scholarly journals Reservoir characterisation of the Patchawarra Formation within a deep, basin-margin gas accumulation

2014 ◽  
Vol 54 (1) ◽  
pp. 45 ◽  
Author(s):  
Tim Stephens ◽  
Brenton Richards ◽  
Joseph Lim

An exploration program to assess the basin-centred gas (BCG) and stratigraphic trap potential of the Mettika Embayment in the southern Cooper Basin resulted in the discovery of gas at Hornet–1 and Kingston Rule–1. The embayment is a confined fluvial sedimentary depocentre surrounded by prolific gas fields producing from structurally closed anticlines. Gas pay was identified and both wells produced sustained gas flows to surface of between 1.2 and 2.2 MMscf/d after fracture stimulation. Core collected from the Patchawarra Formation sandstone reservoir was analysed to constrain the depositional environment and establish petrophysical properties by routine and special core analysis. An integrated reservoir study was undertaken to understand depositional setting, reservoir architecture, trapping mechanisms, permeability, and saturation controls on productivity. Gas identified in the embayment appears to have accumulated in subtle stratigraphic and combination structural traps against the flanks of existing fields and does not display the geological and physical characteristics of a BCG play. The impact and analysis of hydrocarbon migration and reservoir trapping influences in this basin-margin gas accumulation may be applicable to other under-explored flank and trough plays of the Cooper Basin.

2001 ◽  
Vol 41 (1) ◽  
pp. 185 ◽  
Author(s):  
R.R. Hillis ◽  
J.G.G. Morton ◽  
D.S. Warner ◽  
R.K. Penney

Deep basin hydrocarbon accumulations have been widely recognised in North America and include the giant fields of Elmworth and Hoadley in the Western Canadian Basin. Deep basin accumulations are unconventional, being located downdip of water-saturated rocks, with no obvious impermeable barrier separating them. Gas accumulations in the Nappamerri Trough, Cooper Basin, exhibit several characteristics consistent with North American deep basin accumulations. Log evaluation suggests thick gas columns and tests have recovered only gas and no water. The resistivity of the entire rock section exceeds 20 Ωm over large intervals, and, as in known deep basin accumulations, the entire rock section may contain gas. Gas in the Nappamerri Trough is located within overpressured compartments which witness the hydraulic isolation necessary for gas saturation outside conventional closure. Furthermore, the Nappamerri Trough, like known deep basin accumulations, has extensive, coal-rich source rocks capable of generating enormous hydrocarbon volumes. The above evidence for a deep basin-type gas accumulation in the Nappamerri Trough is necessarily circumstantial, and the existence of a deep gas accumulation can only be proven unequivocally by drilling wells outside conventional closure.Exploration for deep basin-type accumulations should focus on depositional-structural-diagenetic sweet spots (DSDS), irrespective of conventional closure. This is of particular significance for a potential Nappamerri Trough deep basin accumulation because depositional models suggest that the best net/gross may be in structural lows, inherited from syndepositional lows, that host stacked channel sands within channel belt systems. Limiting exploration to conventionally-trapped gas may preclude intersection with such sweet spots.


2020 ◽  
Author(s):  
Keith Stakes ◽  
◽  
Keith Stakes ◽  
Julie Bryant ◽  
Nick Dow ◽  
...  

The majority of the existing full-scale fire service research studied the impact of tactics on the residential fireground, specifically in single-family structures. This study builds upon prior research by conducting thirteen experiments in three-story, multi-family dwellings to quantify the impact of coordination between ventilation and suppression actions. Experiments were conducted in four, garden-style apartment buildings; each of which had two lower-level units, four first-floor units, and four second-floor units. The apartments shared a common stairwell that was enclosed for all of the experiments in this study. To examine the effectiveness of tactics in the fire apartment, common stairwell and applicable exposure apartments, four experiments were conducted in lower-level apartments, seven were conducted in first-floor apartments, and two were conducted in second-floor apartments including both bedroom and kitchen/living room fires. The fire size varied based on the amount of initial ventilation provided. The main control variables included the location of initial water application, the ventilation method, and the timing of ventilation relative to water application. The suppression tactics included interior water application, exterior water application followed by interior water application, and a combined interior and exterior water application. The ventilation tactics examined in these experiments included horizontal, vertical, positive pressure, and hydraulic ventilation. Similar to previous experiments in acquired single-family structures, there was no meaningful increase in temperature outside of fire rooms when ventilation tactics were executed in close coordination with (shortly after or shortly before) the onset of suppression. In contrast, for experiments where ventilation occurred with delayed suppression, temperature exposures increased throughout the fire apartment, and in experiments where the apartment door was left open, temperatures and carbon monoxide exposures increased throughout the common stairwell. Suppression actions, whether interior or exterior, resulted in a decrease in temperatures and gas concentrations at locations where occupants may potentially be located. The enclosed common stairwell, a unique feature of this experimental series, acted as capture of combustion products. Opening the apartment door to gain access should be thought of as an important ventilation action, both in terms of its potential to cause fire growth and its potential for smoke movement into the stairwell, limiting the egress for potentially trapped occupants in exposure units. Tactics such as door control, positive pressure ventilation, and hydraulic ventilation which were used both simultaneous with and sequentially post-suppression were shown to limit gas flows into the stairwell. After effective suppression, structure ventilation operations should similarly be cognizant of gas flows, with the aim of establishing flow throughout all areas where occupants may be located.


2021 ◽  
Author(s):  
Denis Sergeevich Nikolaev ◽  
Nazika Moeininia ◽  
Holger Ott ◽  
Hagen Bueltemeier

Abstract Underground bio-methanation is a promising technology for large-scale renewable energy storage. Additionally, it enables the recycling of CO2 via the generation of "renewable methane" in porous reservoirs using in-situ microbes as bio-catalysts. Potential candidate reservoirs are depleted gas fields or even abandoned gas storages, providing enormous storage capacity to balance seasonal energy supply and demand fluctuations. This paper discusses the underlying bio-methanation process as part of the ongoing research project "Bio-UGS – Biological conversion of carbon dioxide and hydrogen to methane," funded by the German Federal Ministry of Education and Research (BMBF). First, the hydrodynamic processes are assessed, and a review of the related microbial processes is provided. Then, based on exemplary field-scale simulations, the bio-reactive transport process and its consequences for operation are evaluated. The hydrogen conversion process was investigated by numerical simulations on field scale. For this, a two-phase multi-component bio-reactive transport model was implemented by (Hagemann 2018) in the open-source DuMux (Flemisch et al. 2011) simulation toolkit for porous media flow. The underlying processes include the transport of reactants and products, consumption of specific components, and the related growth and decay of the microbial population, resulting in a bio-reactive transport model. The microbial kinetic parameters of methanogenic reactions are taken from the available literature. The simulation study covers different scenarios on conceptional field-scale models, studying the impact of well placement, injection rates, and gas compositions. Due to a significant sensitivity of the simulation results to the bio-conversion kinetics, the field-specific conversion rates must be obtained. Thus, the Bio-UGS project is accompanied by laboratory experiments out of the frame of this paper. Other parameters are rather a matter of design; in the present case of depleted gas fields, those parameters are coupled and can be chosen to convert fully hydrogen and carbon dioxide to methane. Especially the well spacing can be considered the main design parameter in the likely case of a given injection rate and gas composition. This study extends the application of the previously developed code from a homogeneous-2D to the heterogeneous-3D case. The simulations mimic the co-injection of carbon dioxide and hydrogen from a 40 MW electrolysis.


2015 ◽  
Author(s):  
R.N.. N. Naidu ◽  
E.A.. A. Guevara ◽  
A.J.. J. Twynam ◽  
J.. Rueda ◽  
W.. Dawson ◽  
...  

Abstract Hydraulic fracturing is a commonly used completion approach for extracting hydrocarbon resources from formations, particularly in those formations of very low permeability. As part of this process the use of Diagnostic Fracture Injection Tests (DFIT) can provide valuable information. When the measured pressures in such tests are outside the expected range for a given formation, a number of possibilities and questions will arise. Such considerations may include: What caused such inflated pressures? What is the in-situ stress state? Was there a mechanical or operational problem? Was the test procedure or the test equipment at fault? What else can explain the abnormal behaviour? While there may not be simple answers to all of these questions, such an experience can lead to a technically inaccurate conclusion based on inadequate analysis. A recently completed project faced just such a challenge, initially resulting in poor hydraulic fracturing efficiency and a requirement to understand the root causes. In support of this, a thorough analysis involving a multi-disciplinary review team from several technical areas, including petrophysics, rock/geo-mechanics, fluids testing/engineering, completions engineering, hydraulic fracture design and petroleum engineering, was undertaken. This paper describes the evolution of this study, the work performed, the results and conclusions from the analysis. The key factors involved in planning a successful DFIT are highlighted with a general template and a work process for future testing provided. The importance of appreciating the impact of the drilling and completion fluids composition, their properties and their compatibility with the formation fluids are addressed. The overall process and technical approach from this case study in tight gas fields, will have applicability across similar fields and the lessons learned could help unlock those reserves that are initially deemed technically or even commercially unattractive due to abnormal or unexpected behaviour measured during a DFIT operation.


1989 ◽  
Vol 29 (1) ◽  
pp. 366 ◽  
Author(s):  
R. Heath

The Cooper Basin is located in the northeastern corner of South Australia and in the southwestern part of Queensland. The basin constitutes an intracratonic depocentre of Permo- Triassic age. The Cooper Basin succession unconformably overlies Proterozoic basement as well as sediments and metasediments of the Cambro- Ordovician age. An unconformity separates in turn the Cooper succession from the overlying Jurassic- Cretaceous Eromanga Basin sediments.The Permo- Triassic succession comprises several cycles of fluvial sandstones, fluvio- deltaic coal measures and lacustrine shales. The coal measures contain abundant humic kerogen, comprising mainly inertinite and vitrinite with a small contribution of exinite. All hydrocarbon accumulations within the Cooper Basin are believed to have originated from these terrestrial source rocks.Exploration of the basin commenced in 1959 and, after several dry holes, the first commercial discovery of gas was made at Gidgealpa in 1963. To date, some 97 gas fields and 10 oil fields, containing recoverable reserves of 5 trillion cubic feet of gas and 300 million barrels recoverable natural gas liquids and oil, have been discovered in the Cooper Basin. Production is obtained from all sand- bearing units within the Cooper stratigraphic succession.The emphasis of exploration in the Cooper Basin is largely directed towards the assessment of four- way dip closures and three- way dip closures with fault control, but several stratigraphic prospects have been drilled. Furthermore, in the development phase of some gas fields a stratigraphic component of the hydrocarbon trapping mechanism has been recognised.Improvements in seismic acquisition and processing, combined with innovative thinking by the explorers, have facilitated the development of untested structural/stratigraphic plays with large reserves potential. Exploration for the four- and three- way dip closure plays in the Cooper Basin is now at a mature stage. However, reserves objectives are expected to continue to be met, with the expectation of a continuing high success rate.Selected new plays are expected to be tested within a continuing active exploration program as exploration for oil and gas in the Cooper Basin refines the search for the subtle trap.


1996 ◽  
Vol 36 (1) ◽  
pp. 104
Author(s):  
H.R.B. Wecker ◽  
V. Ziolkowski ◽  
G.D. Powis

Over the last two decades, minimal gas exploration was undertaken in the northeastern Cooper Basin. It was viewed the area held negligible gas potential due to the perceived absence of conventional anticlinal traps and the marginal reservoir quality of the Permian sandstones.With the award of permit ATP 549P to Mount Isa Mines Limited in mid-1993, available seismic and well data were reviewed to highlight potential fault-controlled traps in the region and to define areas likely to contain more favourable reservoir sandstones. A vibroseis seismic survey provided the initial prospects and leads inventory upon which the 1994 drilling program was based. Four prospects were tested resulting in three gas discoveries.Based on these encouraging results, an additional phase of seismic acquisition was completed to increase the prospect inventory. Thereafter, a five well program was undertaken. Whilst the two appraisal wells were successful, three wildcat wells failed due to ineffective trapping.A completion and testing program has been initiated to further evaluate the field discoveries.From an exploration viewpoint, the recognition of a consistently productive sandstone in the basal Toolachee Formation within a broad fairway across the eastern ATP 549P permit block was a significant result which has important implications for future activities. Within the fairway, gas flows varying from 0.4 MMcfd up to 6.0 MMcfd were measured on openhole tests. In addition, substantial gas volumes in low permeability sandstones within the Patchawarra Formation have been defined.These discoveries, coupled with the number of prospects and leads and the proposed gas pipeline to Mount Isa and to southeast Queensland markets, provide strong impetus to the continued evaluation of this northern extension of the Cooper Basin gas province.


2000 ◽  
Vol 40 (1) ◽  
pp. 393 ◽  
Author(s):  
S.C. Lang ◽  
J. Kassan ◽  
J.M. Benson ◽  
C.A. Grasso ◽  
L.C. Avenell

Reservoir characterisation in fluvial and fluvial- lacustrine delta successions is enhanced by the use of appropriate modern and ancient analogues to understand subsurface reservoir architecture and to help build appropriately scaled reservoir models. Two case studies of reservoir characterisation in the Cooper Basin are used to illustrate the value of analogues. Firstly the Late Permian Toolachee Formation crevasse splay reservoirs of the Cooper Basin, southwest Queensland are outlined, and analogues from the Ob River in Western Siberia illustrate the relative scale of crevasse splay deposits within avulsion belts in a cool-temperate peat-forming environment. The South Blackwater coal mine in the Permian Bowen Basin is used as an analogue to quantify the 3D geometry and reservoir architecture of crevasse splays and to highlight subsurface reservoir heterogeneity.Secondly, the Early Permian Epsilon Formation shallow water lacustrine delta reservoirs are outlined, and analogues from the extant geometry of the distributary channels and relict mouth bar deposits from the fluvial dominated Neales Delta in Lake Eyre are used to interpret flow rate decline trends and probable reservoir architecture. The subsurface Tertiary lacustrine deltaic complex of the Sirikit Field from the Phitsanulok Basin, central Thailand, is selected as an ancient analogue for the multistorey reservoirs developed within amalgamated mouth bar complexes intersected in the lower Epsilon Formation.


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