3D-Basin Modelling of the Lishui Sag: Research of Hydrocarbon Potential, Petroleum Generation and Migration

The Lishui Sag is located in the southeastern part of the Taibei Depression, in the East China Sea basin, where the sag is the major hydrocarbon accumulation zone. A three dimensional modelling approach was used to estimate the mass of petroleum generation and accumulated during the evolution of the basin. Calibration of the model, based on measured maturity (vitrinite reflectance) and borehole temperatures, took into consideration two main periods of erosion events: a late Cretaceous to early Paleocene event, and an Oligocene erosion event. The maturation histories of the main source rock formations were reconstructed and show that the peak maturities have been reached in the west central part of the basin. Our study included source rock analysis, measurement of fluid inclusion homogenization temperatures, and basin history modelling to define the source rock properties, the thermal evolution and hydrocarbon generation history, and possible hydrocarbon accumulation processes in the Lishui Sag. The study found that the main hydrocarbon source for the Lishui Sag are argillaceous source rocks in the Yueguifeng Formation. The hydrocarbon generation period lasted from 58 Ma to 32 Ma. The first period of hydrocarbon accumulation lasted from 51.8 Ma to 32 Ma, and the second period lasted from 23 Ma to the present. The accumulation zones mainly located in the structural high and lithologic-fault screened reservoir filling with the hydrocarbon migrated from the deep sag in the south west direction.

Download Full-text

Effects of igneous intrusions on source rock in the early diagenetic stage: A case study on Beipiao Formation in Jinyang Basin, Northeast China

Open Geosciences ◽

10.1515/geo-2020-0150 ◽

2020 ◽

Vol 12 (1) ◽

pp. 990-1002

Author(s):

Shouliang Sun ◽

Tao Zhang ◽

Yongfei Li ◽

Shuwang Chen ◽

Qiushi Sun

Keyword(s):

Source Rock ◽

Oil And Gas ◽

Thermal Evolution ◽

Vitrinite Reflectance ◽

Scientific Basis ◽

Source Rocks ◽

Temperature History ◽

Hydrocarbon Generation ◽

Intrusive Body ◽

Geochemical Parameters

AbstractMesozoic intrusive bodies play an important role in the temperature history and hydrocarbon maturation of the Jinyang Basin in northeastern China. The Beipiao Formation, which is the main source rock in Jinyang Basin, was intruded by numerous igneous bodies and dykes in many areas. The effects of igneous intrusive bodies on thermal evolution and hydrocarbon generation and migration in the Beipiao Formation were investigated. A series of samples from the outcrop near the intrusive body were analyzed for vitrinite reflectance (R0%) and other organic geochemical parameters to evaluate the lateral extension of the thermal aureole. The R0 values of the samples increase from a background value of ∼0.9% at a distance above 200 m from the intrusive body to more than 2.0% at the vicinity of the contact zone. The width of the altered zone is equal to the thickness of the intrusive body outcropped in the field. Organic geochemical proxies also indicate the intrusive body plays a positive and beneficial role in the formation of regional oil and gas resources. Due to the influence of the anomalous heat from the intrusive body, the hydrocarbon conversion rate of the source rocks of the Beipiao Formation was significantly improved. The accumulation properties and the storage capacity of the shales also greatly improved due to the intrusive body as indicated by the free hydrocarbon migration in the shales. This new understanding not only provides a reliable scientific basis for the accurate assessment of oil and gas genesis and resources in the Jinyang Basin but also provides guidance and reference for oil and gas exploration in the similar type of basin.

Download Full-text

A HYDROCARBON GENERATION MODEL FOR THE COOPER AND EROMANGA BASINS

The APPEA Journal ◽

10.1071/aj02023 ◽

2003 ◽

Vol 43 (1) ◽

pp. 433 ◽

Cited By ~ 7

Author(s):

I. Deighton ◽

J.J. Draper ◽

A.J. Hill ◽

C.J. Boreham

Keyword(s):

Source Rock ◽

Source Rocks ◽

Generation Model ◽

Hydrocarbon Generation ◽

Control Points ◽

Seismic Structure ◽

Dynamic Topography ◽

Late Tertiary ◽

Petroleum Generation ◽

Eromanga Basin

The aim of the National Geoscience Mapping Accord Cooper-Eromanga Basins Project was to develop a quantitative petroleum generation model for the Cooper and Eromanga Basins by delineating basin fill, thermal history and generation potential of key stratigraphic intervals. Bio- and lithostratigraphic frameworks were developed that were uniform across state boundaries. Similarly cross-border seismic horizon maps were prepared for the C horizon (top Cadna-owie Formation), P horizon (top Patchawarra Formation) and Z horizon (base Eromanga/Cooper Basins). Derivative maps, such as isopach maps, were prepared from the seismic horizon maps.Burial geohistory plots were constructed using standard decompaction techniques, a fluctuating sea level and palaeo-waterdepths. Using terrestrial compaction and a palaeo-elevation for the Winton Formation, tectonic subsidence during the Winton Formation deposition and erosion is the same as the background Eromanga Basin trend—this differs significantly from previous studies which attributed apparently rapid deposition of the Winton Formation to basement subsidence. A dynamic topography model explains many of the features of basin history during the Cretaceous. Palaeo-temperature modelling showed a high heatflow peak from 90–85 Ma. The origin of this peak is unknown. There is also a peak over the last two–five million years.Expulsion maps were prepared for the source rock units studied. In preparing these maps the following assumptions were made:expulsion is proportional to maturity and source rock richness;maturity is proportional to peak temperature; andpeak temperature is proportional to palaeo-heatflow and palaeo-burial.The geohistory modelling involved 111 control points. The major expulsion is in the mid-Cretaceous with minor amounts in the late Tertiary. Maturity maps were prepared by draping seismic structure over maturity values at control points. Draping of maturity maps over expulsion values at the control points was used to produce expulsion maps. Hydrocarbon generation was calculated using a composite kerogen kinetic model. Volumes generated are theoretically large, up to 120 BBL m2 of kitchen area at Tirrawarra North. Maps were prepared for the Patchawarra and Toolachee Formations in the Cooper Basin and the Birkhead and Poolowanna Formations in the Eromanga Basins. In addition, maps were prepared for Tertiary expulsion. The Permian units represent the dominant source as Jurassic source rocks have only generated in the deepest parts of the Eromanga Basin.

Download Full-text

GEOCHEMICAL TOOLS FOR EVALUATING PETROLEUM GENERATION IN MIDDLE PROTEROZOIC SEDIMENTS OF THE McARTHUR BASIN, NORTHERN TERRITORY, AUSTRALIA

The APPEA Journal ◽

10.1071/aj93051 ◽

1994 ◽

Vol 34 (1) ◽

pp. 692 ◽

Cited By ~ 4

Author(s):

Roger E. Summons ◽

Dennis Taylor ◽

Christopher J. Boreham

Keyword(s):

Vitrinite Reflectance ◽

Land Plant ◽

Source Rocks ◽

Hydrocarbon Generation ◽

Strongly Correlated ◽

Petroleum Potential ◽

Petroleum Generation ◽

Early Palaeozoic ◽

Geochemical Analyses ◽

Rock Eval

Maturation parameters based on aromatic hydrocarbons, and particularly the methyl-phenanthrene index (MPI-1), are powerful indicators which can be used to define the oil window in Proterozoic and Early Palaeozoic petroleum source rocks and to compare maturities and detect migration in very old oils . The conventional vitrinite reflectance yardstick for maturity is not readily translated to these ancient sediments because they predate the evolution of the land plant precursors to vitrinite. While whole-rock geochemical tools such as Rock-Eval and TOC are useful for evaluation of petroleum potential, they can be imprecise when applied to maturity assessments.In this study, we carried out a range of detailed geochemical analyses on McArthur Basin boreholes penetrating the Roper Group source rocks. We determined the depth profiles for hydrocarbon generation based on Rock-Eval analysis of whole-rock, solvent-extracted rock, kerogen elemental H/C ratio and pyrolysis GC. Although we found that Hydrogen Index (HI) and the Tmax parameter were strongly correlated with other maturation indicators, they were not sufficiently sensitive nor were they universally applicable. Maturation measurements based on saturated biomarkers were not useful either because of the low abundance of these compounds in most Roper Group bitumens and oils.

Download Full-text

Hydrocarbon Generation Indication from Source Rock to Reservoir Rock: Case Studies of Anambra and Abakaliki Basins South-Eastern Nigeria

10.2118/afrc-2560967-ms ◽

2016 ◽

Author(s):

Samuel Salufu ◽

Rita Onolemhemhen ◽

Sunday Isehunwa

Keyword(s):

Case Studies ◽

Source Rock ◽

Oil And Gas ◽

Vitrinite Reflectance ◽

Source Rocks ◽

Reservoir Rock ◽

Hydrocarbon Generation ◽

Geochemical Analysis ◽

Anambra Basin ◽

Oil Generation

ABSTRACT This paper sought to use information from outcrop sections to characterize the source and reservoir rocks in a basin in order to give indication(s) for hydrocarbon generation potential in a basin in minimizing uncertainty and risk that are allied with exploration and field development of oil and gas, using subsurface data from well logs, well sections, seismic and core. The methods of study includes detailed geological, stratigraphical, geochemical, structural,, petro-graphical, and sedimentological studies of rock units from outcrop sections within two basins; Anambra Basin and Abakaliki Basin were used as case studies. Thirty eight samples of shale were collected from these Basins; geochemical analysis (rockeval) was performed on the samples to determine the total organic content (TOC) and to assess the oil generating window. The results were analyzed using Rock wares, Origin, and Surfer software in order to properly characterize the potential source rock(s) and reservoir rock(s) in the basins, and factor(s) that can favour hydrocarbon traps. The results of the geological, stratigraphical, sedimentological, geochemical, and structural, were used to developed a new model for hydrocarbon generation in the Basins. The result of the geochemical analysis of shale samples from the Anambra Basin shows that the TOC values are ≥ 1wt%, Tmax ≥ 431°C, Vitrinite reflectance values are ≥ 0.6%, and S1+S2 values are > 2.5mg/g for Mamu Formation while shale samples from other formations within Anambra Basin fall out of these ranges. The shale unit in the Mamu Formation is the major source rock for oil generation in the Anambra Basin while others have potential for gas generation with very little oil generation. The shale samples from Abakaliki Basin shows that S1+S2 values range from< 1 – 20mg/g, TOC values range from 0.31-4.55wt%, vitrinite reflectance ranges from 0.41-1.24% and Tmax ranges from423°C – 466°C. This result also shows that there is no source rock for oil generation in Abakaliki Basin; it is either gas or graphite. This observation indicates that all the source rocks within Abakaliki Basin have exceeded petroleum generating stage due to high geothermal heat resulting from deep depth or the shale units have not attained catagenesis stage as a result of S1+S2 values lesser than 2.5mg/g despite TOC values of ≥ 0.5wt% and vitrinite reflectance values of ≥ 0.6%. The novelty of this study is that the study has been able to show that here there is much more oil than the previous authors claimed, and the distribution of this oil and gas in the basins is controlled by two major factors; the pattern of distribution of the materials of the source rock prior to subsidence and during the subsidence period in the basin, and the pattern and the rate of tectonic activities, and heat flow in the basin. If these factors are known, it would help to reduce the uncertainties associated with exploration for oil and gas in the two basins.

Download Full-text

Evaluation of the quality, thermal maturity and distribution of potential source rocks in the Danish part of the Norwegian–Danish Basin

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/geusb.v16.4989 ◽

2008 ◽

Vol 16 ◽

pp. 1-66 ◽

Cited By ~ 5

Author(s):

Henrik I. Petersen ◽

Lars H. Nielsen ◽

Jørgen A. Bojesen-Koefoed ◽

Anders Mathiesen ◽

Lars Kristensen ◽

...

Keyword(s):

Source Rock ◽

Early Cretaceous ◽

Middle Jurassic ◽

Upper Cretaceous ◽

Vitrinite Reflectance ◽

Lower Jurassic ◽

Source Rocks ◽

Thermal Maturity ◽

Potential Source ◽

Petroleum Generation

The quality, thermal maturity and distribution of potential source rocks within the Palaeozoic–Mesozoic succession of the Danish part of the Norwegian-Danish Basin have been evaluated on the basis of screening data from over 4000 samples from the pre-Upper Cretaceous succession in 33 wells. The Lower Palaeozoic in the basin is overmature and the Upper Cretaceous – Cenozoic strata have no petroleum generation potential, but the Toarcian marine shales of the Lower Jurassic Fjerritslev Formation (F-III, F-IV members) and the uppermost Jurassic – lowermost Cretaceous shales of the Frederikshavn Formation may qualify as potential source rocks in parts of the basin. Neither of these potential source rocks has a basinwide distribution; the present occurrence of the Lower Jurassic shales was primarily determined by regional early Middle Jurassic uplift and erosion. The generation potential of these source rocks is highly variable. The F-III and F-IV members show significant lateral changes in generation capacity, the best-developed source rocks occurring in the basin centre. The combined F-III and F-IV members in the Haldager-1, Kvols-1 and Rønde-1 wells contain 'net source-rock' thicknesses (cumulative thickness of intervals with Hydrogen Index (HI)> 200 mg HC/g TOC) of 40 m, 83 m, and 92 m, respectively, displaying average HI values of 294, 369 and 404 mg HC/g TOC. The Mors-1 well contains 123 m of 'net source rock' with an average HI of 221 mg HC/g TOC. Parts of the Frederikshavn Formation possess a petroleum generation potential in the Hyllebjerg-1, Skagen-2, Voldum-1 and Terne-1 wells, the latter well containing a c. 160 m thick highly oil-prone interval with an average HI of 478 mg HC/g TOC and maximum HI values> 500 mg HC/g TOC.The source-rock evaluation suggests that a Mesozoic petroleum system is the most likely in the study area. Two primary plays are possible: (1) the Upper Triassic – lowermost Jurassic Gassum play, and (2) the Middle Jurassic Haldager Sand play. Potential trap structures are widely distributed in the basin, most commonly associated with the flanks of salt diapirs. The plays rely on charge from the Lower Jurassic (Toarcian) or uppermost Jurassic – lowermost Cretaceous shales. Both plays have been tested with negative results, however, and failure is typically attributed to insufficient maturation (burial depth) of the source rocks. This maturation question has been investigated by analysis of vitrinite reflectance data from the study area, corrected for post-Early Cretaceous uplift. A likely depth to the top of the oil window (vitrinite reflectance = 0.6%Ro) is c. 3050–3100 m based on regional coalification curves. The Frederikshavn Formation had not been buried to this depth prior to post-Early Cretaceous exhumation, and the potential source rocks of the formation are thermally immature in terms of hydrocarbon generation. The potential source rocks of the Fjerritslev Formation are generally immature to very early mature. Mature source rocks in the Danish part of the Norwegian–Danish Basin are thus dependent on local, deeper burial to reach the required thermal maturity for oil generation. Such potential kitchen areas with mature Fjerritslev Formation source rocks may occur in the central part of the study area (central–northern Jylland), and a few places offshore. These inferred petroleum kitchens are areally restricted, mainly associated with salt structures and local grabens (such as the Fjerritslev Trough and the Himmerland Graben).

Download Full-text

Hydrocarbon accumulation and formation of composite reservoirs in KL16-1 of Laizhou Bay Sag, Bohai Sea, China

Energy Exploration & Exploitation ◽

10.1177/0144598718760899 ◽

2018 ◽

Vol 36 (6) ◽

pp. 1395-1423 ◽

Cited By ~ 4

Author(s):

Yunlong Xu ◽

Xiaoping Luo ◽

Ajuan Wei ◽

Mingcai Hou ◽

Haoming Wu ◽

...

Keyword(s):

Source Rock ◽

Bohai Sea ◽

Primary Source ◽

Source Rocks ◽

Laizhou Bay ◽

Secondary Source ◽

Hydrocarbon Generation ◽

Hydrocarbon Accumulation ◽

Accumulation Process ◽

Rock Layer

The Laizhou Bay Sag, one of the oil-bearing sags with large exploration potential in the South Bohai Sea of China, contains two sets of high-quality hydrocarbon source rocks, i.e. Member 3 and Member 4 of Shahejie Fm (E2s3 and E2s4). As an important hydrocarbon accumulation zone in the sag, the KL16-1 low bulge is found to have oil reservoirs in the Neogene Guantao Fm (N1g), the Paleogene Dongying Fm (E3d), the Paleogene Shahejie Fm (E2s), and the Mesozoic buried hill formation. It is characterized by distinct features of composite reservoirs. Nonetheless, its hydrocarbon accumulation process and mechanism are unknown yet. In this paper, the hydrocarbon generation modelling of source rocks, combined with the characteristics of oil-source rock biomarker compounds and fluid inclusions, is used to restore the hydrocarbon accumulation process in the KL16-1 low bulge. Crude oil in all three KL16-1 plays is characterized by low Pr/Ph, low gammacerane, high 4-methyl sterane and high dinosterane. In other words, it is oil of low maturity to maturity. As the biomarker index of the oil is very similar to that of the E2s3 source rocks, it is thought that E2s3 is the primary source rock layer, while E2s4 is the secondary source rock layer. In addition, episodic oil and gas charging happened in two phases under high pressure in the late period (from 5.0 Ma till now).

Download Full-text

Source rock characteristics and hydrocarbon generation potential in Brunei-Muara district, Brunei Darussalam: a comparative case study from selected Miocene-Quaternary formations

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01142-0 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1679-1703

Author(s):

Liyana Nadiah Osli ◽

Mohamed Ragab Shalaby ◽

Md. Aminul Islam

Keyword(s):

Organic Matter ◽

Source Rock ◽

Vegetation Index ◽

Oil And Gas ◽

Vitrinite Reflectance ◽

Rock Properties ◽

Comparative Case Study ◽

Hydrocarbon Generation ◽

Brunei Darussalam ◽

Potential Source Rock

AbstractA comparative analysis on source rock properties has been carried out on the Miocene-Pliocene formations as well as the Quaternary terrace deposits using Rock–Eval pyrolysis results and organic petrography as well as some biomarkers results. Samples were obtained from outcrops of the Quaternary terrace deposits, Pliocene-aged Liang Formation together with the Miocene Miri and Setap Shale formations in Brunei-Muara district, with sample lithologies ranging from coal, coaly shale, shale and lignitic sand. High total organic carbon (TOC) and S2 values ranging from 41.8 to 62.4% and 7.40 mg HC/g rock to 122 mg HC/g rock, respectively, are identified in coals of the terrace deposit, Liang and Miri formations, making these as the best potential source rock due to the “good to excellent” generating potential. Meanwhile, a “fair to poor” potential is exhibited for the coaly shale, shale and lignitic sand samples as a result of their low TOC, HI and S2 values. The organic matter is composed of kerogen type III (gas prone) and type II-III (mixed oil and gas prone). Organic matter in all studied formations originate from a terrestrial-source, as proven by the abundance of huminite. Organic petrographical and biomarkers studies suggest that the coals and lignitic sand samples were deposited in a mangrove-type mire in a lower delta setting, under oxic and limnic to limnotelmatic conditions, except sample DD2-1, which is deposited in a less water-saturated environment. The samples display the presence of bi-modal and normal distribution of n-alkanes. For all of the samples, the dominating plant types in the palaeomire are of soft, herbaceous plants and this is supported by the low vegetation index and moderate Paq values. All the studied samples are thermally immature to early mature, as exhibited by the Tmax values that range from 300 to 437 °C and vitrinite reflectance readings of 0.22% to 0.46%.

Download Full-text

Evaluation of Hydrocarbon Generation Using Structural and Thermal Modeling in the Thrust Belt of Kuqa Foreland Basin, NW China

Geofluids ◽

10.1155/2020/8894030 ◽

2020 ◽

Vol 2020 ◽

pp. 1-18

Author(s):

Chengfu Lyu ◽

Xixin Wang ◽

Xuesong Lu ◽

Qianshan Zhou ◽

Ying Zhang ◽

...

Keyword(s):

Source Rock ◽

Oil And Gas ◽

Thermal Evolution ◽

Foreland Basin ◽

Source Rocks ◽

Mature Stage ◽

Hydrocarbon Generation ◽

Thrust Belt ◽

Salt Layer ◽

Kuqa Foreland Basin

The Kuqa Basin is a typical foreland basin in northwest China, characterized by compressive foreland fold-and-thrust belts and a regionally distributed huge salt layer. A large number of overthrust faults, fault-related folds, and salt-related structures are formed on the thrust belt due to strong compression and structural deformation, causing difficulty in simulation of the basin. In this study, modeling of the thermal history of the complicated compressional structural profiles in the Kuqa foreland basin was successfully conducted based on the advanced “Block” function introduced by the IES PetroMod software and the latest geological interpretation results. In contrast to methods used in previous studies, our method comprehensively evaluates the influence of overthrusting, a large thick salt layer with low thermal conductivity, fast deposition, or denudation on the thermal evolution history. The results demonstrate that the hydrocarbon generation center of the Kuqa foreland basin is in the deep layers of the Kelasu thrust belt and not in the Baicheng Sag center, which is buried the deepest. A surprising result was drawn about the center of hydrocarbon generation in the Kuqa foreland basin, which, although not the deepest in Baicheng Sag, is the deepest part of the Kelasu thrust Belt. In terms of the maturity of the source rock, there are obvious temporal and spatial differences between the different structural belts in the Kuqa foreland basin, such as the early maturation of source rocks and the curbing of uplift and hydrocarbon generation in the piedmont zone. In the Kelasu thrust belt, the source rock made an early development into the low mature-mature stage and subsequently rapidly grew into a high-over mature stage. In contrast, the source rock was immature at an early stage and subsequently grew into a low mature-mature stage in the Baicheng Sag–South slope belt. The time sequence of the thermal evolution of source rocks and structural trap formation and their matching determines the different accumulation processes and oil and gas compositions in the different structural belts of the Kuqa foreland basin. The matching of the multistage tectonic activity and hydrocarbon generation determines the characteristics of the multistage oil and gas accumulation, with the late accumulation being dominant. The effective stacking of the gas generation center, subsalt structural traps, reservoir facies of fine quality, and huge, thick salt caprocks creates uniquely favorable geological conditions for gas enrichment in the Kelasu foreland thrust belt.

Download Full-text

Oil to Source Rock Correlation Using Biomarker Data Through Pattern Matching and Fingerprinting Analysis in “Kitkat” Field, Jabung Block, South Sumatra Basin

Proc. Indon. Petrol. Assoc., Digital Technical Conference, 2020 ◽

10.29118/ipa20-sg-251 ◽

2020 ◽

Author(s):

S., R. Muthasyabiha

Keyword(s):

Pattern Matching ◽

Source Rock ◽

Vitrinite Reflectance ◽

Hydrocarbon Exploration ◽

Source Rocks ◽

Maturity Level ◽

Fingerprinting Analysis ◽

Kerogen Type ◽

Oil Characteristics ◽

Biomarker Data

Geochemical analysis is necessary to enable the optimization of hydrocarbon exploration. In this research, it is used to determine the oil characteristics and the type of source rock candidates that produces hydrocarbon in the “KITKAT” Field and also to understand the quality, quantity and maturity of proven source rocks. The evaluation of source rock was obtained from Rock-Eval Pyrolysis (REP) to determine the hydrocarbon type and analysis of the value of Total Organic Carbon (TOC) was performed to know the quantity of its organic content. Analysis of Tmax value and Vitrinite Reflectance (Ro) was also performed to know the maturity level of the source rock samples. Then the oil characteristics such as the depositional environment of source rock candidate and where the oil sample develops were obtained from pattern matching and fingerprinting analysis of Biomarker data GC/GCMS. Moreover, these data are used to know the correlation of oil to source rock. The result of source rock evaluation shows that the Talangakar Formation (TAF) has all these parameters as a source rock. Organic material from Upper Talangakar Formation (UTAF) comes from kerogen type II/III that is capable of producing oil and gas (Espitalie, 1985) and Lower Talangakar Formation (LTAF) comes from kerogen type III that is capable of producing gas. All intervals of TAF have a quantity value from very good–excellent considerable from the amount of TOC > 1% (Peters and Cassa, 1994). Source rock maturity level (Ro > 0.6) in UTAF is mature–late mature and LTAF is late mature–over mature (Peters and Cassa, 1994). Source rock from UTAF has deposited in the transition environment, and source rock from LTAF has deposited in the terrestrial environment. The correlation of oil to source rock shows that oil sample is positively correlated with the UTAF.

Download Full-text

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

Petroleum Science ◽

10.1007/s12182-021-00554-1 ◽

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.

Download Full-text