scholarly journals Aromatic Hydrocarbons as Indicators of Maturation and Source: Correlative Geochemical Evaluation of Commingled Niger Delta Crude Oils

2020 ◽  
Vol 4 (2) ◽  
pp. 1-9
Author(s):  
Onyema MO
Keyword(s):  
Crude Oil ◽  
Aromatic Hydrocarbons ◽  
Niger Delta ◽  
Higher Plants ◽  
Source Rocks ◽  
Crude Oils ◽  
Relative Distribution ◽  
Geochemical Parameters ◽  
The Individual ◽  
Maturity Parameters

Two Niger Delta crude oils from Rivers and Delta States (samples A and F) and their compositional mixtures (samples B, C, D and E) where evaluated using a range of geochemical parameters derived from aromatic hydrocarbons and aromatic sulphur compounds to determine their source and maturity. The relative distribution of various plant markers in crude oil samples A and F which were retained in their compositional mixes suggests the contribution of angiosperm higher plants and coniferous higher plants to the source rocks that generated the crude oils. The various maturity parameters computed for the oil samples revealed that both the Rivers and Delta crude oils lie in the high maturity state with sample F significantly more matured than sample A. All alkynaphthalene maturity parameters suggested a peak to late oil generation window for the crude oil samples except the methyl naphthalene ratio (MNR) whose maturity sequence lacks sufficient variation to distinguish maturity differences in the crude oil samples. The maturity characters of TNR-1 and TNR-2 (trimethylnaphthalene ratio) showed a strong correlation between the individual crude oil samples and their mixtures. However, all the other maturity parameters showed moderate or weak correlation between the individual crude oil samples and their mixtures.

scholarly journals Light Hydrocarbon Geochemistry: Insight into Mississippian Crude Oil Sources from the Anadarko Basin, Oklahoma, USA

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ibrahim Atwah ◽  
Stephen Sweet ◽  
John Pantano ◽  
Anthony Knap
Keyword(s):  
Crude Oil ◽  
Fluid Dynamic ◽  
Northern Region ◽  
Source Rocks ◽  
Crude Oils ◽  
Variable Degree ◽  
Woodford Shale ◽  
Reservoir Water ◽  
Water Washing ◽  
Geochemical Parameters

The Mississippian limestone is a prolific hydrocarbon play in the northern region of Oklahoma and the southern part of Kansas. The Mississippian reservoirs feature variations in produced fluid chemistry usually explained by different possible source rocks. Such chemical variations are regularly obtained from bulk, molecular, and isotopic characteristics. In this study, we present a new geochemical investigation of gasoline range hydrocarbons, biomarkers, phenols, and diamondoids in crude oils produced from Mississippian carbonate and Woodford Shale formations. A set of oil samples was examined for composition using high-performance gas-chromatography and mass-spectrometry techniques. The result shows a distinct geochemical fingerprint reflected in biomarkers such as the abundance of extended tricyclic terpanes, together with heptane star diagrams, and diamantane isomeric distributions. Such compounds are indicative of the organic matter sources and stages of thermal maturity. Phenolic compounds varied dramatically based on geographic location, with some oil samples being depleted of phenols, while others are intact. Based on crude oil compositions, two possible source rocks were identified including the Woodford Shale and Mississippian mudrocks, with a variable degree of mixing reported. Variations in phenol concentrations reflect reservoir fluid dynamic and water interactions, in which oils with intact phenols are least affected by water-washing conversely and crude oils depleted in phenols attributed to reservoir water-washing. These geochemical parameters shed light into petroleum migration within Devonian-Mississippian petroleum systems and mitigate geological risk in exploring and developing petroleum reservoirs.

scholarly journals Effective source rock selection and oil–source correlation in the Western Slope of the northern Songliao Basin, China

2021 ◽  
Vol 18 (2) ◽  
pp. 398-415
Author(s):  
He Bi ◽  
Peng Li ◽  
Yun Jiang ◽  
Jing-Jing Fan ◽  
Xiao-Yue Chen
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Thermal Evolution ◽  
Songliao Basin ◽  
Source Rocks ◽  
Crude Oils ◽  
Western Slope ◽  
Geochemical Parameters ◽  
Group I ◽  
Oil Source

AbstractThis study considers the Upper Cretaceous Qingshankou Formation, Yaojia Formation, and the first member of the Nenjiang Formation in the Western Slope of the northern Songliao Basin. Dark mudstone with high abundances of organic matter of Gulong and Qijia sags are considered to be significant source rocks in the study area. To evaluate their development characteristics, differences and effectiveness, geochemical parameters are analyzed. One-dimensional basin modeling and hydrocarbon evolution are also applied to discuss the effectiveness of source rocks. Through the biomarker characteristics, the source–source, oil–oil, and oil–source correlations are assessed and the sources of crude oils in different rock units are determined. Based on the results, Gulong and Qijia source rocks have different organic matter primarily detrived from mixed sources and plankton, respectively. Gulong source rock has higher thermal evolution degree than Qijia source rock. The biomarker parameters of the source rocks are compared with 31 crude oil samples. The studied crude oils can be divided into two groups. The oil–source correlations show that group I oils from Qing II–III, Yao I, and Yao II–III members were probably derived from Gulong source rock and that only group II oils from Nen I member were derived from Qijia source rock.

scholarly journals Oil chemometrics and geochemical correlation in the Weixinan Sag, Beibuwan Basin, South China Sea

2020 ◽  
Vol 38 (6) ◽  
pp. 2695-2710
Author(s):  
Yao-Ping Wang ◽  
Xin Zhan ◽  
Tao Luo ◽  
Yuan Gao ◽  
Jia Xia ◽  
...  
Keyword(s):  
Source Rock ◽  
Principal Component ◽  
Sedimentary Basins ◽  
Oil Field ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Crude Oils ◽  
Geochemical Parameters ◽  
Group I ◽  
Oil Source

The oil–oil and oil–source rock correlations, also termed as geochemical correlations, play an essential role in the construction of petroleum systems, guidance of petroleum exploration, and definition of reservoir compartments. In this study, the problems arising from oil–oil and oil–source rock correlations were investigated using chemometric methods on oil and source rock samples from the WZ12 oil field in the Weixinan sag in the Beibuwan Basin. Crude oil from the WZ12 oil field can be classified into two genetic families: group A and B, using multidimensional scaling and principal component analysis. Similarly, source rocks of the Liushagang Formation, including its first, second, and third members, can be classified into group I and II, corresponding to group B and A crude oils, respectively. The principle geochemical parameters in the geochemical correlation for the characterisation and classification of crude oils and source rocks were 4MSI, C27Dia/C27S, and C24 Tet/C26 TT. This study provides insights into the selection of appropriate geochemical parameters for oil–oil and oil–source rock correlations, which can also be applied to other sedimentary basins.

scholarly journals Petroleum Geochemistry Regional Study of Murzuq Basin: Insights from Biomarkers Characteristic, Stable Carbon Isotope and Environmental Characterization

2020 ◽  
Vol 4 (1) ◽  
pp. 1-14
Author(s):  
Aboglila S
Keyword(s):  
Carbon Isotope ◽  
Vitrinite Reflectance ◽  
Stable Carbon Isotope ◽  
Source Rocks ◽  
Crude Oils ◽  
Type I ◽  
Stable Carbon ◽  
Potential Source ◽  
Geochemical Parameters ◽  
Rock Eval

This search aims to apply developed geochemical methods to a number of oils and source rock extracts to better establish the features of ancient environments that occurred in the Murzuq basin. Geochemical and geophysical approaches were used to confirm further a source contribution from other Paleozoic formations to hydrocarbon accumulations in the basin. One hundred and forty rock units were collected from B1-NC151, D1-NC174, A1-NC 76, D1-NC 151, F1-NC58, A1-NC 186, P1-NC 101, D1-NC 58, H1-NC58 and A1-NC58 wells. Seven crude oils were collocated A1-NC186, B1-NC186, E2-NC101, F3-NC174, A10-NC115, B10-NC115 and H10-NC115 wells. A geochemical assessment of the studied rocks and oils was done by means of geochemical parameters of total organic carbon (TOC), Rock-Eval analysis, detailed-various biomarkers and stable carbon isotope. The TOC values from B1-NC151 range 0.40% to 8.5%, A1-NC186 0.3% and 1.45, A1-NC76 0.39% to 0.74%, D1-NC151 0.40% to 2.00% to F1-NC58 0.40% to 1.12%. D1_NC174 0.30% to 10 %, P1-NC101 0.80% to 1.35%, D1-NC58 0.5% to 1.10%, H1-NC58 0.20% to 3.50%, A1-NC58 0.40% to 1.60%. The categories of organic matter from rock-eval pyrolysis statistics point to that type II kerogen is the main type, in association with type III, and no of type I kerogen recognized. Vitrinite reflectance (%Ro), Tmax and Spore colour index (SCI) as thermal maturity parameters reflect that the measured rock units are have different maturation levels, ranging from immature to mature sources. acritarchs distribution for most samples could be recognized and Palynomorphs are uncommon. Pristane to phytane ratios (> 1) revealed marine shale to lacustrine of environmental deposition. The Stable carbon isotope ( δ 13 C) values of seven rock-extract samples are -30.98‰ and -29.14‰ of saturates and -29.86‰ to -28.37‰ aromatic fractions. The oil saturate hydrocarbon fractions range between -29.36‰ to -28.67‰ and aromatic are among -29.98 ‰ to -29.55 ‰. The δ 13 C data in both rock extractions and crude oils are closer to each other, typical in sign of Paleozoic age. It is clear that the base of Tanezzuft Formation (Hot shale) is considered the main source rocks. The Devonian Awaynat Wanin Formation as well locally holds sufficient oil prone kerogen to consider as potential source rocks. Ordovician Mamuniyat Formation shales may poorly contain oil prone kerogen to be addressed in future studies. An assessment of the correlations between the oils and potential source rocks and between the oils themselves indicated that most of the rocks extracts were broadly similar to most of the oils and supported by carbon stable isotope analysis results.

scholarly journals An organic geochemical correlation study of some drmno depresssion crude oils (southern part of the Pannonian Basin, Yugoslavia)

2001 ◽  
Vol 66 (5) ◽  
pp. 297-308 ◽  
Author(s):  
B. Jovancicevic ◽  
H. Wehner ◽  
G. Scheeder ◽  
D. Plecas ◽  
M. Ercegovac ◽  
...  
Keyword(s):  
Pannonian Basin ◽  
Correlation Study ◽  
Oil Fields ◽  
Source Rocks ◽  
Crude Oils ◽  
Reservoir Rocks ◽  
Correlation Studies ◽  
Geochemical Parameters ◽  
Reliable Source

The results of an investigation of crude oils originating from the Sirakovo and Bradarac-Maljurevac localities (southern part of the Pannonian Basin) are reported in this paper. The aim was to estimate the organic geochemical similarity of the crude oils from the Drmno (Kostolac) depression oil fields. The nine selected samples originated from reservoir rocks of various depths. Reliable source and organic geochemical maturation parameters served as the basis for the correlation studies. The similar origin of the investigated Drmno depression crude oils was corroborated, characterized by a significant participation of terrestrial precursor biomass. They were shown to be of relatively low maturity and to have been formed during the earlier stages of the diagenetic-catagenetic sequence of processes leading to the formation of crude oils, most probably in source rocks ofTertiary age, corresponding to vitrinite reflectances between Ro = 0.70 % and Ro = 0.80 %. The crude oils from Bradarac-Maljurevac seemed to be somewhat less homogeneous with respect to organic geochemical parameters compared to Sirakovo crude oils.

RECONSTRUCTING THE GEOLOGICAL HISTORY OF AUSTRALIAN CRUDE OILS USING AROMATIC HYDROCARBONS

2000 ◽  
Vol 40 (1) ◽  
pp. 283 ◽  
Author(s):  
B.G.K. van Aarssen ◽  
R. Alexander ◽  
R.I. Kagi
Keyword(s):  
Thermal Stress ◽  
Crude Oil ◽  
Internal Consistency ◽  
Aromatic Hydrocarbons ◽  
Crude Oils ◽  
Geological History ◽  
History Of ◽  
And Migration

The distributions of methylated naphthalenes in crude oils carry within them detailed information regarding the geological history of the oils. The effects of thermal stress, mixing, biodegradation and migration contamination all leave recognisable imprints, which can be deconvoluted. An extended suite of crude oils from several locations in Australia was analysed for their methylated naphthalene content. It was shown that three ratios of selected isomers, each reflecting the same underlying sedimentary reactions, are linearly related to each other when thermal stress has been the only factor controlling the distribution of methylated naphthalenes. This internal consistency allows for an assessment of maturity independent of source, age and location of the crude oil. When the relationships between the three ratios are not linear, secondary processes such as mixing, biodegradation or migration contamination have affected the crude oil. Close examination of the distribution of methylated naphthalenes can reveal the extent to which either of these processes has affected the oil.

GEOCHEMICAL CHARACTERISTICS AND SOURCE OF CHANG 8 CRUDE OIL IN THE EAST PART OF SHANBEI SLOPE, ORDOS BASIN, CHINA

2021 ◽  
pp. 1-31
Author(s):  
Zhenglu Xiao ◽  
Shijia Chen ◽  
Xiangdong Yin ◽  
Pan Wang ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Source Rock ◽  
Higher Plants ◽  
Saturated Hydrocarbon ◽  
Vitrinite Reflectance ◽  
Sedimentary Environment ◽  
Ordos Basin ◽  
Aquatic Organisms ◽  
Source Rocks ◽  
East Part

There are three sets of potential source rocks in the Yanchang Formation in the east part of the Shanbei Slope in the Ordos Basin. Based on the experimental results of total organic carbon, vitrinite reflectance, rock organic matter extraction, and saturated hydrocarbon chromatography (GC-MS), we have analyzed the geochemical and biomarker characteristics of the Chang 7, Chang 8, and Chang 9 source rocks, and the Chang 8 reservoir extracts and find that the Chang 7, Chang 8, and Chang 9 source rocks were deposited in the sedimentary environment of weak oxidation and weak reduction. Higher plants contribute more in the parent materials of the Chang 7 and Chang 9 source rocks, whereas lower aquatic organisms contribute more to the Chang 8 source rock. However, the source of the Chang 8 crude oil in the east part of Shanbei Slope does not match the chemical fingerprint of the Chang 8 source rock. To address this problem, we examined samples taken from the Zhidan oilfield, where our results show that the Chang 7, Chang 8, and Chang 9 source rocks all have hydrocarbon-supplying capacity. The relative abundance of regular steranes (C27, C28, C29) and hopane (17α(H), 21β(H)-hopane, 17β(H)-rearranged hopane, 18α(H)-22,29,30-trinorhopane) provides a means to assign the crude oil components to a given. Further analysis of the biomarkers of the three source rocks and those of the Chang 8 crude oil indicate that crude oil in the Chang 8 reservoir was not generated in situ; rather, it was supplied by the underlying Chang 9 source rock.

Prediction of °API Values of Crude Oils by Use of Saturates/Aromatics/Resins/Asphaltenes Analysis: Computational-Intelligence-Based Models

SPE Journal ◽  
2016 ◽  
Vol 22 (03) ◽  
pp. 817-853 ◽  
Author(s):  
Purva Goel ◽  
Kumar Saurabh ◽  
Veena Patil-Shinde ◽  
Sanjeev S. Tambe
Keyword(s):  
Crude Oil ◽  
Linear Model ◽  
Computational Intelligence ◽  
Nonlinear Models ◽  
Physicochemical Characteristic ◽  
Crude Oils ◽  
Support Vector ◽  
Value Prediction ◽  
Sara Fractions ◽  
The Individual

Summary The °API value is an important physicochemical characteristic of crude oils often used in determining their properties and quality. There exist models—predominantly linear ones—for predicting the °API magnitude from the molecular composition of a crude oil. This approach is tedious and time-consuming because it requires quantitative determination of numerous crude-oil components. Usually, the hydrocarbons present in a crude oil are grouped according to their molecular average structures into saturates, aromatics, resins, and asphaltenes (SARA) fractions. An °API-value prediction model dependent on these four fractions is relatively easier to develop, although this approach has been rarely used. A rigorous scrutiny suggests that some of the dependencies between the individual SARA fractions and the corresponding °API value could be nonlinear. Accordingly, in this study, SARA-fraction-based nonlinear models have been developed for the prediction of values using three computational-intelligence (CI) formalisms: genetic programming (GP), artificial-neural networks (ANNs), and support-vector regression (SVR). The SARA analyses and °API values of 403 crude-oil samples covering wide ranges have been used in developing these models. A comparison of the CI-based models with an existing linear model indicates that all the former class of models possess a significantly better °API-value prediction and generalization performance than those exhibited by the linear model. Also, the SVR-based model has been found to be the most accurate °API-value predictor. Because of their better prediction accuracy, CI-based models can be gainfully used to predict °API values of crude oils.

scholarly journals Special Distribution of Crude Oil in the Lucaogou Formation in Jimusaer Sag and Genetic Analysis of Its Physical Difference

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ming Wang ◽  
Shiju Liu ◽  
Ji Li ◽  
Gang Gao ◽  
Julei Mi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Crude Oil ◽  
Source Rocks ◽  
Crude Oils ◽  
Sweet Spot ◽  
Material Source ◽  
The Poor ◽  
Lucaogou Formation ◽  
The Difference ◽  
Sweet Spots

The shale oil of the Lucaogou Formation in the Jimusaer Sag of the Junggar Basin was divided into two sweet spots for exploration and development. Crude oil in the upper and lower sweet spots comes from the upper and lower source rocks. After years of exploration, it has been found that the crude oil in the lower sweet spot has worse physical properties than that of the upper sweet spot. In this study, through the physical and geochemical analysis of crude oil in the upper and lower sweet spots, combined with the organic petrological observation of the upper and lower source rocks, the cause of the poor physical properties of the crude oil in the lower sweet spot has been identified. n-Alkanes in the saturated hydrocarbons of crude oil in the upper and lower sweet were complete while odd-to-even predominance was evident, indicating that the poor physical properties of the crude oil are unrelated to biodegradation. In addition, the correlation between the biogenic parameters and the physical properties of crude oil was analyzed, finding that the difference in crude oil is mainly related to the composition of biogenic precursors of upper and lower source rocks. Combined with organic petrological observation, the lower source rock was found to be rich in telalginite (green algae), which is therefore the primary reason for the difference in physical properties. In comparing results from the characteristics of crude oil biomarkers from both the upper and lower sweet spots, crude oils in the upper sweet spot are similar to each other, indicating that the enrichment of crude oil has experienced a certain migration. In contrast, the differences in biomarkers between the crude oils of the lower sweet spot were relatively large and changed regularly with depth, suggesting the self-generated and self-stored characteristics of crude oil enrichment. At the same time, it was found that the crude oil in the lower sweet spot is also affected by the maturity of adjacent source rocks under the condition of a consistent parent material source. Overall, it was determined that the lower the maturity of source rocks, the poorer the physical property of the crude oil produced.

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