Oil–source rock correlation for tight oil in tuffaceous reservoirs in the Permian Tiaohu Formation, Santanghu Basin, northwest China

2015 ◽  
Vol 52 (11) ◽  
pp. 1014-1026 ◽  
Author(s):  
Jian Ma ◽  
Zhilong Huang ◽  
Xiaoyu Gao ◽  
Changchao Chen
Keyword(s):  
Organic Matter ◽  
Crude Oil ◽  
Source Rock ◽  
Stable Carbon Isotope ◽  
Northwest China ◽  
Source Rocks ◽  
Tight Oil ◽  
Stable Carbon ◽  
Lucaogou Formation ◽  
Oil Source

Tight oil in the Permian Tiaohu Formation in the Santanghu Basin, northwest China, has a peculiar property such that the reservoir is sedimentary organic matter-bearing tuff characterized by high porosity (10%–25%) and very low permeability, mainly in the range of 0.01–0.50 mD. Biomarker and stable carbon isotope compositions of selected crude oils and source-rock extracts were analyzed to determine the source rock of the tight oil. Source rocks in the Lucaogou Formation consist of various rock types dominated by mudstones containing organic matter with intense yellow–green fluorescence. Mudstones in the Lucaogou Formation have total organic carbon (TOC) values mainly in the range of 1.0–8.0 wt%, hydrocarbon generation potential (S1 + S2) mostly >6 mg/g, and chloroform extractable bitumen “A” generally >0.1%. The maceral composition is predominantly fluorescing amorphinite. The hydrogen index (HI) varies from 300 to 900 mg HC/g TOC, indicating dominant Type I and Type II kerogen. Compared with the mudstones and tuffs in the Tiaohu Formation, the mudstones in the Lucaogou Formation are the best source rocks. The biomarker characteristics of mudstone extracts in the Lucaogou Formation differ from those in the Tiaohu Formation, based on the gammacerane index, β-carotane content, and the relative contents of C27, C28, and C29 regular steranes. Crude oil samples in the tuff show low pristane/phytane (Pr/Ph) ratios, high gammacerane indices, high β-carotane, and a dominance of the C29 regular sterane followed by C28 and C27 steranes, as well as depleted stable carbon isotope compositions. Oil–source correlation with biomarkers and δ13C values shows that the crude oil in the tuffs mainly originates from underlying source rocks in the Lucaogou Formation. The sedimentary organic matter in the tuffs also makes a small contribution to the tuffaceous reservoir. Therefore, the tuffaceous tight reservoir in the Tiaohu Formation is unusual in that the oil is not indigenous; rather, it migrates a long distance to accumulate in the upper reservoir.

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.

EVIDENCE FOR A NEW OIL FAMILY IN THE NANCAR TROUGH AREA, TIMOR SEA

2002 ◽  
Vol 42 (1) ◽  
pp. 387 ◽  
Author(s):  
S.C. George ◽  
H. Volk ◽  
T.E. Ruble ◽  
M.P. Brincat
Keyword(s):  
Organic Matter ◽  
Fluid Inclusion ◽  
Source Rock ◽  
Bacterial Activity ◽  
Source Rocks ◽  
Drilling Mud ◽  
Terrestrial Organic Matter ◽  
High Contribution ◽  
Timor Sea ◽  
Oil Source

Geochemical evidence is presented for a previously unrecognised oil generative source rock in the Nancar Trough area. This source rock supplements the middle to late Jurassic source rocks, which have previously been shown to have generated most of the oils in the northern Bonaparte Basin and the Vulcan Sub-basin. Fluids with a strong contribution from this new source rock, defined here as the Nancar oil family, have an unusually high abundance of mid-chain substituted monomethylalkanes. In comparison, oils from the Vulcan Sub-basin contain mostly terminally substituted monomethylalkanes and the overall abundance is much lower. Oils from the Laminaria High and some from the northern Vulcan Sub-Basin show intermediate characteristics and may be co-sourced. Evidence from the analysis of fluid inclusion oils was important in establishing the presence of the new oil family because interference from drilling mud contaminants could be excluded. The detailed geochemistry of Ludmilla–1 fluid inclusion oil suggests the source rock for the Nancar oil family was deposited in a marine environment under sub-oxic conditions with limited sulphur content, a low contribution of terrestrial organic matter and a high contribution of organic matter from bacterial activity. Since monomethylalkanes are typical biomarkers of cyanobacteria, the source rock that gave rise to the new oil family may be rich in cyanobacterial organic matter. Further studies on sediment extracts are needed to establish an explicit oil-source rock correlation and to identify the stratigraphic location/palaeo-environment of the source rock. Such information will be valuable in determining the prospectivity of the large and relatively unexplored province draining the Nancar Trough kitchen.

Oil–oil and oil-source rock correlations in the Alpine Foreland Basin of Austria: Insights from biomarker and stable carbon isotope studies

2011 ◽  
Vol 28 (6) ◽  
pp. 1171-1186 ◽  
Author(s):  
Reinhard Gratzer ◽  
Achim Bechtel ◽  
Reinhard F. Sachsenhofer ◽  
Hans-Gert Linzer ◽  
Doris Reischenbacher ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Source Rock ◽  
Stable Carbon Isotope ◽  
Foreland Basin ◽  
Stable Carbon ◽  
Alpine Foreland ◽  
Alpine Foreland Basin ◽  
Isotope Studies ◽  
Oil Source

GEOCHEMICAL AND COMPOUND SPECIFIC CARBON ISOTOPIC CHARACTERISATION OF FLUID INCLUSION OILS FROM THE OFFSHORE PERTH BASIN,WESTERN AUSTRALIA: IMPLICATIONS FOR RECOGNISING EFFECTIVE OIL SOURCE ROCKS

2004 ◽  
Vol 44 (1) ◽  
pp. 223 ◽  
Author(s):  
H. Volk ◽  
S.C. George ◽  
C.J. Boreham ◽  
R.H. Kempton
Keyword(s):  
Organic Matter ◽  
Fluid Inclusion ◽  
Source Rock ◽  
Early Cretaceous ◽  
Source Rocks ◽  
Molecular Evidence ◽  
Terrestrial Organic Matter ◽  
Carbon Isotopic ◽  
Oil Source ◽  
Coal Measures

The molecular composition of fluid inclusion (FI) oils from Leander Reef–1, Houtman–1 and Gage Roads–2 provide evidence of the origin of palaeo-oil accumulations in the offshore Perth Basin. These data are complemented by compound specific isotope (CSI) profiles of n-alkanes for the Leander Reef–1 and Houtman–1 samples, which were acquired on purified n-alkane fractions gained by micro-fractionation of lean FI oil samples, showing the technical feasibility of this technique. The Leander Reef–1 FI oil from the top Carynginia Formation shares many biomarker similarities with oils from the Dongara and Yardarino oilfields, which have been correlated with the Early Triassic Kockatea Shale. The heavier isotopic values for the C15-C25 n-alkanes in the Leander Reef–1 FI oil indicate, however, that it is a mixture, and suggest that the main part of this oil (~90%) was sourced from the more terrestrial and isotopically heavier Early Permian Carynginia Formation or Irwin River Coal Measures. This insight would have been precluded when looking at molecular evidence alone. The Houtman–1 FI oil from the top Cattamarra Coal Measures (Middle Jurassic) was sourced from a clay-rich, low sulphur source rock with a significant input of terrestrial organic matter, deposited under oxic to sub-oxic conditions. Biomarkers suggest sourcing from a more prokaryotic-dominated facies than for the other FI oils, possibly a saline lagoon. The Houtman–1 FI oil δ13C CSI n-alkane data are similar to those acquired on the Walyering–2 oil. Possible lacustrine sources may exist in the Early Jurassic Eneabba Formation and are present in the Late Jurassic Yarragadee Formation. The low maturity Gage Roads–2 FI oil from the Carnac Formation (Early Cretaceous) was derived from a strongly terrestrial, non-marine source rock containing a high proportion of Araucariacean-type conifer organic matter. It has some geochemical differences to the presently reservoired oil in Gage Roads–1, and was probably sourced from the Early Cretaceous Parmelia Formation.

Sign in / Sign up

Export Citation Format

Share Document