scholarly journals FischerLab: An Application for Generating Fischer Plots and Dynamic Fischer Plots from Wireline Well-Logs and Stratigraphic Data

Earth ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 36-48
Author(s):  
Adewale Amosu ◽  
Mohamed Imsalem ◽  
Anne Raymond ◽  
Yuefeng Sun
Keyword(s):  
Cyclic Carbonate ◽  
Well Logs ◽  
Relative Depth ◽  
The Bahamas ◽  
Direct Construction ◽  
Cycle Number ◽  
Great Bahama Bank ◽  
Central Texas ◽  
Wireline Logs ◽  
Glen Rose Formation

Fischer plots are a technique that is used to graph changes in accommodation in cyclic carbonate successions. They typically depict the cumulative departure from the average cycle thickness as a function of the cycle number or stratigraphic depth. Many applications of Fischer plots focus on their construction from exposed cyclic carbonate successions. No published programs allow the direct construction of Fischer plots from digital wireline well-logs or dynamic presentations of Fischer plots. Here, we introduce a program known as FischerLab, which facilitates the generation and analysis of Fischer plots. In addition to accepting interpreted stratigraphic data input, FischerLab facilitates the interpretation of digital wireline logs for the generation of Fischer plots in cycle and depth domains, as well as in a dynamic evolving cycle and relative depth domain from an easy-to-use interface. The dynamic construction facilitates the correlation of specific stratigraphic packages to parts of the accommodation cycle while simultaneously tracking the locus of the mean subsidence vector. We demonstrate the use of FischerLab on data derived from the carbonate succession outcrops of the Al-Athrun Formation, Libya, and the Glen Rose Formation, Central Texas, USA, as well as on wireline well-log data from the Western Great Bahama Bank, the Bahamas.

scholarly journals Improved well logs clustering algorithm for shale gas identification and formation evaluation

2021 ◽  
Author(s):  
N. P. Szabó ◽  
B. A. Braun ◽  
M. M. G. Abdelrahman ◽  
M. Dobróka
Keyword(s):  
Cluster Analysis ◽  
Shale Gas ◽  
Clustering Algorithm ◽  
Traditional Approach ◽  
Harmful Effect ◽  
Weighted Average ◽  
Well Logs ◽  
Organic Carbon Content ◽  
Wireline Logs ◽  
Most Frequent Value

AbstractThe identification of lithology, fluid types, and total organic carbon content are of great priority in the exploration of unconventional hydrocarbons. As a new alternative, a further developed K-means type clustering method is suggested for the evaluation of shale gas formations. The traditional approach of cluster analysis is mainly based on the use of the Euclidean distance for grouping the objects of multivariate observations into different clusters. The high sensitivity of the L2 norm applied to non-Gaussian distributed measurement noises is well-known, which can be reduced by selecting a more suitable norm as distance metrics. To suppress the harmful effect of non-systematic errors and outlying data, the Most Frequent Value method as a robust statistical estimator is combined with the K-means clustering algorithm. The Cauchy-Steiner weights calculated by the Most Frequent Value procedure is applied to measure the weighted distance between the objects, which improves the performance of cluster analysis compared to the Euclidean norm. At the same time, the centroids are also calculated as a weighted average (using the Most Frequent Value method), instead of applying arithmetic mean. The suggested statistical method is tested using synthetic datasets as well as observed wireline logs, mud-logging data and core samples collected from the Barnett Shale Formation, USA. The synthetic experiment using extremely noisy well logs demonstrates that the newly developed robust clustering procedure is able to separate the geological-lithological units in hydrocarbon formations and provide additional information to standard well log analysis. It is also shown that the Cauchy-Steiner weighted cluster analysis is affected less by outliers, which allows a more efficient processing of poor-quality wireline logs and an improved evaluation of shale gas reservoirs.

Mimicking the process of manual sequence stratigraphy well correlation

2021 ◽  
pp. 1-65
Author(s):  
Huijing Fang ◽  
Yihuai Lou ◽  
Bo Zhang ◽  
Huaimin Xu ◽  
Man Lu
Keyword(s):  
Euclidean Distance ◽  
Well Logs ◽  
Stratigraphic Correlation ◽  
Time Warping ◽  
Error Matrix ◽  
Stratigraphic Model ◽  
Wireline Logs ◽  
Well Correlation ◽  
Dynamic Time ◽  
Error Computation

Stratigraphic correlation of well logs is based on interactive, interpreter-based pattern recognition. A skilled interpreter identifies similar patterns (such as upward fining and coarsening) in user-defined well sections and links them using either a conscious or subconscious stratigraphic model. This manual stratigraphic correlation of numerous wells in mature fields can be both time consuming and error prone. To expedite the process of stratigraphic correlation, we perform the semi-automatic stratigraphic correlation of wireline logs from multiple wells using the Improved Dynamic Time Warping (IDTW). The IDTW employs semblance, which compares the shape of the well logs, to replace the Euclidean distance in the pairwise error computation. The resulting error matrix is compatible with the lateral nonstationary variation of well logs in the same formation. The workflow begins with interpreting stratigraphic well tops on user-defined well sections that is similar to current process of stratigraphy analysis. The interpreted wells are then treated as reference wells to aid in interpreting well tops for other wells. Necessary manual interventions are incorporated during the process of the semi-automatic stratigraphic correlation. We applied the proposed method to two experimental fields: a sand-rich reservoir and a mud-rich reservoir. The applications illustrate that the proposed method performs well in aggradational strata and successfully predicts the discontinuities with manual interventions.

The Precipitation of Calcium Carbonate on the Great Bahama Bank

1933 ◽  
Vol 70 (10) ◽  
pp. 455-466 ◽  
Author(s):  
Maurice Black
Keyword(s):  
New Jersey ◽  
Calcium Carbonate ◽  
Water Samples ◽  
Chlorine Content ◽  
The Bahamas ◽  
Chemical Laboratory ◽  
Great Bahama Bank ◽  
Andros Island ◽  
The University ◽  
Total Salinity

In the spring of 1930 the International Expedition to the Bahamas made several traverses over the shoals west of Andros Island in order to study the sedimentation of calcium carbonate in this region, and along three of these lines water samples were collected at regular intervals. The chlorine content of each of these samples was determined by the author in the Chemical Laboratory at the University of Princeton, New Jersey, and the total salinity was obtained by calculation.

scholarly journals A Synopsis of the Bahamas Drilling Project: Results from Two Deep Core Borings Drilled on the Great Bahama Bank

1997 ◽  
Author(s):  
G.P. Eberli ◽  
P.K. Swart ◽  
D.F. McNeill ◽  
J.A.M. Kenter ◽  
F.S. Anselmetti ◽  
...  
Keyword(s):  
The Bahamas ◽  
Great Bahama Bank ◽  
Drilling Project

Integrating Wireline Logs and Seismic Data to Analyse The Facies snd Paleogeography of Tanjung Formation, Barito Basin, South Kalimantan

2020 ◽  
Author(s):  
E. A. Rosa
Keyword(s):  
Sequence Stratigraphy ◽  
Seismic Data ◽  
Depositional Environment ◽  
Well Logs ◽  
Facies Distribution ◽  
Sequence Stratigraphic ◽  
Core Data ◽  
Wireline Logs ◽  
Depositional Models

The study area is physiographically part of the Barito Basin, South Kalimantan (Van Bemmelen, 1949). 2D seismic data along with well logs from three wells, biostratigraphy data from two wells, and core data are utilized to do an integrated sequence stratigraphy. Petrography data from the equivalent formation at well-X from the study area is also used to support the evaluation. This study was to determine lithology facies and depositional environment based on several key maps: Sand Shale Ratio (SSR), Isopach, and Paleogeographic Maps. After that, seismically-supported sequence stratigraphy was applied to vertically and laterally subdivide the facies distribution and paleogeography into two depositional models based on the following key sequence-stratigraphic markers: (1) Sequence Boundary (SB)-1 to SB-2 that show regressive succession, and (2) SB-2 to Top Tanjung Formation that reflects transgressive phase.

Redescription of the milliped Amphelictogon subterraneus bahamiensis Chamberlin, 1918, with an assessment of the family Chelodesmidae in the Bahamas (Polydesmida: Leptodesmidea)

Zootaxa ◽  
2003 ◽  
Vol 180 (1) ◽  
pp. 1 ◽  
Author(s):  
ROWLAND M. SHELLEY
Keyword(s):  
New World ◽  
The Bahamas ◽  
Great Bahama Bank ◽  
The Family ◽  
Land Mass ◽  
Continuous Population ◽  
First Time

The milliped Amphelictogon subterraneus bahamiensis Chamberlin, 1918, the only representative of the family Chelodesmidae in the Bahamas and the only one in the New World occurring in part north of the Tropic of Cancer, is recorded from Eleuthera Island in addition to published localities from Andros and Cat Islands, Bahamas, and Cayo Coco, Cuba, where it is common. A redescription in English is provided along with gonopod drawings in medial and lateral views; a female cyphopod is illustrated for the first time. The populations on these three Bahamian islands probably represent isolated fragments of a once continuous population on the Pleistocene “super-island” on Great Bahama Bank, which in turn likely originated through rafting from the area of Cuba that now includes Cayo Coco. Investigations are needed to learn whether the species still survives on Andros, Eleuthera, and Cat islands, and whether additional populations occur on other islands that were once joined in the Pleistocene land mass.

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