FRACTALS AND SECONDARY MIGRATION

Fractals ◽  
1995 ◽  
Vol 03 (04) ◽  
pp. 799-806 ◽  
Author(s):  
PAUL MEAKIN ◽  
GERI WAGNER ◽  
VIDAR FRETTE ◽  
JENS FEDER ◽  
TORSTEIN JØSSANG
Keyword(s):  
Oil And Gas ◽  
Fractal Model ◽  
Source Rocks ◽  
Fracture Aperture ◽  
Low Density ◽  
Secondary Migration ◽  
Gravity Driven ◽  
And Migration ◽  
Water Saturated ◽  
Wetting Fluid

The process of secondary migration, in which oil and gas are transported from the source rocks, through water saturated sedimentary carrier rocks, to a trap or reservoir can be described in terms of the gravity driven penetration of a low-density non-wetting fluid through a porous medium saturated with a wetting fluid. This process has been modeled in the laboratory and by computer simulations using homogeneous porous media. Under these conditions, the pattern formed by the migrating fluid can be described in terms of a string of fractal blobs. The low density internal structure of the fractal blobs and the concentration of the transport process onto the self-affine strings of blobs (migration channels) both contribute to the small effective hydrocarbon saturation in the carrier rocks. This allows the hydrocarbon fluids to penetrate the enormous volume of carrier rock without all of the hydrocarbon being trapped in immobile isolated bubbles. In practice, heterogeneities in the carrier rocks play an important role. In some cases, these heterogeneities can be represented by fractal models and these fractal heterogeneity models provide a basis for more realistic simulations of secondary migration. Fractures may play a particularly important role and migration along open fractures was simulated using a self-affine fractal model for the fluctuating fracture aperture.

Eromanga (Queensland) exploration–new concepts for an old basin

2011 ◽  
Vol 51 (1) ◽  
pp. 333
Author(s):  
David Lowry ◽  
David Evans
Keyword(s):  
Oil And Gas ◽  
Oil Field ◽  
Secondary Migration ◽  
New Concepts ◽  
Oil Generation ◽  
And Migration ◽  
Oil Expulsion ◽  
Sonic Logs ◽  
Southern Flank ◽  
Eromanga Basin

Eromanga Basin exploration surged in Queensland after the discovery of the Jackson field in 1982, but has ebbed over the last 20 years. Perceived exploration risks are: • Oil generation and migration peaked in the mid-Cretaceous before much of the anticlinal structuring, so that modern structure is an uncertain guide to Cretaceous migration paths. • Permian coals are generally credited with sourcing most of the oil and gas in the Cooper-Eromanga Basin. In Queensland, the Permian largely drains to the southern flank and the northern flank is thought to have a high charge risk. This study covers 100,000 km2. It used sonic logs to determine the amount of Tertiary erosion and thus allows the preparation of structure maps restored to mid-Cretaceous time. Maturity maps of the Birkhead and Poolowanna Formations were computed from a reflectance/restored temperature algorithm based on 50 wells. Source rock thickness maps and an oil expulsion model based on Pepper and Corvi (1995a, 1995b) then allowed oil expulsion to be mapped regionally. The study produces the key results that could be expected from 3D earth modelling, but with great savings in time and money. The study demonstrates an oil kitchen at both Poolowanna and Birkhead stratigraphic levels in the vicinity of Tanbar–1. Secondary migration losses are speculative, but modelling shows that hundreds of millions of barrels of oil from each formation have migrated west towards the Curalle ridge, north to Inland and Morney, and southeast to Mt Howitt. The Inland oil field is presently an isolated anomaly on the northwest flank of the basin, but this study suggests that further exploration in the area could be successful.

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.

scholarly journals Petroleum system modeling in cenozoic sediments, Block 05-1a, Nam Con Son Basin

2017 ◽  
Vol 20 (K4) ◽  
pp. 91-102
Author(s):  
Xuan Van Tran ◽  
Huy Nhu Tran ◽  
Chuc Dinh Nguyen ◽  
Tuan Nguyen ◽  
Ngoc Ba Thai ◽  
...  
Keyword(s):  
Source Rock ◽  
Oil And Gas ◽  
System Modeling ◽  
Model Development ◽  
Source Rocks ◽  
Early Miocene ◽  
North East ◽  
Petroleum System Modeling ◽  
And Migration ◽  
Migration Pathways

Based on the update of exploration data the oil and gas potential within block 05-1 are studied through define the source rocks, Hydrocarbon (HC) generation, expulsion and migration, focusing on source rock Oligocene /Early Miocene and Middle Miocene; Define the accumulation of hydrocarbon in Lower Miocene targets; The results of assessments for source rock, oil sampling analysis is used to determine the relationship between in–situ oil or oil migrated from other places. The workflow of basin modeling is assigned to get output (migration pathways, volume of accumulation), as well as data calibration. Main source rocks include H150, H125 shales and H150 coal with Total organic carbon (TOC)~1 and 47 respectively. These source rocks are medium to good potential. At the present time, most of the source rocks are in oil window, while the deep parts is in gas window. Oil started to be generated in Early Miocene, and started to be expulsed in Late Miocene. Gas started to be generated in Quaternary, about to be expulsed. The oil migrated mainly from the troughs at the West and minorly from the East and South to Dai Hung High. Gas started to migrate from West to East and South West to North East at the Western part. However, at the Eastern part, gas migrated from the opposite direction. The results of sensitive analyses show more oil in max source rock case, therefore, a 3D model development is recommended and identify the differences in generation characteristics between Nam Con Son and Cuu Long basins.

scholarly journals Petroleum generation and migration in the Mesopotamian Basin and Zagros Fold Belt of Iraq: results from a basin-modeling study

GeoArabia ◽  
2004 ◽  
Vol 9 (4) ◽  
pp. 41-72 ◽  
Author(s):  
Janet K. Pitman ◽  
Douglas Steinshouer ◽  
Michael D. Lewan
Keyword(s):  
Late Cretaceous ◽  
Oil And Gas ◽  
Source Rocks ◽  
Peak Oil ◽  
Fold Belt ◽  
Hydrous Pyrolysis ◽  
Oil Generation ◽  
Petroleum Generation ◽  
And Migration ◽  
Migration Pathways

ABSTRACT A regional 3-D total petroleum-system model was developed to evaluate petroleum generation and migration histories in the Mesopotamian Basin and Zagros fold belt in Iraq. The modeling was undertaken in conjunction with Middle East petroleum assessment studies conducted by the USGS. Regional structure maps, isopach and facies maps, and thermal maturity data were used as input to the model. The oil-generation potential of Jurassic source-rocks, the principal known source of the petroleum in Jurassic, Cretaceous, and Tertiary reservoirs in these regions, was modeled using hydrous pyrolysis (Type II-S) kerogen kinetics. Results showed that oil generation in source rocks commenced in the Late Cretaceous in intrashelf basins, peak expulsion took place in the late Miocene and Pliocene when these depocenters had expanded along the Zagros foredeep trend, and generation ended in the Holocene when deposition in the foredeep ceased. The model indicates that, at present, the majority of Jurassic source rocks in Iraq have reached or exceeded peak oil generation and most rocks have completed oil generation and expulsion. Flow-path simulations demonstrate that virtually all oil and gas fields in the Mesopotamian Basin and Zagros fold belt overlie mature Jurassic source rocks (vertical migration dominated) and are situated on, or close to, modeled migration pathways. Fields closest to modeled pathways associated with source rocks in local intrashelf basins were charged earliest from Late Cretaceous through the middle Miocene, and other fields filled later when compression-related traps were being formed. Model results confirm petroleum migration along major, northwest-trending folds and faults, and oil migration loss at the surface.

Fracture stratigraphy, fault architecture and DFN modeling of both diffuse and localized fracture networks

2020 ◽  
Author(s):  
Fabrizio Agosta
Keyword(s):  
Oil And Gas ◽  
Damage Zone ◽  
Fracture Network ◽  
Fracture Aperture ◽  
Fracture Networks ◽  
Present Contribution ◽  
Fracture Porosity ◽  
Fractured Limestone ◽  
And Migration ◽  
Fault Architecture

<p>Quantification of the geometry, distribution, and dimension of fracture networks is key to fully understand the petrophysical properties of outcrop-to-reservoir scales rock volumes. On these regards, Discrete Fracture Network (DFN) modeling is a very useful tool to compute the values of fracture porosity and equivalent permeability of geo-cellular volumes populated with stochastic or deterministic fracture networks. Independently of their size and cell dimensions, the single geocelullar volumes are populated by inputting the following parameters for each fracture set: (i) length; (ii) aspect ratio; (iii) mechanical and hydraulic apertures; (iv) fracture intensity, and (v) attitude. A sensitivity analysis is always carried out in order to test the seeding procedure of the employed software, and to check the validity of the fracture aperture values employed as input data. The latter values, in fact, are the most critical to assess from outcrop and laboratory analyses. The present contribution focuses on the results of recent works performed on the fractured limestone rocks of the Apulian Platform, which are widely exposed along the Italian peninsula. Outcrops are first introduced in order to define the fracture stratigraphy and fault architecture of the Meso-Cenozoic limestone rocks. Then, the criteria behind the construction of DFN models are illustrated. Methods employed for the build of individual fracture units and single fault damage zone domains are illustrated. Finally, the computed values of fracture porosity and equivalent horizontal permeability obtained for multiple DFN models are presented. Discussion of the data focuses on the fluid accumulation and migration properties of the fractured limestone rocks by considering their amount of exhumation experienced during Plio-Quaternary times. Results of DFN modeling could be helpful to optimize the appraisal and development operations of hydrocarbon reservoirs, and minimize the pollution of freshwater aquifer. In fact, the Apulian carbonates host in the underground significant amounts of freshwater of the Mediterranean Region, and the largest oil and gas reserves of continental Europe. Furthermore, the results could shed new lights into the role exerted by faults and fractures on subsurface CO<sub>2</sub> storage in depleted carbonate reservoirs, a practice that envisioned to decrease the greenhouse gas concentration in the atmosphere in the next future.</p>

scholarly journals A review of oil and gas seepage in the Nuussuaq Basin, West Greenland – implications for petroleum exploration

2020 ◽  
Author(s):  
Flemming G. Christiansen ◽  
Jørgen A. Bojesen-Koefoed ◽  
Gregers Dam ◽  
Troels Laier ◽  
Sara Salehi
Keyword(s):  
Structural Model ◽  
Oil And Gas ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Lateral Migration ◽  
West Greenland ◽  
Gas Seepage ◽  
Petroleum Generation ◽  
And Migration ◽  
Migration Pathways

The Nuussuaq Basin in West Greenland has an obvious exploration potential. Most of the critical elements are well documented, including structures that could form traps, reservoir rocks, seals and oil and gas seepage that documents petroleum generation. And yet, we still lack a full understanding of the petroleum systems, especially the distribution of mature source rocks in the subsurface and the vertical and lateral migration of petroleum into traps. A recently proposed anticlinal structural model could be very interesting for exploration if evidence of source rocks and migration pathways can be found. In this paper, we review all existing, mostly unpublished, data on gas observations from Nuussuaq. Furthermore, we present new oil and gas seepage data from the vicinity of the anticline. Occurrence of gas within a few kilometres on both sides of the mapped anticline has a strong thermogenic fingerprint, suggesting an origin from oil-prone source rocks with a relatively low thermal maturity. Petroleum was extracted from an oil-stained hyaloclastite sample collected in the Aaffarsuaq valley in 2019, close to the anticline. Biomarker analyses revealed the oil to be a variety of the previously characterised “Niaqornaarsuk type,” reported to be formed from Campanian-age source rocks. Our new analysis places the “Niaqornaarsuk type” 10 km from previously documented occurrences and further supports the existence of Campanian age deposits developed in source rock facies in the region.

THE PROBLEMS OF DETERMINING THE CONTENT OF KEROGEN IN THE OIL AND GAS SOURCE ROCKS

2019 ◽  
pp. 69-74
Author(s):  
N.I. Samokhvalov ◽  
◽  
K.V. Kovalenko ◽  
N.A. Skibitskaya ◽  
◽  
...  
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Gas Source

Stratigraphic Intervals for Oil and Tar Sand Deposits in the Uinta Basin, Utah

2017 ◽  
Vol 54 (4) ◽  
pp. 227-264
Author(s):  
Ronald Johnson ◽  
Justin Birdwell ◽  
Paul Lillis
Keyword(s):  
Brackish Water ◽  
Source Rocks ◽  
Uinta Basin ◽  
Green River ◽  
Reservoir Rocks ◽  
Stratigraphic Framework ◽  
Two Samples ◽  
The Rich ◽  
And Migration ◽  
Almost All

To better understand oil and bitumen generation and migration in the Paleogene lacustrine source rocks of the Uinta Basin, Utah, analyses of 182 oil samples and tar-impregnated intervals from 82 core holes were incorporated into a well-established stratigraphic framework for the basin. The oil samples are from the U.S. Geological Survey Energy Resources Program Geochemistry Laboratory Database; the tar-impregnated intervals are from core holes drilled at the Sunnyside and P.R. Spring-Hill Creek tar sands deposits. The stratigraphic framework includes transgressive and regressive phases of the early freshwater to near freshwater lacustrine interval of Lake Uinta and the rich and lean zone architecture developed for the later brackish-to-hypersaline stages of the lake. Two types of lacustrine-sourced oil are currently recognized in the Uinta Basin: (1) Green River A oils, with high wax and low β-carotane contents thought to be generated by source rocks in the fresh-to-brackish water lacustrine interval, and (2) much less common Green River B oils, an immature asphaltic oil with high β-carotane content thought to be generated by marginally mature to mature source rocks in the hypersaline lacustrine interval. Almost all oil samples from reservoir rocks in the fresh-to-brackish water interval are Green River A oils; however four samples of Green River A oils were present in the hypersaline interval, which likely indicates vertical migration. In addition, two samples of Green River B oil are from intervals that were assumed to contain only Green River A oil. Tar sand at the P.R. Spring-Hill Creek deposit are restricted to marginal lacustrine and fluvial sandstones deposited during the hypersaline phase of Lake Uinta, suggesting a genetic relationship to Green River B oils. Tar sand at the Sunnyside deposit, in contrast, occur in marginal lacustrine and alluvial sandstones deposited from the early fresh to nearly freshwater phase of Lake Uinta through the hypersaline phase. The Sunnyside deposit occurs in an area with structural dips that range from 7 to 14 degrees, and it is possible that some tar migrated stratigraphically down section.

scholarly journals Prospects of Using Hydrocarbon Deposits from the Autochthonous Miocene Formation (Eastern Carpathian Foredeep, Poland) for Geothermal Purposes

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3102
Author(s):  
Anna Chmielowska ◽  
Anna Sowiżdżał ◽  
Barbara Tomaszewska
Keyword(s):  
Oil And Gas ◽  
Geothermal System ◽  
Vast Number ◽  
Hydrocarbon Traps ◽  
Oil And Gas Fields ◽  
Geothermal Potential ◽  
Carpathian Foredeep ◽  
And Migration ◽  
Gas Fields ◽  
Geothermal Parameters

There are many oil and gas fields around the world where the vast number of wells have been abandoned or suspended, mainly due to the depletion of reserves. Those abandoned oil and gas wells (AOGWs) are often located in areas with a prospective geothermal potential and might be retrofitted to a geothermal system without high-cost drilling. In Poland, there are thousands of wells, either operating, abandoned or negative, that might be used for different geothermal applications. Thus, the aim of this paper is not only to review geothermal and petroleum facts about the Eastern Carpathian Foredeep, but also to find out the areas, geological structures or just AOGWs, which are the most prospective in case of geothermal utilization. Due to the inseparability of geological settings with both oil and gas, as well as geothermal conditionings, firstly, the geological background of the analyzed region was performed, considering mainly the autochthonous Miocene formation. Then, geothermal and petroleum detailed characteristics were made. In the case of geothermal parameters, such as formation’s thickness, temperatures, water-bearing horizons, wells’ capacities, mineralization and others were extensively examined. Considering oil and gas settings, insights into reservoir rocks, hydrocarbon traps and migration paths issues were created. Then, for evaluating geothermal parameters for specific hydrocarbon reservoirs, their depths were established based on publicly available wells data. Thereafter, the average temperatures for selected reservoirs were set. As the effect, it turned out that most of the deposits have average temperatures of 40/50 °C, nonetheless, there are a few characterized by higher (even around 80 °C) temperatures at reasonable depths.

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