Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-69).

No description available.

Measuring transport properties of rock samples under stress is essential to understanding and predicting the migration of fluids within the Earth's crust. Mudrocks play an essential role in petroleum systems as they are often the source rock and may act as a seal due to their low permeability. With increasing production from unconventional reservoirs where the mudrock is source, reservoir and seal, there is now even greater demand to understand the permeability and storativity of mudstones and tight sandstones. When hydraulic fracture treatment is used to enhance production, flow of hydrocarbons into the fractures will be ultimately controlled by the matrix permeability. Knowledge of the fluid transport properties of mudstones is currently hindered by a scarcity of published experimental data. In this thesis, a combination of permeability and ultrasonic velocity measurements allied with image analysis is used to distinguish the primary microstructural controls on effective stress dependent permeability. Permeabilities of cylindrical samples of Whitby Mudstone and Eagle Ford Shale have been measured using the oscillating pore pressure method at confining pressures ranging between 30-95 MPa and pore pressures ranging between 1-80 MPa. The results show that samples must be pressure cycled in order to obtain a reproducible behaviour, after which the relationship between permeability and effective stress can be described by an exponential law. The permeability of the Whitby Mudstone samples ranges between 7 ×10-21 m2 and 2 ×10-19 m2 (7 nd to 188 nd) and decreases by ~1 order of magnitude across the applied effective stress range. The permeability of the Eagle Ford Shale samples is slightly higher ranging between 2 ×10-18 m2 and 42 ×10-18 m2 (2 μd to 42 μd) and decreases by half an order of magnitude across the applied effective stress range. Permeability is shown to be more sensitive to changes in pore pressure than changes in confining pressure yielding values of alpha between 1.1-2.1 for Whitby Mudstone and 1.6-4.6 for Eagle Ford Shale. Gas slippage (Klinkenberg) effects are restricted to pore pressures below 10 MPa in the Whitby Mudstone and therefore do not affect the results presented. The permeability-effective stress relationship is thus empirically described using a modified effective stress law in terms of confining pressure, pore pressure and a Klinkenberg effect. Use of a simple reservoir model demonstrates that if pressure dependent permeability is not taken into account, substantial overestimation of gas flow rate and original gas in place will be made from well tests. Changes in ultrasonic velocity and pore volume were related to the observed loss of permeability with increasing effective stress, providing further insight into the nature of the permeability-controlling pore network. Combining the petrophysical data with pore conductivity modelling and microstructural analysis shows that at low effective stresses, permeability is controlled by a network of long, thin crack-like pores associated with grain boundaries. At high effective stresses, these cracks are closed and fluid is restricted to flowing through a less permeable network of higher aspect ratio, stiffer, nm-scale pores in the clay matrix. Applying the methods developed in the present work to different mudstones with a range of compositions and textures will help to refine understanding of the variability in fluid-conducting pore networks, thereby advancing the interpretation of data from well logs and well tests used for reservoir evaluation.

Hydrocarbon exploration involves drilling into or near salt deposits in the Gulf of Mexico, Brazil, Egypt, and the Middle East. Drilling these systems has proven to be quite dangerous, challenging, and expensive due to the pressure and stress perturbations that exist around the salt. My study focuses on characterizing the pressure and stress distribution at the Mad Dog field, which is a large oil field below an allochthonous salt body in the deepwater Gulf of Mexico. The Mad Dog field lies beneath the Sigsbee Escarpment, which represents the surface and seaward-most indicator of a mobile salt in Green Canyon blocks 781, 782, 825, and 826, 190 miles southwest of New Orleans in 4,500-6,500 feet of water. I characterize the pressure distribution within the Lower Miocene sandstone reservoir which has produced over 100 million barrels to date. I map the reservoir horizon using 3D seismic data and that the reservoir is a complex regional anticlinal structure that is separated by numerous normal faults that cause it to be segmented into compartments. The in-situ pore pressures show that the compartments are not in pressure communication across the field and that multiple aquifer phase pressures are present. The in-situ pore pressure measurements are used to characterize the pressure distribution in the Miocene sediments below the salt body and in front of the mobile salt body. These measurements show that between the upper Miocene to middle Miocene there is an absolute pressure decrease and between the middle to lower Miocene there is a large pressure increase. This pressure distribution is seen both within the Miocene sediments below salt and in front of salt. A porosity and effective stress relationship from shallow Pleistocene sediments was developed to predict the pressure behavior observed within the Miocene and compare the predicted pressure with in-situ pore pressure measurements. The mudstone pressure prediction overestimates the in-situ sand pore pressure. The mudstones bounding regional sandstone have a constant porosity throughout the field, suggesting that the vertical effective stress is constant. These observations can be used to estimate the mudstone pore pressure in a new well location. If the vertical effective stress in an offset well is known and given knowledge of the total vertical stress in the new well location, the mudstone pore pressure can be estimated. / text

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17875号 / 工博第3784号 / 新制||工||1579(附属図書館) / 30695 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 松岡 俊文, 教授 大津 宏康, 准教授 村田 澄彦 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Abstract not available

Understanding thickness variation and facies transitions in the mudstone-rich part of the Upper Middle Jurassic (Callovian) Entrada Sandstone depositional system is critical for constraining the paleogeography and evaluating the economic potential of Utah's Entrada Sandstone. Facies of the Entrada Sandstone in south-central Utah are dominated by mudstone-rich intertidal facies that were widespread within the Jurassic seaway. Intertidal deposits interfinger basinward with subtidal ooid-bearing shoals and bars, and landward supratidal sabkha, and erg-margin eolian deposits. Three sections were measured to improve understanding of the lateral and vertical facies transitions. Variations in thickness indicate the rate of developing accommodation space was high along the southwestern shoreline and relatively low along the northeastern shoreline during Callovian time. Although accommodation space was highest in the west, sediment supply from the west kept pace with, and eventually outpaced subsidence. In the east, sediment supply was significant but at one time was outpaced by subsidence, creating a complete range of facies, from subtidal to supratidal deposits. Along this eastern shoreline, erg-margin coastal dunes associated with the larger erg to the east eventually prograded westward. The variation in subsidence, sediment supply, and sediment source makes sequence stratigraphic correlation difficult. Reservoir-quality sandstones are associated with muddy sections of the Entrada Sandstone within the San Rafael Swell. Porosity and permeability of the facies in this area indicate excellent reservoir potential in three of eight facies that were studied. Porosities of these potential reservoirs ranged from 11-22%, with permeabilities ranging from 44-430md. These high quality reservoir facies are surrounded by muddy, low reservoir-quality rocks, creating conditions amenable to the development of stratigraphic hydrocarbon traps. Based on further study and a modern analog at the north of the Gulf of California, Hicks and others' (2010) depositional model for the Entrada Sandstone of south-central Utah has been modified to include newly interpreted facies. This improved depositional model may have predictive power in exploring for stratigraphic and combination traps within the Entrada system of Utah and analogous depositional systems throughout the world.

The Yazoo Clay is a calcareous fossiliferous mudrock that outcrops in a northwest-southeast belt across much of Mississippi and in adjacent states. Based on over 240 X-ray diffraction analyses, the average composition of the Yazoo Clay is 28% smectite, 24% kaolinite, 22% quartz, 15% calcite, 8% illite, 2% feldspar, and 1% gypsum. Exposed Yazoo clay is weathered to a depth of 30-40 ft. and has a distinctive yellow/brown color; unweathered Yazoo is blue/gray. In most wells, smectite is more abundant in weathered clay than in unweathered clay. Mineralogic changes correlate well with engineering properties of the samples, which in general show a decrease in plasticity indices with depth. Weathered Yazoo clay exhibits greater mineralogic variability than unweathered clay. Mineralogical content also varies laterally. Lateral variation, along with correlative smectite content and engineering properties, is the reason for ?roller coaster? roadways and structural damage caused by the swelling Yazoo Clay.

Hyaloclastic sediment forms an identifiable stratigraphic interval within the Troutdale Formation that can be traced from the Bridal Veil channel to the Portland basin. Hyaloclastic sediment composed chiefly vitric sands is found interbedded with muds, sandy muds and gravels penetrated by wells in northeast Portland are correlated with the upper member of the Troutdale Formation. These beds are characteristic of the informal upper member of the Troutdale Formation in the Bridal Veil channel of the ancestral Columbia River (Tolan and Beeson, 1984) and the type area of the Troutdale Formation exposed along the Sandy River (Trimble, 1963). Fluvially deposited hyaloclastic beds within the upper Troutdale Formation are interpreted to be the result of interaction of Cascadian basaltic lavas with an ancestral Columbia River (Tolan and Beeson, 1984; Trimble, 1963). Glass clasts taken from well and outcrop samples have nearly identical trace and minor element geochemical content as determined by instrumental neutron activation analysis.

Indiana University-Purdue University Indianapolis (IUPUI) / The shale and mudstone directly superjacent to Desmoinesian coal seams of southern Indiana (Springfield, Houchin Creek, Survant, and Seelyville coals) were initially deposited under marine waters and are shown to exhibit high concentrations of organic carbon, sulfur and redox-sensitive metals (Mo, V, Ni, Fe, and U) that were sequestered during times of benthic anoxia and intermittent to sustained euxinia (anoxic and sulfidic). Strata upsection display geochemical signatures that indicate increasingly oxic and nearshore sedimentation that mirrors cyclothemic sequence stratigraphic trends Carbon source, nearshore and offshore proximity, freshwater and marine influence, and redox conditions of the epeiric sea overlying southern Indiana during the Late Middle Pennsylvanian were identified and tracked throughout the deposition of four drill cores of the Petersburg, Linton and Staunton Formations. Carbon, nitrogen, and sulfur data (total organic carbon [TOC], total nitrogen [TN], and total sulfur [TS]); paleoredox proxies ([Mo/Al], [V/Al], [Th/U], [Fetot/Al]); organic carbon isotopes (δ13Corg); and detrital influx concentrations (Zr) were all used in conjunction with lithological and paleontological interpretations to better understand the mode of deposition in this unique midcontinent ancient epeiric sea. Geochemical results when combined with lithologic and paleontologic interpretations reveal a dynamic environmental system where water column geochemistry varies with the influence of variable magnitudes of epeiric seawater flooding on the extensive peatlands of equatorial Late Middle Pennsylvanian southern Indiana.