence Stratigraphy

The principles and benefits of seismic sequence stratigraphy have withstood the test of time, but the application of seismic sequence stratigraphy is still carried out mostly manually. Several tool kits have been developed to semiautomatically extract dense stacks of horizons from seismic data, but they stop short of exploiting the full potential of seismo-stratigraphic models. We introduce novel geometric seismic attributes that associate relative geologic age models with seismic geomorphological models. We propose that a relative sea level curve can be derived from the models. The approach is demonstrated on a case study from the Lower Cretaceous Kahmah Group in the northwestern part of Oman where it helps in sweet-spotting and derisking elusive stratigraphic traps.

Using Seismic Data to Predict Shale Pore Pressure and Overpressure Sweet Spots: A Case Study from the Lower Silurian Longmaxi Formation in Sichuan Basin, China

2021 ◽  
Author(s):  
Sheng Chen ◽  
Qingcai Zeng ◽  
Xiujiao Wang ◽  
Qing Yang ◽  
Chunmeng Dai ◽  
...  
Keyword(s):  
Prediction Model ◽  
Wave Velocity ◽  
Shale Gas ◽  
Seismic Data ◽  
P Wave ◽  
Formation Pressure ◽  
S Wave ◽  
P Wave Velocity ◽  
New Formation ◽  
Sweet Spots

Abstract Practices of marine shale gas exploration and development in south China have proved that formation overpressure is the main controlling factor of shale gas enrichment and an indicator of good preservation condition. Accurate prediction of formation pressure before drilling is necessary for drilling safety and important for sweet spots predicting and horizontal wells deploying. However, the existing prediction methods of formation pore pressures all have defects, the prediction accuracy unsatisfactory for shale gas development. By means of rock mechanics analysis and related formulas, we derived a formula for calculating formation pore pressures. Through regional rock physical analysis, we determined and optimized the relevant parameters in the formula, and established a new formation pressure prediction model considering P-wave velocity, S-wave velocity and density. Based on regional exploration wells and 3D seismic data, we carried out pre-stack seismic inversion to obtain high-precision P-wave velocity, S-wave velocity and density data volumes. We utilized the new formation pressure prediction model to predict the pressure and the spatial distribution of overpressure sweet spots. Then, we applied the measured pressure data of three new wells to verify the predicted formation pressure by seismic data. The result shows that the new method has a higher accuracy. This method is qualified for safe drilling and prediction of overpressure sweet spots for shale gas development, so it is worthy of promotion.

Rare earth element concentrations in Quaternary volcanic rocks of southwestern British Columbia

1984 ◽  
Vol 21 (6) ◽  
pp. 731-736 ◽  
Author(s):  
Nathan L. Green ◽  
Paul Henderson
Keyword(s):  
British Columbia ◽  
Earth Element ◽  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Lake Area ◽  
Calc Alkaline ◽  
Lower Light ◽  
The Individual ◽  
High Level ◽  
Ree Patterns

A suite of hy-normative hawaiites, ne-normative mugearite, and calc-alkaline andesitic rocks from the Garibaldi Lake area exhibits fractionated, slightly concave-upward REE patterns (CeN/YbN = 4.5–15), heavy REE contents about 5–10 times the chondritic abundances, and no Eu anomalies. It is unlikely that the REE patterns provide information concerning partial melting conditions beneath southwestern British Columbia because they have probably been modified substantially by upper crustal processes including crustal contamination and (or) crystal fractionation. The REE contents of the Garibaldi Lake lavas are not incompatible with previous interpretations that (1) the hawaiites have undergone considerable fractionation of olivine, plagioclase, and clinopyroxene; and (2) the individual andesitic suites were derived from separate batches of chemically distinct magma that evolved along different high-level crystallization trends. In general, however, the andesites are characterized by lower light REE contents than the basaltic andesites. These differences in LREE abundances may reflect different amounts of LREE-rich accessory phases, such as apatite, sphene, or allanite, assimilated from the underlying quartz diorites.

scholarly journals Enhancing main fermentation velocities in beer by the use of a membrane bioreactor – approach and preliminary results (membrane bioreactor beer)

2018 ◽  
Vol 14 (s1) ◽  
pp. 121-131 ◽  
Author(s):  
Lisa Stumpf ◽  
Stefan Schildbach
Keyword(s):  
Membrane Bioreactor ◽  
Membrane Technology ◽  
Gas Jet ◽  
Fermentation Processes ◽  
Preliminary Results ◽  
Module Design ◽  
Continuous Basis ◽  
Membrane Flux ◽  
High Level ◽  
Over Time

The potential of the most recent membrane technology is still unaccounted for in many respects. Combining fermentation with up-to-date membrane technology building a membrane bioreactor allows the adjustment of the cell count on a high level, increasing yield per volume and time. Applied to beer manufacturing, main fermentation times of less than 20 h seem possible, avoiding the disadvantages of already known accelerated fermentation processes operated on a continuous basis. Although module design was adapted and backwash procedure altered to gas-jet, maintaining a sufficient membrane flux over time still poses a major problem. Nevertheless, preliminary results in respect of beer quality look promising.

scholarly journals THE N.A. GOLOVKINSKY’S FUNDAMENTAL FACIAL LAW — PROBLEMATICS AND NEW HORIZONS

2018 ◽  
pp. 17-23
Author(s):  
V. P. ALEKSEEV ◽  
E. O. AMON
Keyword(s):  
Cognitive Process ◽  
Oil And Gas ◽  
Lateral Displacement ◽  
World View ◽  
Scientific Work ◽  
Seismic Stratigraphy ◽  
The West ◽  
New Horizons ◽  
The Law ◽  
Over Time

Famous Russian geologist N.A. Golovkinsky published 150 years ago an important scientific work, where the phenomenon of lateral  displacement (movement) of homogeneous lithological layers  («slide» over time) was asserted. This created the most significant  prerequisites for the fundamental facial law: the layers, lying nearby,  were formed in the same sequence vertically. The law was  formulated a little later by A.A. Inostrantsev, and later  «rediscovered» by J. Wal- ter. The ideas, developed by N.A.  Golovkinsky, subsequently found the application in the study of  geological cyclicity, and currently in the booming seismic  stratigraphy. The creative improvement and continuation of  theoretical positions  contained in the Golovkinsky’s work allowed to  advance a method of facially-cyclic analysis, which has been  success- fully used in the study of many coal-bearing strata, and is  currently used for coal-free deposits of the West Siberian oil and gas  basin. Methodically, they develop an understanding of causality and  correspond to the principles of synergetic world-view. The main  content of these ideas remains relevant in the light of new realities  of cognitive process (nonlin-ear science, endovision).

scholarly journals Co-occurrence of Hyperacusis Accelerates With Tinnitus Burden Over Time and Requires Medical Care

2021 ◽  
Vol 12 ◽  
Author(s):  
Fatma Refat ◽  
Jakob Wertz ◽  
Pauline Hinrichs ◽  
Uwe Klose ◽  
Hesham Samy ◽  
...  
Keyword(s):  
Medical Care ◽  
Global Burden ◽  
Neural Correlate ◽  
Hearing Thresholds ◽  
Causal Therapy ◽  
Advanced Therapies ◽  
High Level ◽  
Neural Gain ◽  
Over Time

Although tinnitus represents a major global burden, no causal therapy has yet been established. Ongoing controversies about the neuronal pathophysiology of tinnitus hamper efforts in developing advanced therapies. Hypothesizing that the unnoticed co-occurrence of hyperacusis and differences in the duration of tinnitus may possibly differentially influence the neural correlate of tinnitus, we analyzed 33 tinnitus patients without (T-group) and 20 tinnitus patients with hyperacusis (TH-group). We found crucial differences between the T-group and the TH-group in the increase of annoyance, complaints, tinnitus loudness, and central neural gain as a function of tinnitus duration. Hearing thresholds did not differ between T-group and TH-group. In the TH-group, the tinnitus complaints (total tinnitus score) were significantly greater from early on and the tinnitus intensity distinctly increased over time from ca. 12 to 17 dB when tinnitus persisted more than 5 years, while annoyance responses to normal sound remained nearly constant. In contrast, in the T-group tinnitus complaints remained constant, although the tinnitus intensity declined over time from ca. 27 down to 15 dB beyond 5 years of tinnitus persistence. This was explained through a gradually increased annoyance to normal sound over time, shown by a hyperacusis questionnaire. Parallel a shift from a mainly unilateral (only 17% bilateral) to a completely bilateral (100%) tinnitus percept occurred in the T-group, while bilateral tinnitus dominated in the TH-group from the start (75%). Over time in the T-group, ABR wave V amplitudes (and V/I ratios) remained reduced and delayed. By contrast, in the TH-group especially the ABR wave III and V (and III/I ratio) continued to be enhanced and shortened in response to high-level sound stimuli. Interestingly, in line with signs of an increased co-occurrence of hyperacusis in the T-group over time, ABR wave III also slightly increased in the T-group. The findings disclose an undiagnosed co-occurrence of hyperacusis in tinnitus patients as a main cause of distress and the cause of complaints about tinnitus over time. To achieve urgently needed and personalized therapies, possibly using the objective tools offered here, a systematic sub-classification of tinnitus and the co-occurrence of hyperacusis is recommended.

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