Distribution and Behaviour of Oil and Water in Mississippian Limestone Reservoirs, Southeastern Saskatchewan

1963 ◽  
Vol 2 (03) ◽  
pp. 122-132 ◽  
Author(s):  
Ralph W. Edie
Keyword(s):  
Mississippian Limestone

scholarly journals Stratigraphic architecture of the Mississippian limestone through integrated electrofacies classification, Hardtner field area, Kansas and Oklahoma

2018 ◽  
Vol 6 (4) ◽  
pp. T1095-T1115 ◽  
Author(s):  
Niles W. Wethington ◽  
Matthew J. Pranter
Keyword(s):  
Nearest Neighbor ◽  
Depositional Environments ◽  
Significant Heterogeneity ◽  
High Porosity ◽  
Reservoir Properties ◽  
Subaerial Exposure ◽  
Stratigraphic Framework ◽  
Complex Structural ◽  
Mississippian Limestone ◽  
Field Area

The Mississippian Limestone formed through complex structural, stratigraphic, and diagenetic processes involving subsidence, tectonic uplift leading to periodic subaerial exposure, changes in ocean chemistry, variability inherent with carbonate cyclicity, as well as postdepositional alteration. These geologic complexities led to significant heterogeneity and compartmentalization within Mississippian mid-continent reservoirs, obscuring stratigraphic relationships. A novel log-based approach, called derivative trend analysis (DTA), is used to identify and correlate depositional cycles associated with five major stratigraphic zones. In the absence of abundant and complete core data, DTA serves as a rudimentary, yet informative, tool to effectively develop a sequence-stratigraphic framework. Classifying electrofacies, especially those constrained to core observations, can elucidate key relationships between depositional environments and reservoir properties, as well as provide an improved understanding of spatial heterogeneity. Three methods of electrofacies classification (artificial neural network, [Formula: see text]-means clustering, and [Formula: see text] nearest neighbor clustering) provide varying accuracies when used to create predictive lithology logs based only on the combined signatures of open-hole well logs in noncored wells. Stratigraphic models produced from the integration of these lithology logs with an interpreted stratigraphic framework reveal a relatively uniform, flat-lying basal Kinderhookian section, overlain by prograding clinoforms with internally shoaling-upward cycles of limestone, shales, and spiculites deposited during the Osagean and Meramecian stages. The sequence is capped by a high-porosity unit comprised mostly of brecciated chert associated with subaerially exposed strata underlying the sub-Pennsylvanian unconformity. Toward the south and east of the Hardtner field area, Osagean strata thin significantly and are covered by Meramecian spiculites of the Cowley Formation. Spatial porosity distributions reveal high reservoir quality deposits associated with regressive phases of third-order cycles, with the highest porosity intervals occurring up-section and toward the northeast of Hardtner field.

THE REFRACTION SEISMOGRAPH IN THE ALBERTA FOOTHILLS

Geophysics ◽  
1956 ◽  
Vol 21 (3) ◽  
pp. 828-838 ◽  
Author(s):  
G. J. Blundun
Keyword(s):  
Operating Conditions ◽  
Radio Communication ◽  
Interval Velocity ◽  
Mississippian Limestone ◽  
Interval Velocities ◽  
Definition Of ◽  
Characteristic Interval ◽  
Consequent Improvement ◽  
Continuous Determination

In the Alberta foothills the most valuable use of the refraction seismograph is for the definition of overthrust faulting in the Mississippian limestone which is overlain by a faulted, overthrust, and overturned Cretaceous section. Normally, two refracted arrivals are recorded with characteristic interval velocities of 14,000 ft/sec and 21,000 ft/sec, the former arising from an unknown Cretaceous marker, and the latter from the Mississippian. In contrast to a shot‐range of 65,000 ft required to record the refracted arrival from the Mississippian at a depth of 10,000 ft as the first event, a range of 20,000 ft permits recording it as the later event, with consequent improvement in the quality and reliability of the data, reduces the amount of surveying required together with smaller dynamite charges, and improves radio communication. A geophone spread of 6,300 ft with single geophones at 300 ft intervals recorded on 22 traces is recommended. Both in‐line and broadside refraction with the Mississippian arrival recorded as the later event have been used successfully with certain advantages to each method. The former permits continuous determination of the interval velocity of the refracted events as well as providing two‐way control; the latter is considerably faster, and often faulting may be observed directly on the seismograms without reduction of the data. Specimen seismograms are included to illustrate the two methods. Field operating conditions pertaining to survey tolerances, shot formation, size of dynamite charges, the weathering shot as a polarity check, filtering, geophone frequency, and costs are discussed.

Bituminous coals on emergent surfaces in an Asbian, lower Carboniferous (Mississippian) limestone succession on the North Wales carbonate platform, UK, and implications for palaeoclimate

2021 ◽  
pp. pygs2020-006
Author(s):  
Peter del Strother ◽  
Andrew Giże ◽  
Cathy Hollis ◽  
Duncan McLean
Keyword(s):  
Carbonate Platform ◽  
Local Development ◽  
Vitrinite Reflectance ◽  
Terrestrial Organic Matter ◽  
The North ◽  
North Wales ◽  
Bituminous Coals ◽  
Coal Petrology ◽  
Mississippian Limestone ◽  
Peat Formation

Emergent surfaces in the Mississippian (Asbian to Brigantian) carbonate platform succession of North Wales record periods of plant colonisation and peat formation that led ultimately to the local development of coals. Examination of bituminous coals on three emergent surfaces within Cefn Mawr Quarry reveals information on palaeoclimate that is not available from study of the limestones alone. Three coal seams in the Asbian Loggerheads Limestone Formation were identified and the lowest one studied in detail. Vitrinite reflectance data from alternating bands of vitrite and duroclarite microlithotypes, the distribution of pyrite within them, and the sharp contacts between them, suggest that there were abrupt changes in marine influence during the development of the peats that formed the coals. It is inferred that local palaeoclimate alternated between periods of high and low rainfall, the amount of rainfall influencing the extent to which seawater encroached into the peats, with higher rainfall suppressing the ingress of saline waters into groundwater. On the basis of modern peat growth rates, the timescale of the alternation indicated by each duroclarite-vitrite couplet is suggestive of an annual cycle, such as would arise in a monsoonal climate. The low proportion of ash in the three coals, the preservation of internal lamination, the low diversity of spore species in the lowest coal compared with the over- and underlying mudrock, and the presence of rhizoconcretions in palaeokarstic limestone beneath the lowest and highest coals, demonstrate that the peat swamps were isolated from the hinterland and autochthonous. This study demonstrates that a wider application of palynology and coal petrology is an important contribution to the study of marine carbonate successions of any age where terrestrial organic matter, formed during emergence, has been preserved.

BACTERIA CAN PENETRATE ROCK

1966 ◽  
Vol 12 (3) ◽  
pp. 477-484 ◽  
Author(s):  
G. E. Myers ◽  
R. G. L. McCready
Keyword(s):  
Atmospheric Pressure ◽  
Radioactive Phosphorus ◽  
Early Devonian ◽  
Late Mesozoic ◽  
The Core ◽  
Demineralized Water ◽  
Test Microorganism ◽  
Rock Cores ◽  
Mississippian Limestone ◽  
And Migration

A method is described for studying the penetration of bacteria in intact rock cores. The test microorganism (Serratia marcescens ATCC No. 274) was labelled with radioactive phosphorus (32P) and suspended in sterile demineralized water. The cell suspension was allowed to enter the epoxy-coated rock core under atmospheric pressure. Penetration and migration of the labelled microorganisms were followed by measuring the radiation emitted at ports drilled through the epoxy coating, at various locations throughout the length of the core, and at various intervals of time after the beginning of the experiment. When migration was considered to be complete the core was aseptically split longitudinally and the results of the radiation studies confirmed by autoradiogram and culture. S. marcescens passed through 14.25 in. of Berea sandstone (the longest core available), and through 3-in. cores (longest available) of Mississippian limestone, Early Devonian limestone, and Late Mesozoic sandstone. The significance of these findings is discussed with respect to presence of so-called prehistoric microorganisms in geological specimens.

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