scholarly journals Paleoenvironment of the Lower–Middle Cambrian Evaporite Series in the Tarim Basin and Its Impact on the Organic Matter Enrichment of Shallow Water Source Rocks

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 659
Author(s):  
Mingyang Wei ◽  
Zhidong Bao ◽  
Axel Munnecke ◽  
Wei Liu ◽  
G. William M. Harrison ◽  
...  
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Tarim Basin ◽  
Water Environment ◽  
Water Source ◽  
Major Elements ◽  
Source Rocks ◽  
Middle Cambrian ◽  
Sedimentary Environments ◽  
The Impact

Just as in deep-water sedimentary environments, productive source rocks can be developed in an evaporitic platform, where claystones are interbedded with evaporites and carbonates. However, the impact of the paleoenvironment on the organic matter enrichment of shallow water source rocks in an evaporite series has not been well explored. In this study, two wells in the central uplift of the Tarim Basin were systematically sampled and analyzed for a basic geochemical study, including major elements, trace elements, and total organic carbon (TOC), to understand the relationship between TOC and the paleoenvironmental parameters, such as paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity. The results show that the Lower–Middle Cambrian mainly developed in a fluctuating salinity, weak anoxic to anoxic, continuous dry and hot, and proper shallow water environment. The interfingering section of evaporites, carbonates, and claystones of the Awatag Fm. have higher paleoproductivity and higher enrichment of organic matter. Paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity jointly control the organic matter enrichment of shallow water source rocks in the evaporite series. The degree of enrichment of organic matter in shallow water source rocks first increases and then decreases with the increase in paleosalinity. All the samples with high content of organic matter come from the shallower environment of the Awatag Fm.

PETROLEUM POTENTIAL OF THE NEOPROTEROZOIC WESTERN OFFICER BASIN, WESTERN AUSTRALIA, BASED ON A SOURCE ROCK MODEL FROM EMPRESS-IA

1999 ◽  
Vol 39 (1) ◽  
pp. 322 ◽  
Author(s):  
G.M. Carlsen ◽  
S.N. Apak ◽  
K.A.R. Ghori K. Grey ◽  
M.K. Stevens
Keyword(s):  
Organic Matter ◽  
Western Australia ◽  
Depositional Environments ◽  
Source Rocks ◽  
Petroleum Potential ◽  
Organic Facies ◽  
Organic Growth ◽  
Rock Model ◽  
Depositional Controls ◽  
The Impact

The sedimentology, palaeontology and geochemistry of Neoproterozoic, organic-rich, clastic and related carbonate deposits in Western Australia provide new insights into the first-order depositional controls on hydrocarbon source rocks in the Neoproterozoic. Organic facies are correlated with depositional facies, revealing the impact of organic productivity and transport of organic rich sediments on the accumulation of organic matter in different depositional environments. Sedimentation is largely limited to ramp, platform, shoal, lagoon and sabkha environments.Growth of benthic organisms in the photic zone was the primary process controlling the production of organic matter in the ramp-shoreline system of the Kanpa Formation. Storms and floods were the primary mechanism for moving organic rich sediments into dysoxic and anoxic depositional environments. Variations in organic facies are indicated by: 1) changes in the palynomorph assemblages, particularly the increase in acritarchs within shallow-water ramp facies and cyanobacterial filaments in quiet-water sediments; 2) organic-rich laminae, containing abundant cyanobacterial filaments and mat material; and 3) the oxidation state of preserved organic remains.Periods of high organic growth rates or periods of mass mortality may have led to the development of an anoxic zone at the water-sediment interface. In the shoal and lagoonal settings, higher rates of clastic sediment dilution combined with oxygenated conditions resulted in lower TOC and hydrogen depleted organic facies.Condensed sections overlying stromatolitic dolomites represent the most effective organic facies of all of the potential source laminae sampled in Empress–IA. Most of the Officer Basin succession is currently within the oil-generating window and hydrocarbon shows encourage further exploration.

scholarly journals Petroleum source rocks of the Silurian deposits on the Chernov swell (Timan‑Pechora basin)

Georesursy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 12-20 ◽  
Author(s):  
Ivan S. Kotik ◽  
Tatyana V. Maidl ◽  
Olga S. Kotik ◽  
Natalia V. Pronina
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Carbonate Rock ◽  
Source Rocks ◽  
Pechora Basin ◽  
Low Concentrations ◽  
Oil Generation ◽  
Rock Eval ◽  
Source Of Information ◽  
Carbonate Deposits

Silurian source rocks are among the least studied in the Timan-Pechora basin. This is mainly due to their occurrence at great depths (3.0–4.5 km) and the limited penetration of this stratigraphic interval by wells. Another source of information is the outcrops of the Silurian, which are known in the eastern and northeastern parts of the Timan-Pechora basin. The studied section of the Silurian deposits is exposed on the Padimeityvis River, located on the Chernov swell in the northeastern part of the basin. This article is devoted to the study of Silurian source rocks based on the results of lithological, coal petrographic studies and geochemistry of organic matter. The studied section is composed of carbonate and clay-carbonate deposits formed in shallow-water shelf conditions. Most of the section, composed of microcrystalline and microcrystalline with bioclasts limestones, is characterized by low concentrations of organic matter (Corg is generally less than 0.3 %). Elevated Corg contents (up to 1.16 %) are characteristic of clay-carbonate rock varieties, which make up about 20 % of the section. Sediments with increased concentrations of organic matter were formed in isolated and deepened areas of the bottom of the shallow-water basin as a whole. Assessment of the catagenetic transformation based on Rock-Eval pyrolysis data, coal petrographic studies, and conodont color indices showed that organic matter reached the conditions of the middle-end of the main oil generation zone (gradation MC2‑MC3). The obtained geochemical characteristics (Corg, S2, HI), taking into account a certain level of organic matter maturity, indicate that the Silurian source rocks had an average hydrocarbon potential.

Quantifying the links between geochemical and geophysical properties of organic-rich carbonate mudrocks

2019 ◽  
Vol 38 (12) ◽  
pp. 914-922 ◽  
Author(s):  
Mita Sengupta ◽  
David Jacobi ◽  
Yazeed Altowairqi ◽  
Salma Al-Sinan
Keyword(s):  
Organic Matter ◽  
Seismic Response ◽  
Elastic Properties ◽  
Rock Physics ◽  
Source Rocks ◽  
Geochemical Data ◽  
Clear Understanding ◽  
Velocity Measurements ◽  
Geochemical Properties ◽  
The Impact

Source rocks possess complex heterogeneous matrices with soft organic matter, consisting mainly of kerogen, interspersed within a stiff inorganic mineral framework that varies in composition. There is not a clear understanding nor adequate knowledge of how geochemical properties influence the rock physics, especially when predicting a seismic response. While many attempts have been made to use seismic to empirically quantify these properties for the purpose of exploration, those attempts have often failed due to the complexity of the elastic properties of kerogen and the laminated geometry of the rock. This is due primarily to uncertainty over how these properties change with maturity as a result of burial and subsequent uplift. Therefore, knowledge of (1) the elastic properties of kerogen, (2) the amount and geometric distribution of organic matter within the rock matrix, and (3) the impact of kerogen maturity on its elastic properties is needed to predict a seismic response. An elastic property modeling method has been developed to address this challenge based on the integration of high-resolution microscopy, geochemical analysis, and velocity measurements. Using this approach, endmembers are obtained that allow for building rock-physics models that can predict elastic uncertainty from mineral heterogeneity and estimate the elastic properties of organic matter. Digital images, geochemical data, and velocity measurements coupled with maturity modeling suggest that bulk and shear softening of kerogen can help distinguish between maturity-induced seismic responses.

Occurrence of highly mature organic matter in marine black shale petroleum source rocks of basal cambrian from northern tarim basin, China

2004 ◽  
Vol 23 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Bingsong Yu ◽  
Dong Hailiang ◽  
Jianqiang Chen ◽  
Xiaolin Chen ◽  
Shiyou Liang
Keyword(s):  
Organic Matter ◽  
Black Shale ◽  
Tarim Basin ◽  
Source Rocks ◽  
Northern Tarim Basin

scholarly journals Organic Matter Accumulation Mechanism in the Lower Cambrian Strata from Well Luntan 1 in the Tarim Basin, NW China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qian Deng ◽  
Haizu Zhang ◽  
Haozhe Wang ◽  
Zhiwei Wei ◽  
Bin Cheng ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Tarim Basin ◽  
Enrichment Factors ◽  
Major And Trace Elements ◽  
Source Rocks ◽  
Drilling Depth ◽  
Nw China ◽  
High Productivity ◽  
Organic Matter Accumulation

A large amount of light crude oils have been found within 4000 to 7000 m deep strata of Cambrian, Ordovician, and Silurian reservoirs in the Tarim Basin, NW China. To enhance the understanding of parental materials of deep oils, a set of high-quality source rocks from the Yuertusi Formation in well Luntan 1 (maximum drilling depth of 8882 m) was studied in terms of their sedimentary condition and mechanism of organic matter enrichment. Total organic carbon (TOC) content, carbon isotope of kerogen (δ13Cker), and major and trace elements of the rocks from the Sinian Qigebulake, Cambrian Yuertusi, and Xiaoerbulake Formations in well Luntan 1 were analysed. The results showed that the δ13Cker value of the Yuertusi Formation barely changed with an average of -31.19‰. High TOC contents accompanied by enrichments of the bioessential trace elements, such as cadmium, chromium, copper, nickel, and zinc, occurred in the lower part of the Yuertusi Formation. Excess barium (Baxs) and phosphorus concentrations revealed high primary productivity during the deposition of the Yuertusi Formation. Moreover, variations in the enrichment factors of molybdenum, uranium, and vanadium and molybdenum-uranium covariation pattern indicated suboxic-anoxic conditions in the Qigebulake Formation, anoxic-euxinic conditions in the Yuertusi Formation, and suboxic-oxic conditions in the Xiaoerbulake Formation. The TOC contents were significantly correlated with the paleoproductivity and paleoredox parameters, indicating that high productivity and reducing conditions jointly controlled the organic matter accumulation and preservation in well Luntan 1.

scholarly journals Joint Inversion for Sound Speed Field and Moving Source Localization in Shallow Water

2019 ◽  
Vol 7 (9) ◽  
pp. 295 ◽  
Author(s):  
Dai ◽  
Li ◽  
Yang
Keyword(s):  
Kalman Filter ◽  
Shallow Water ◽  
Source Localization ◽  
Sound Speed ◽  
Joint Inversion ◽  
Source Parameters ◽  
Water Environment ◽  
Depth Range ◽  
Moving Source ◽  
The Impact

This paper develops a joint approach for time-evolving sound speed field (SSF) inversion and moving source localization in shallow water environment. The SSF is parameterized in terms of the first three empirical orthogonal function (EOF) coefficients. The approach treats both first three EOF coefficients and source parameters (e.g., source depth, range and speed) as state vectors of evolving with time, and a measurement vector that incorporates acoustic information via a vertical line array (VLA), and then the inversion problem is formulated in a state-space model. The processors of the extended Kalman filter (EKF) and ensemble Kalman filter (EnKF) are used to estimate the evolution of those six parameters. Simulation results verify the proposed approach, which enable it to invert the SSF and locate the moving source simultaneously. The root-mean-square-error (RMSE) is employed to evaluate the effectiveness of this proposed approach. The interfile comparison shows that the EnKF outperform the EKF. For the EnKF, the robustness of the approach under the sparse vertical array configuration is verified. Moreover, the impact of the source-VLA deployment on the estimation is also concerned.

Sway-Added Mass and Impact Load of a Large Tanker to a Jetty in Shallow Water

1983 ◽  
Vol 105 (1) ◽  
pp. 78-82
Author(s):  
C. H. Kim
Keyword(s):  
Kinetic Energy ◽  
Shallow Water ◽  
Impact Load ◽  
Analytical Data ◽  
Water Environment ◽  
Added Mass ◽  
Compression Phase ◽  
Practical Usefulness ◽  
Shallow Water Environment ◽  
The Impact

This paper presents a new simple technique for evaluating sway-added mass and the impact energy absorbed by fenders and dolphins when maneuvering a tanker to a jetty in a shallow water environment. The technique is based on the law of energy conservation, i.e., that the kinetic energy of the berthing ship is totally absorbed by the fenders during the compression phase. A time-averaged zero-frequency sway-added mass in shallow water is used in the evaluation of the kinetic energy. The theoretically calculated values of maximum deflection and fender loads are presented and compared with available experimental and analytical data. Discussion of the present method with respect to its degree of practical usefulness is given, while indicating problem areas.

scholarly journals Organic-Inorganic Geochemical Characteristics of the Upper Permian Pusige Formation in a High-Saline Lake Basin, Tarim Basin: Implications for Provenance, Paleoenvironments, and Organic Matter Enrichment

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-26
Author(s):  
Jingbin Wang ◽  
Zhiliang He ◽  
Dongya Zhu ◽  
Zhiqian Gao ◽  
Xiaowei Huang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Tarim Basin ◽  
Water Body ◽  
Tectonic Setting ◽  
Negative Relationship ◽  
Potential Effect ◽  
Source Rocks ◽  
Upper Permian ◽  
Lake Basin ◽  
Geochemical Parameters

The third member (M3) of the Upper Permian Pusige Formation is a prominent organic-rich lacustrine mudstone sequence within the Yecheng-Hetian Sag, Tarim Basin, hosting major petroleum resources. However, its depositional history and organic matter (OM) enrichment mechanism have received little attention. Therefore, various organic and inorganic geochemical analyses were performed on thirty-four core samples from the Well DW1, to elucidate their depositional paleoenvironments, provenance, and tectonic setting, as well as the controlling factors of OM enrichment. Results showed that the M3 mudstones are classified as poor- to fair-quality hydrocarbon source rocks with mature type II-III kerogen, considering their low organic geochemical parameters. Paleosalinity indexes (e.g., Beq, Sr/Ba, and B/Ga) indicated the typical high-saline lacustrine water body, in which redox state was the oxic-dysoxic as suggested by multiple indicators. Many paleoclimate and weathering proxies suggest a dominant semiarid condition and low weathering degree in the Yecheng-Hetian Sag, which led to that weathered felsic rocks from the West Kunlun Orogen to the southwest of basin were quickly transported into the lake basin. Detrital materials carrying nutrient elements finally promoted the development of relatively high paleoproductivity indicated by fairly high P/Ti and Ba/Al ratios. The negative relationship between P/Ti and total organic carbon (TOC) indicates that paleoproductivity was not the main controlling factor. The correlations among TOC and P/Ti and other multiple proxies suggest that the OM enrichment can be interpreted as both the “preservation model” and “dilution model.” Although the water body was relatively oxygen-riched, high sedimentation rate could largely shorten the exposure time of OM with oxygen, thus decreased the decomposition of OM. In particular, the high-saline, stratified lake water may also restrain the degradation of OM. Furthermore, detrital dilution exerted a potential effect on TOC abundances. On the basis of the above results, a developing model was established to decipher the formation mechanism of OM in these M3 mudstones.

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