Expression of the Colorado Mineral Belt in Upper Cretaceous Niobrara Formation Source Rock Maturity Data from the Denver Basin

2018 ◽  
Vol 55 (1) ◽  
pp. 19-52
Author(s):  
David Thul ◽  
Stephen Sonnenberg
Keyword(s):  
Source Rock ◽  
Oil And Gas ◽  
Thermal Anomaly ◽  
Source Rocks ◽  
Niobrara Formation ◽  
Denver Basin ◽  
Bottom Hole ◽  
Mineral Belt ◽  
Colorado Mineral ◽  
Hydrocarbon Expulsion

New source rock maturity data along the Colorado Mineral Belt trend in the Denver Basin reveal that source rocks in the deepest portion of the basin range from the onset of oil generation to wet gas maturity across a distance of less than 30 miles along present day structure. Additionally, sampled rock core and cuttings along a northeast-southwest transect reveal that the Niobrara Formation is within the oil maturity window all the way to the Nebraska-Colorado border. The correlation of these analyses to an identified thermal anomaly demonstrate that maturity along these trends is affected by a historical increase in heat flow that can still be seen in the present-day bottom-hole temperatures. The identified maturity anomaly has significant implications for Niobrara prospectivity within the basin. Crossplotting, mapping, and numerical modeling show the onset of hydrocarbon maturity in the Niobrara is represented by 432 °C Tmax and that hydrocarbon expulsion occurs between 438 °C and 443 °C Tmax. In the Niobrara Formation of the Denver Basin there is a strong correlation between oil and gas shows, elevated bottom-hole temperatures (and thermal gradients), and geochemical maturity parameters. Through mapping of maturity and free hydrocarbon anomalies, more than 80% of the present day production can be predicted with source rock mapping.

scholarly journals GEOCHEMICAL AND GEOSTATISTICAL ASSESSMENT OF CRETACEOUS COALS AND SHALES IN SOME NIGERAIN SEDIMENTARY BASINS FOR THEIR HYDROCARBON PRONESS AND MATURITY LEVELS

2020 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Source Rock ◽  
Oil And Gas ◽  
Linear Regression Analysis ◽  
Sedimentary Basins ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Good Source ◽  
Type Iii ◽  
Limit Value ◽  
The Impact

The Rock–Eval pyrolysis and LECO analysis for 9 shale and 12 coal samples, as well as, geostatistical analysis have been used to investigate source rock characteristics, correlation between the assessed parameters (QI, BI, S1, S2, S3, HI, S1 + S2, OI, PI, TOC) and the impact of changes in the Tmax on the assessed parameters in the Cretaceous Sokoto, Anambra Basins and Middle Benue Trough of northwestern, southeastern and northcentral Nigeria respectively. The geochemical results point that about 97% of the samples have TOC values greater than the minimum limit value (0.5 wt %) required to induce hydrocarbon generation from source rocks. Meanwhile, the Dukamaje and Taloka shales and Lafia/Obi coal are found to be fair to good source rock for oil generation with slightly higher thermal maturation. The source rocks are generally immature through sub-mature to marginal mature with respect to the oil and gas window, while the potential source rocks from the Anambra Basin are generally sub-mature grading to mature within the oil window. The analyzed data were approached statistically to find some relations such as factors, and clusters concerning the examination of the source rocks. These factors were categorized into type of organic matter and organic richness, thermal maturity and hydrocarbon potency. In addendum, cluster analysis separated the source rocks in the study area into two groups. The source rocks characterized by HI >240 (mg/g), TOC from 58.89 to 66.43 wt %, S1 from 2.01 to 2.54 (mg/g) and S2 from 148.94 to 162.52 (mg/g) indicating good to excellent source rocks with kerogen of type II and type III and are capable of generating oil and gas. Followed by the Source rocks characterized by HI <240 (mg/g), TOC from 0.94 to 36.12 wt%, S1 from 0.14 to 0.72 (mg/g) and S2 from 0.14 to 20.38 (mg/g) indicating poor to good source rocks with kerogen of type III and are capable of generating gas. Howeverr, Pearson’s correlation coefficient and linear regression analysis shows a significant positive correlation between TOC and S1, S2 and HI and no correlation between TOC and Tmax, highly negative correlation between TOC and OI and no correlation between Tmax and HI. Keywords- Cretaceous, Geochemical, Statistical, Cluster; Factor analyses.

Geochemical Inversion - A Modern Approach to Inferring Source-Rock Identity from Characteristics of Accumulated Oil and Gas

1993 ◽  
Vol 11 (3-4) ◽  
pp. 295-328 ◽  
Author(s):  
K.K. Bissada ◽  
L.W. Elrod ◽  
C.R. Robison ◽  
L.M. Darnell ◽  
H.M. Szymczyk ◽  
...  
Keyword(s):  
Source Rock ◽  
Oil And Gas ◽  
Source Rocks ◽  
Specific Information ◽  
Modern Approach ◽  
Age Identity ◽  
Oil And Natural Gas ◽  
Architectural Constraints ◽  
Geologic Setting ◽  
Relative Migration

In recent years, petroleum geochemists have been re-focusing their efforts on developing practical means for inferring, from hydrocarbon chemistry and geologic constraints, the “provenance” of hydrocarbon accumulations, seeps or stains. This capability, referred to here as “Geochemical Inversion”, can be invaluable to the explorationist in deriving clues as to the character, age, identity, maturity and location of an accumulation's source rocks and evaluating a petroleum system's hydrocarbon supply volumetrics. Geochemical inversion is most useful where pertinent source-rock information may be absent because exploratory drilling focused strictly on structural highs and failed to penetrate the deeply buried, effective basinal source facies. Advances in chemical analysis technology over the last decade have facilitated the development of powerful geochemical methods for unravelling of complex chemistries of crude oil and natural gas at the molecular and subatomic levels to extract specific information on the hydrocarbons' source. Inferences on such factors as organic matter make-up, depositional environment, lithology, age and maturity of the source can frequently be drawn. These inferences, together with a sound analysis of the geologic and architectural constraints on the system, can supply clues as to the identity and location of the probable source sequence. This paper describes the principles underlying geochemical “inversion” and provides applications in exploration and exploitation settings. In addition, this paper demonstrates inversion of geochemical characteristics of migrated hydrocarbon fluids to specific attributes of the source. The paper also illustrates the use of systematic variations in fluid chemistry within a geologic setting to infer source location, degree of hydrocarbon mixing and relative migration distance.

NEW PETROLEUM MODELS IN THE PEDIRKA BASIN, NORTHERN TERRITORY, AUSTRALIA

2002 ◽  
Vol 42 (1) ◽  
pp. 259 ◽  
Author(s):  
G.J. Ambrose ◽  
K. Liu ◽  
I. Deighton ◽  
P.J. Eadington ◽  
C.J. Boreham
Keyword(s):  
Oil And Gas ◽  
South Australia ◽  
Sedimentary Basins ◽  
Poor Quality ◽  
Northern Territory ◽  
Early Jurassic ◽  
Source Rocks ◽  
Late Triassic ◽  
Hydrocarbon Expulsion ◽  
Migration Pathways

The northern Pedirka Basin in the Northern Territory is sparsely explored compared with its southern counterpart in South Australia. Only seven wells and 2,500 km of seismic data occur over a prospective area of 73,000 km2 which comprises three stacked sedimentary basins of Palaeozoic to Mesozoic age. In this area three petroleum systems have potential related to important source intervals in the Early Jurassic Eromanga Basin (Poolowanna Formation), the Triassic Simpson Basin (Peera Peera Formation) and Early Permian Pedirka Basin (Purni Formation). They are variably developed in three prospective depocentres, the Eringa Trough, the Madigan Trough and the northern Poolowanna Trough. Basin modelling using modern techniques indicate oil and gas expulsion responded to increasing early Late Cretaceous temperatures in part due to sediment loading (Winton Formation). Using a composite kinetic model, oil and gas expulsion from coal rich source rocks were largely coincident at this time, when source rocks entered the wet gas maturation window.The Purni Formation coals provide the richest source rocks and equate to the lower Patchawarra Formation in the Cooper Basin. Widespread well intersections indicate that glacial outwash sandstones at the base of the Purni Formation, herein referred to as the Tirrawarra Sandstone equivalent, have regional extent and are an important exploration target as well as providing a direct correlation with the prolific Patchawarra/Tirrawarra petroleum system found in the Cooper Basin.An integrated investigation into the hydrocarbon charge and migration history of Colson–1 was carried out using CSIRO Petroleum’s OMI (Oil Migration Intervals), QGF (Quantitative Grain Fluorescence) and GOI (Grains with Oil Inclusions) technologies. In the Early Jurassic Poolowanna Formation between 1984 and 2054 mRT, elevated QGF intensities, evidence of oil inclusions and abundant fluorescing material trapped in quartz grains and low displacement pressure measurements collectively indicate the presence of palaeo-oil and gas accumulation over this 70 m interval. This is consistent with the current oil show indications such as staining, cut fluorescence, mud gas and surface solvent extraction within this reservoir interval. Multiple hydrocarbon migration pathways are also indicated in sandstones of the lower Algebuckina Sandstone, basal Poolowanna Formation and Tirrawarra Sandstone equivalent. This is a significant upgrade in hydrocarbon prospectivity, given previous perceptions of relatively poor quality and largely immature source rocks in the Basin.Conventional structural targets are numerous, but the timing of hydrocarbon expulsion dictates that those with an older drape and compaction component will be more prospective than those dominated by Tertiary reactivation which may have resulted in remigration or leakage. Preference should also apply to those structures adjacent to generative source kitchens on relatively short migration pathways. Early formed stratigraphic traps at the level of the Tirrawarra Sandstone equivalent and Poolowanna Formation are also attractive targets. Cyclic sedimentation in the Poolowanna Formation results in two upward fining cycles which compartmentalise the sequence into two reservoir–seal configurations. Basal fluvial sandstone reservoirs grade upwards into topset shale/coal lithologies which form effective semi-regional seals. Onlap of the basal cycle onto the Late Triassic unconformity offers opportunities for stratigraphic entrapment.

A practical petrophysical model for a source rock play: The Mancos Shale

2017 ◽  
Vol 5 (3) ◽  
pp. T423-T435
Author(s):  
Jesús M. Salazar ◽  
Ron J. M. Bonnie ◽  
William W. Clopine ◽  
G. Eric Michael
Keyword(s):  
Source Rock ◽  
Water Saturation ◽  
Clay Content ◽  
Source Rocks ◽  
Crushed Rock ◽  
Organic Carbon Content ◽  
Hydrocarbon Generation ◽  
Niobrara Formation ◽  
Mancos Shale ◽  
Petrophysical Model

Recently, the focus in source rock exploration has moved from gas-rich to liquid-rich plays and warrants revisiting “bypassed” hydrocarbon charged source rocks, which were deemed uneconomic when first drilled. In North America’s oil fields, there are thousands of wells with different vintages of nuclear and electrical logs, yet these wells generally lack any advanced logs beyond the traditional triple combo. We have developed a workflow that uses a considerable amount of laboratory measurements made on crushed rock to upscale a petrophysical model based on a triple combo logging suite only. The model divides the field (laterally) in oil window and gas window fairways and (vertically) in petrophysical units. The remaining hydrocarbon generation potential is based on geochemical measurements, such as thermal maturity and total organic carbon content (TOC), from core and cuttings in the area. The petrophysical units reflect major geologic intervals with similar porosity and clay content. The workflow was sequentially built by correlating logs with core measurements, using TOC and maturity for organic matter, X-ray diffraction for mineralogy and grain density, porosity, and water saturation from fluids extraction, for volumetrics. The model is applied to the Mancos Shale (New Mexico, USA), a Cretaceous-age source rock, which includes the Niobrara Formation. The Mancos Shale has been penetrated in various fields while developing conventional sandstone reservoirs. The model is validated with measurements on a core recently acquired in the anticipated high-hydrocarbon-yield window. Petrophysical properties predicted from logs agree well with core measurements in blind tests, demonstrating the robustness of the model despite being based on a basic suite of logs and a simple deterministic approach. This model is now routinely used by the asset team as an automated workflow to generate fairway maps, locate sweet spots, and for landing lateral wells.

scholarly journals Paleozoic Petroleum System of Central Saudi Arabia

GeoArabia ◽  
1999 ◽  
Vol 4 (3) ◽  
pp. 321-336 ◽  
Author(s):  
Mahdi A. Abu-Ali ◽  
Jean-Luc L. Rudkiewicz ◽  
Jim G. McGillivray ◽  
Françoise Behar
Keyword(s):  
Saudi Arabia ◽  
Source Rock ◽  
Oil And Gas ◽  
First Episode ◽  
Gas Generation ◽  
Geochemical Model ◽  
Hydrocarbon Expulsion ◽  
Oil Expulsion ◽  
Oil Cracking ◽  
Secondary Cracking

ABSTRACT An integrated geochemical model was developed to reconstruct the history of expulsion, migration and entrapment of Paleozoic oil and gas in the main regional Permian Unayzah Sandstone Reservoir in Central Saudi Arabia. The model indicates that by the Late Jurassic, approximately 140 million years ago (Ma), the principal Paleozoic source rock, the Lower Silurian Qusaiba “hot” shale, was mature in the deepest hydrocarbon “kitchens”. Hydrocarbon expulsion started during the Aptian and Albian (late Early to early Middle Cretaceous, 100 to 120 Ma). Expulsion of oil and gas is linked to three geochemical events. Primary kerogen cracking led to a first episode of expulsion about 120 Ma. Secondary heavy component and oil cracking resulted in a second episode of expulsion at approximately 100 Ma. Between 20 to 10 Ma, later uplift, and the resulting pressure drop in the source rock, led to a third expulsion phase. The first two expulsion episodes were gradual, whereas the third was more rapid and related to uplift of the Arabian Arch, opening of the Red Sea and the Zagros Orogeny during the Miocene. Expulsion of oil nearly terminated after the Late Cretaceous, while gas continued to be expelled, though at a lower rate, in the Tertiary. Peak gas expulsion occurred post Early Eocene with significant gas generation from secondary cracking of oil retained in the source rock. Gas was sourced either directly from kerogen, or from secondary cracking of heavy absorbed components or non-migrated oils. The expulsion of gas coincides with oil expulsion for the first two episodes because the gas and oil formed as a single phase. As a result of Tertiary Uplift, gas separated from the oil and re-migrated in the final episode (20 to 10 Ma).

scholarly journals Source Rock Distribution and Thermal Maturity in the Southern Arabian Peninsula

GeoArabia ◽  
1998 ◽  
Vol 3 (3) ◽  
pp. 339-356
Author(s):  
Penelope A. Milner
Keyword(s):  
Saudi Arabia ◽  
United Arab Emirates ◽  
Source Rock ◽  
Structural Model ◽  
Oil And Gas ◽  
Arabian Peninsula ◽  
Source Rocks ◽  
Burial History ◽  
The North ◽  
And Migration

ABSTRACT Recent work by Phillips Petroleum in the Southern Arabian Peninsula has elucidated the source potential of the Palaeozoic strata. A group of newly drilled and older wells, together with exclusive and non-exclusive reports, have been used in order to develop improved maturation and migration models for emerging plays, and to gain a better understanding of the subsidence and maturation history of this large and diverse area. It has been possible to conduct comprehensive burial history modelling for a number of wells from Oman, Saudi Arabia and the United Arab Emirates. This, together with the modelling of hypothetical wells derived from depth structure maps, has improved our understanding of oil- and gas-prone source rocks in the Cretaceous, Jurassic and Palaeozoic strata. The resultant maturity distribution has been developed with the aid of a more detailed structural model for the Southern Arabian Peninsula. In tandem with this study, available cores and cuttings were analysed to measure source rock total organic carbon, maturity and richness parameters and summarised using proprietary techniques. It is concluded that the Jurassic Hanifa Formation is less mature and not source facies to the south and west of the Rub’ Al-Khali. The oil and gas mature source facies is present in the north and east of the Rub’ Al-Khali and in the Western Emirates. In addition, it is concluded that the oil mature Silurian source facies is confined to the narrow southern and western margins of the Rub’ Al-Khali. Outside this area the overmature area is in the core of the Rub’ Al-Khali extending northeast to the United Arab Emirates. The remaining area is modelled as gas mature in western Saudi Arabia and Qatar.

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

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 &gt; 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&lt; 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.

Dynamics of Hydrocarbon Expulsion from Shale Source Rocks

2005 ◽  
Vol 23 (5) ◽  
pp. 333-355 ◽  
Author(s):  
Xiongqi Pang ◽  
Zhenxue Jiang ◽  
Shengjie Zuo ◽  
Ian Lerche
Keyword(s):  
Source Rock ◽  
Driving Forces ◽  
Water Solution ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Two Factors ◽  
Hydrocarbon Expulsion

Expulsion of hydrocarbons from a shale source rock can be divided in four stages. In the first stage, only a small amount of hydrocarbons can be expelled in water solution and by diffusion. Compaction and hydrocarbon concentration gradient are the major driving forces, whereas their corresponding hydrocarbon expulsion amounts make up 30% and 70% to the total, respectively. In the second stage, in addition to transport by water solution and by diffusion, source rocks expel a large quantity of gas in free phase. In the third stage, the most important feature is that source rocks expel oil as a separate phase and gas in oil solution. Hydrocarbon expulsion by diffusion through the source rock organic network, dehydration of clay minerals, and thermal expansion of fluids and rocks are the three major driving forces in the second and the third stages, whereas the corresponding hydrocarbon expulsion accounts for 40–60%, 10–20%, and 5–10%, respectively, of the total amount expelled. In the fourth stage, source rocks mainly expel dry gas as a free phase. Volume expansion of kerogen products and capillary force are the two major driving forces for hydrocarbon expulsion. The expulsion accounts for 60% and 30% to the total gas expulsion of this stage, respectively, for each driving force. Hydrocarbon expulsion, including the hydrocarbon expulsion threshold (HET), the relative phases and the dynamics, are controlled by two factors: the hydrocarbon generation amount, and the ability of source rocks to retain hydrocarbons. Source rocks cross the HET and begin to expel a large quantity of hydrocarbons when the generated hydrocarbons have met all of the needs for hydrocarbon retention. HET is divides the processes of hydrocarbon expulsion into the various four stages.

The Geochemical Characteristics of High Quality Hydrocarbon Source Rocks - A Case Study of Hailaer Basin

2013 ◽  
Vol 868 ◽  
pp. 107-112
Author(s):  
Dan Ning Wei ◽  
Gui Lei Wang
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Geochemical Characteristics ◽  
Source Rocks ◽  
Common Source ◽  
Hydrocarbon Source Rock ◽  
High Quality ◽  
Hydrocarbon Source Rocks ◽  
Study Zone ◽  
Hydrocarbon Expulsion

The distribution of high quality hydrocarbon source rocks plays an important role in the accumulation of oil and gas. As a result, the identification of geochemical characteristics of high quality source rocks is the key to discriminate the distribution of high quality source rocks accurately. By core observation and sample analysis, taking Wuerxun-Beier depression in Hailaer Basin as the target regions, we make accurate discrimination of high quality hydrocarbon source rock developmental characteristics and comparison with common source rocks. The research shows that: (1) the hydrocarbon expulsion efficiency in study zone is high due to the alternating deposits of high quality hydrocarbon source rocks and sandstones. The high quality hydrocarbon source rocks deposited in the reducing environment to strong reducing ones, whereas common rocks deposited in oxidizing environment to weak oxidizing ones. (2) the occurrence of organic matter of high quality hydrocarbon source rocks is mainly in stratified enrichment type. The organic matter develops parallel bedding or basic parallel bedding. However, the distribution of organic matter of common source rocks is porphyritic and heterogeneous, or interrupted lamellar. (3) the hydrocarbon potential of high quality hydrocarbon source rocks is more than ten times that of common source rocks. (4) the content of organic carbon in high quality source rocks is high and the content of chloroform asphalt A is relatively low, which reflects that the hydrocarbon expulsion efficiency of high quality source rocks in the sand-shale interbeds of study zone is high.

Sign in / Sign up

Export Citation Format

Share Document