Could a structurally controlled, hydrothermal dolomite play be operative in Cambro-Ordovician carbonates of the southern Georgina Basin, Queensland?

2016 ◽  
Vol 56 (2) ◽  
pp. 535
Author(s):  
Robbert J. Willink ◽  
Mike J. Bucknill ◽  
Nathan C. Palmer
Keyword(s):  
Fluid Flow ◽  
Seismic Data ◽  
Hydrothermal Fluid ◽  
Oil And Gas ◽  
Fault Zones ◽  
Tight Carbonate ◽  
Porosity And Permeability ◽  
Platform Carbonates ◽  
Hydrothermal Dolomite ◽  
Porosity Development

Hydrothermal dolomitisation of carbonates can create zones of favourable porosity and permeability in otherwise tight carbonate successions. In North America, a number of fields produce oil and gas from such reservoirs that developed along and adjacent to pre-existing fault zones acting as loci for hydrothermal fluid flow. Seismic data across these North American fields are characterised by linear zones of disturbance evident along fault zones where porosity development has occurred. Similar zones of disturbance have been observed on newly acquired seismic over the Toko Syncline in Queensland. Here, these zones extend through a thick Cambro-Ordovician carbonate succession that includes platform carbonates of the Thorntonia Limestone, overlying deeper water deposits of the Arthur Creek Formation that are organic rich and hydrocarbon generative at their base, and also in younger shallow water carbonates of the Arrinthrunga, Ninmaroo, Kelly Creek and Coolibah formations. If these zones of disturbance on seismic also reflect the development of hydrothermal dolomite reservoirs, they provide a new exploration target in the southern Georgina Basin.

Using Logging and Seismic Data to Identify Boundaries Between Different OWC Units in a Deepwater Carbonate Reservoirs

2021 ◽  
Author(s):  
Kangxu Ren ◽  
Junfeng Zhao ◽  
Jian Zhao ◽  
Xilong Sun
Keyword(s):  
Seismic Data ◽  
Carbonate Rocks ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Sedimentary Process ◽  
Core Samples ◽  
Tight Carbonate ◽  
Porosity And Permeability ◽  
Seismic Sections ◽  
Parameters Inversion

Abstract At least three very different oil-water contacts (OWC) encountered in the deepwater, huge anticline, pre-salt carbonate reservoirs of X oilfield, Santos Basin, Brazil. The boundaries identification between different OWC units was very important to help calculating the reserves in place, which was the core factor for the development campaign. Based on analysis of wells pressure interference testing data, and interpretation of tight intervals in boreholes, predicating the pre-salt distribution of igneous rocks, intrusion baked aureoles, the silicification and the high GR carbonate rocks, the viewpoint of boundaries developed between different OWC sub-units in the lower parts of this complex carbonate reservoirs had been better understood. Core samples, logging curves, including conventional logging and other special types such as NMR, UBI and ECS, as well as the multi-parameters inversion seismic data, were adopted to confirm the tight intervals in boreholes and to predicate the possible divided boundaries between wells. In the X oilfield, hundreds of meters pre-salt carbonate reservoir had been confirmed to be laterally connected, i.e., the connected intervals including almost the whole Barra Velha Formation and/or the main parts of the Itapema Formation. However, in the middle and/or the lower sections of pre-salt target layers, the situation changed because there developed many complicated tight bodies, which were formed by intrusive diabase dykes and/or sills and the tight carbonate rocks. Many pre-salt inner-layers diabases in X oilfield had very low porosity and permeability. The tight carbonate rocks mostly developed either during early sedimentary process or by latter intrusion metamorphism and/or silicification. Tight bodies were firstly identified in drilled wells with the help of core samples and logging curves. Then, the continuous boundary were discerned on inversion seismic sections marked by wells. This paper showed the idea of coupling the different OWC units in a deepwater pre-salt carbonate play with complicated tight bodies. With the marking of wells, spatial distributions of tight layers were successfully discerned and predicated on inversion seismic sections.

scholarly journals PROSPECTS FOR OIL AND GAS PRESENCE IN THE SOUTH-EASTERN PART OF THE INNER FLYSCH COVERS OF THE UKRAINIAN CARPATHIANS

2019 ◽  
Vol 4 (181) ◽  
pp. 5-16
Author(s):  
Myroslav PAVLYUK ◽  
Volodymyr SHLAPINSKY ◽  
Olesya SAVCHAK ◽  
Myroslav TERNAVSKY ◽  
Lyubov HUZARSKA ◽  
...  
Keyword(s):  
Seismic Data ◽  
Hydrothermal Fluid ◽  
Large Scale ◽  
Oil And Gas ◽  
Significant Rise ◽  
Gas Composition ◽  
The South ◽  
Eastern Sector ◽  
South Eastern ◽  
The Given

We have studied the Cretaceous and Paleogene flysch of the Duklya-Chornohora, Burkut, Rakhiv, Marmarosh and Pieniny covers that in the south-eastern sector of the Ukrainian Carpathians near the Romanian border (Hutsulian segment) distinguish themselves by very inclined overthrust. Spatially the given tectonic units are in so-called hydrothermal fluid, unfavourable on the whole as to the presence of hydrocarbons in it on a large scale. But, within its limits the plots, small in area, with hydrocarbon prevalence in the gas composition are distinguished. Prospects for gas presence in the region should be connected with those of them that spatially are drown to the Transcarpathian trough. One such section is the Velikobychkovk sector of the Monastyretsky sub-cover, where it is proposed to lay a parametric well 1-Velikiy Bychkov, in order to reveal the possible para-autochthon of the Vezhany sub-cover and the Paleogene of the Dilovetsky sub-cover. In addition, according to seismic data, a significant rise in the pre-flysch base is forecast in this section of the Carpathians under the Marmarosh cover. The roof of this foundation at the location of the recommended well 1-Velikiy Bychkov may be at a depth of 5000–5500 m. It may be represented by the youngest deposits of the pre-Alpine complex – the Triassic strata, industrially oil and gas saturated in the neighboring countries.

THE SOUTHERN BONAPARTE GULF BASIN - NEW PLAYS

1990 ◽  
Vol 30 (1) ◽  
pp. 52
Author(s):  
J.M. Durrant ◽  
R.E. France
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Well Control ◽  
Lost Circulation ◽  
Marine Source ◽  
Porosity And Permeability ◽  
Basin Floor ◽  
Relationship Of ◽  
New Phase ◽  
Live Oil

Integration of regional exploration data with a new basin model involving progressive basinward salt withdrawal has generated new exploration plays in WA-128-P and WA-211-P, which forms part of the offshore Southern Bonaparte Gulf. This area provides a hydrocarbon habitat that is unique to this part of the Bonaparte Gulf Basin.Three major Palaeozoic megasequences, MS-I, MS-II (A & B) and MS-III, are identified on seismic data and correspond to major stages in the structural and depositional development of the basin, from Silurian through to Triassic times.Early exploration, targeted on structural highs, encountered numerous hydrocarbon shows. Of most recent significance are the Turtle-1 and Turtle-2 wells. Turtle-1 (1984) targeted a midbasin, MS-I high and recovered oil in MS-III. Turtle-2 (1989) tested an additional 510 m-thick, MSII onlap sequence and encountered, within fractured intervals, significant oil and gas influx accompanied by massive lost circulation. Significant live oil was produced on test despite huge damage inflicted to the fracture porosity and permeability during the fourteen-day well control period.Recent geochemical work indicates that the oils recovered from MS-II and MS-III have a common marine source. Oils from MS-III are associated with incompetent seals and meteoric waters and are variably degraded and exhibit low GOR. In contrast, oils of MS-II, associated with competent seals, exhibit high GOR. In consequence, a diversity of new exploratory plays are indicated:Fractured reservoirs in MS-II, stratigraphic onlaps flanking MS-I structures.Stacked turbidites and basin floor fans deposited in the MS-II salt-withdrawal sub-basins.Carbonate banks within the MS-II sub-basin's marginal carbonate complexes.MS-I carbonate structures localised over early salt structures and onlapped by MS-II sediments.Structural and stratigraphic traps of MS-II and III associated with diapiric salt.By virtue of the stratigraphic and structural relationship of MS-II sediments which onlap the flanks of structural highs, these plays have not been previously drilled in optimal locations. Consequently, a new phase of exploration specifically targeted at these plays is now planned to proceed in parallel with exploration of MS-III targets in structural traps. The application of the basin model concepts to these MS-III plays has revealed subtle crestal faulting associated with structural highs. The structural and stratigraphic implications of these observations indicate new plays on the flanks of previously drilled structures.

Geometrical comparison of outcrop data and discrete element models of extensional fault zones in layered carbonates

2020 ◽  
Author(s):  
Hagen Deckert ◽  
Steffen Abe ◽  
Wolfgang Bauer
Keyword(s):  
Fluid Flow ◽  
Fault Zone ◽  
Seismic Data ◽  
Discrete Element ◽  
Fault Zones ◽  
Normal Faults ◽  
Small Displacement ◽  
Small Scale ◽  
Burial Depth ◽  
Multiple Fault

<p>In the course of hydrocarbon or geothermal exploration the characterisation of fault zone architectures is of interest for fluid flow modelling and geomechanical studies. Seismic data normally offer the best information for the identification of fault zone geometries in sedimentary basins. However, the internal structure or the damage zone of a fault can be hardly resolved with seismic data as displacements along single fault strands or fractures are by far too small. Thus, it is not possible to directly map small scale faults with seismic methods, though these structures might significantly influence fluid flow. We try to examine the architecture of extensional fault zones in carbonate rocks at subseismic scales by using discrete element method (DEM) techniques to numerically simulate the evolution of fault zones including their associated damage zones.</p><p>As a case study we have analysed the geometry, displacement and fault width of normal faults in fine grained jurassic limestones in a quarry in Franconia, Germany. The quarry shows a rather simple set of conjugated 60deg dipping normal faults. Displacement is rather small and varies between c. 5cm up to c. 2m, some faults show almost no offset. The fault thickness varies between 2cm and c. 1m. A closer investigation of the fault geometries reveals, next to planar parts, sometimes complex fault zone structures including restraining and releasing bends, multiple fault strands as well as lenses and associated riedel shears. Analysis of high resolution photogrammetric data revealed a high number of small scale fractures between neighbouring discrete fault surfaces which are interpreted as highly fractured damage zones. Some faults with rather small displacement suggest that the overall inclination of the fault is a result of small subvertical sections which are connected in a staircase like appearance. </p><p>The DEM models simulate normal faulting in a layered marl-limestone sequence driven by the displacement of an underlying basement fault. Different layer geometries and effective vertical stresses in the range of 15-45 MPa, equivalent to an overburden thickness of c. 1000-3000m, have been used in the models. The stress range covers the maximum burial depth of the carbonates, which is assumed to be c. 1500m. Material properties used in the DEM were calibrated based on laboratory data, i.e. results of triaxial deformation tests on the studied limestones.</p><p>Results of the models show fault geometries which resemble those observed in the studied outcrop. In particularly under low stress, small offsets and with strongly decoupled layers we observe steeply dipping faults (>70deg) which also show staircase structures composed of sub-vertical fractures within each of the layers and horizontal offsets along the layer interfaces. We also observe the development of multiple fault strands and associated damage zones. </p><p>Our study shows that the DEM models are capable to reproduce observed fault geometries and damage zones. The results help to understand fault zone architectures and depict highly fractured areas in a sub-seismic scale.</p>

Significance of Mineralogical and Lithologic-Petrographical Rank in the Ranking of Geological Information

2020 ◽  
Vol 42 (4) ◽  
pp. 33-49
Author(s):  
O.V. CHEPIZHKO ◽  
V.V. YANKO ◽  
V.M. KADURIN ◽  
I.M. NAUMKO ◽  
S.M. SHATALIN
Keyword(s):  
Fluid Flow ◽  
Black Sea ◽  
Bottom Sediments ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Geochemical Characteristics ◽  
The Black Sea ◽  
Flow Parameters ◽  
Geochemical Parameters ◽  
Geological Information

For the first time the importance of mineralogical and lithological-petrographical ranks in the line of geological information ranks is substantiated for implementation of long-term forecasts, standard and non-standard approaches to research of physical and geochemical parameters as a basis of creation of complex system of forecast criteria and prospecting indicators of hydrocarbons within the sedimentary cover of Black sea based on the theory of global fluid-flows derivation. These criteria have different sensitivity to the object (hydrocarbon deposits) and are therefore ranked. The ranking determined the following parameters: 1) seismic data within the object, obtained by the method of deep seismic sounding, RWM SDP; 2) parameters of tectono-geodynamic structures; 3) the main characteristics of sedimentary cover and bedrock; 4) geochemical characteristics; 5) parameters of mineral complexes and fluid inclusions in mineral neoformations; 6) the value of the distribution of meiobenthos. Based on modern views of oil and gas geology, structural-tectonic and lithological-facies criteria are among the main ones. The study of the mineralogical component of sediments is made with using mineralogical, thermobarogeochemical and X-ray spectral methods. Fixation of anomalies of fluid flow at the bottom of the Black Sea as to the distribution of abiotic parameters in order to assess the prospects of oil and gas is determined by structural and tectonic features and high permeability of fluid flow; parameters of mineral complexes (minerals, facies) and genetic connections; heterogeneity of geochemical characteristics of bottom sediments; the presence of hydrocarbon inclusions in authigenic minerals of bottom sediments.

About this title - Seismic Characterization of Carbonate Platforms and Reservoirs

10.1144/sp509 ◽  
2021 ◽  
Vol 509 (1) ◽  
pp. NP-NP
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Carbonate Platform ◽  
Carbonate Platforms ◽  
Oil And Gas Exploration ◽  
Seismic Modelling ◽  
Flow Units ◽  
Development Data ◽  
Seismic Characterization

Modern seismic data have become an essential toolkit for studying carbonate platforms and reservoirs in impressive detail. Whilst driven primarily by oil and gas exploration and development, data sharing and collaboration are delivering fundamental geological knowledge on carbonate systems, revealing platform geomorphologies and how their evolution on millennial time scales, as well as kilometric length scales, was forced by long-term eustatic, oceanographic or tectonic factors. Quantitative interrogation of modern seismic attributes in carbonate reservoirs permits flow units and barriers arising from depositional and diagenetic processes to be imaged and extrapolated between wells.This volume reviews the variety of carbonate platform and reservoir characteristics that can be interpreted from modern seismic data, illustrating the benefits of creative interaction between geophysical and carbonate geological experts at all stages of a seismic campaign. Papers cover carbonate exploration, including the uniquely challenging South Atlantic pre-salt reservoirs, seismic modelling of carbonates, and seismic indicators of fluid flow and diagenesis.

scholarly journals The structure of the sedimentary complex of the Middle and South Caspian depressions (Azerbaijan sector)

2021 ◽  
Vol 43 (4) ◽  
pp. 199-216
Author(s):  
N.P. Yusubov ◽  
I.S. Guliyev
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Clay Content ◽  
Geological Structure ◽  
Point Of View ◽  
South Caspian Basin ◽  
Origin And Evolution ◽  
Geological Interpretation ◽  
High Degree

The high degree of knowledge of the upper horizons of the sedimentary cover of the Middle and South Caspian depressions, given an insufficient increase in hydrocarbon reserves, leads to the need for a detailed approach to the search for oil and gas deposits in deep-seated sediments (over 6 km). During the geological interpretation of new highly informative seismic data, as well as data of deep drilling and petrological core studies, there were revealed obvious shortcomings in the concepts of the origin and evolution of the Middle and South Caspian depressions. These ideas misinterpret evolution, especially the South Caspian Basin, which is characterized by a number of unique features: very thick sedimentary cover (up to 22 km), extremely high sedimentation rate, low heat flow and reservoir temperatures, abnormally high pore and reservoir pressures, high clay content of the section, etc. The main purpose of the study was to elucidate the regional structure and features of the dissection of the sedimentary cover of the Middle and South Caspian depressions, the conditions of occurrence and distribution of facies and thicknesses of individual complexes of deposits. The paper analyzes the results of some previous studies of the geological structure of the Middle and South Caspian depressions based on the data of deep seismic sounding, seismological and gravimetric observations. We consider the main conclusions of these studies, about the geological structure of the sedimentary complex of the region’s, very outdated and subject to revision. The results of seismic stratigraphic analysis of seismic data allowed the authors to identify new data about the tectonic structure and express a completely different point of view regarding the structure of the sedimentary cover in the region. The work also touches on the issue associated with the tectonics of the region and the alleged subduction zone here.

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