<p> Despite an increased interest in exploitation of hydrocarbon source rock resource plays, there remains an incomplete understanding of organic and inorganic component interaction within source rocks. Few studies have been conducted concerning the associations between organic and inorganic geochemistry for the purposes of understanding kerogen type, thermal maturity influence, and paleoredox setting. This investigation&rsquo;s goal was evaluating these relationships with samples from the Eagle Ford Formation using organic data, obtained by Rock-Eval pyrolysis and oxidation, and inorganic data, obtained using high-temperature and pressure leaching experiments. The study additionally tested various parameters for whole rock batch leaching, including time, temperature of leaching, and use of acids. The most successful leaching technique was applied to samples that (1) had first been subjected to Rock-Eval pyrolysis, at three different maximum temperatures (450&deg;C, 550&deg;C, and 650&deg;C), as well as (2) samples that had not been subjected to pyrolysis. As different kerogen fractions were destroyed at these different temperatures, variances in elemental concentrations leached from these samples could be attributed, at least partially, to these fractions. Using this approach, the lower molecular weight kerogen fraction contained most of the elements likely attributable to carbonates and sulfides associated with the kerogen (e.g., Ca, Mg, Mn, Mo, P, S, Sr, Zn). The higher molecular weight portion contained more elements probably attributable to clays, quartz, and other clastic minerals (e.g., Al, Fe, K, Si). An evaluation of the overall element chemistry of the rock paired with Rock-Eval parameters showed (1) major/trace elements varied according to amount and type of organic carbon in the Eagle Ford samples, (2) relative abundances of certain major/trace elements were useful proxies for bulk mineralogy and depositional environment, and (3) relationships between certain clay-related major and trace elements and T_max values suggesting clays and trace elements acted to catalyze the cracking of the kerogen.</p>

<p> The fluvial and deltaic Wilcox Group is a major target for hydrocarbon and coal exploration in northern and central Louisiana. However, the characterization and delineation of fluvial systems is a difficult task due to the variability and complexity of fluvial systems and their internal heterogeneities. </p><p> Seismic geomorphology is studied by recognizing paleogeographic features in seismic stratal slices, which are seismic images of paleo-depositional surfaces. Seismic attributes, which are extracted along seismic stratal slices, can reveal information that is not readily apparent in raw seismic data. The existence and distribution of fluvial channels are recognized by the channel geomorphology in seismic attributes displayed on stratal slices. The lithologies in the channels are indicated by those seismic attributes that are directly related to the physical properties of rocks. Selected attributes utilized herein include similarity, spectral decomposition, sweetness, relative acoustic impedance, root mean square (RMS) amplitude, and curvature. Co-rendering and Red/Green/Blue (RGB) display techniques are also included to better illuminate the channel geometry and lithology distribution. Hydrocarbons may exist in the channel sand-bodies, but are not explicitly identified herein. Future drilling plans for oil and gas exploration may benefit from the identification of the channels and the lithologies that fill them.</p>

<p> Compositional analysis of reservoir rock is a vital aspect of oil exploration and production activities. In a broad sense, knowing the mineral composition of a reservoir can help with characterization and interpretation of depositional environments. On a smaller scale, identifying mineralogy helps calibrate well logs, identify formations, design drilling and completion programs, and screen for intervals with potential problem minerals, such as swelling clays. The petroleum industry utilizes two main methods to find compositional mineralogy, x-ray diffraction (XRD) and thin section analysis. Both methods are time consuming, expensive, and destructive. An alternative method for compositional analysis that includes quantitative mineralogy is a valuable prospect, especially if it had the potential to characterize the total organic content (TOC). </p><p> The remote sensing community has been using infrared spectroscopy to analyze mineralogy for years. Within the last ten years, the advancement of infrared spectrometers and processing programs have allowed infrared spectra to be taken and analyzed faster and easier than before. The objective of this study is to apply techniques used in remote sensing for quantitatively finding mineralogy to the petroleum industry. While developing a new methodology to compositionally analyze reservoir rock, a database of infrared spectra of relevant minerals has been compiled. This database was used to unmix spectra using a constrained linear least-squares algorithm that is used in the remote sensing community. A core has been scanned using a hand-held infrared spectrometer. Results of the best method show RMS error from mineral abundance to be under five percent.</p>

No description available.

<p> Two hydrothermal experiments were performed using sandstone core material from the Norwegian North Sea with synthetic brines reacted at approximately 150&deg;C and 450 bars, temperature and pressure calculated to simulate a depth of burial of approximately 4 km. The results of the experiments were analyzed with geochemical modeling and with chemical and petrographic analyses. Geochemical modeling with several computer programs indicated that the experimental fluid was undersaturated with respect to K-feldspar, kaolinite, and illite, but supersaturated with respect to muscovite. Chemical analysis with inductively-coupled plasma mass spectrometry indicated that the fluid reached saturation with respect to K-feldspar. Petrographic analysis with scanning electron microscopy and energy-dispersive scanning indicated that changes took place over the course of the experiments in both the clay and non-clay mineral fractions, and this result was verified by X-ray diffraction analysis that indicated dissolution of both K-feldspar and illite and formation of muscovite. These converging lines of evidence indicate that significant changes took place in the clay mineral fraction of the experimental sandstone core material, reacted at realistic basin temperature, pressure and geochemical conditions, over the course of several weeks.</p>

<p> Located in LaSalle Parish, Louisiana, the area of interest for this study encompasses portions of the Tullos-Urania and Olla oil fields, with their hydrocarbon accumulation stemming from the Wilcox Group. The overall objective of this study is threefold; first, generate structure maps of the strata within this area of investigation and identify the productive formations. Second, utilize seismic modeling from local wells defining the most accurate resistivity-to-sonic transform. The last goal is to generate an accurate seismic-to-well tie employing the most accurate sonic log generated at the wells bounding the high-resolution shallow imaging seismic data. This study must use resistivity data to model sonic logs for the bounding wells which have no sonic logs available. The modeled sonic logs are then used to create time- depth relationships between the acquired seismic data and the wells bounding the seismic line. To use resistivity logs to model a sonic log, this study will compare three equations (Faust, 1953; Kim, 1964; Smiths, 1968) to determine their relative accuracies for a one-step resistivity-to-sonic transform. Accuracy is measured by the absolute average deviation of the modelled sonic data from the measured sonic data from wells within the study area, but distant from the seismic line, which have recorded sonic logs. The results of this study indicate that the one-step resistivity-to- sonic equation proposed by Faust (1953) generates the least amount of error when applied to the short resistivity curve. Throughout the modeled logs, the Faust (1953) equation generates an absolute average deviation of 6.0% for the short resistivity curves while Kim&rsquo;s (1964) and Smiths (1968) equations produce 9.7% and 12.8% absolute average deviation. By understanding the variability of these models, future studies can ascertain the best fit model for further investigation of shallow hydrocarbon bearing formations within, or similar to, the Paleocene-Eocene aged strata in Central Louisiana.</p><p>

<p>Prolific amounts of oil and gas have been produced from the San Joaquin Basin in many different oil and gas fields. In many cases, the petroleum system is easily identifiable, and the path hydrocarbons take from source area to trap are known. This study aims to identify secondary migration pathways of hydrocarbons from the source to the trap in an oil field near Fresno, California, where the source is about 35 miles from the trap. To create an accurate subsurface interpretation of the study area, 3D seismic data and more than 300 well logs were used. From subsurface structure maps, net sand maps, an Allan profile, and regional research, it was found that there are two possible migration scenarios that reasonably describe the secondary migration of hydrocarbons into the study area. Six normal faults within the field play large roles as seals and/or migration pathways, and to better understand hydrocarbon migration in the study area, further work must be done on the sealing/leaking behavior of the faults within the field.

<p>The Denver-Julesburg Basin (DJ Basin) has been a productive oil and gas field since 1970 where operators began targeting the J sandstone (Sonnenberg 2013). Within the DJ Basin, the Wattenberg field has been the ?hot spot? for the past several years due to its high gas to oil ratio. The Niobrara Formation has added new value to this area as the use of horizontal drilling and hydraulic fracturing has become common practice for operators in the Wattenberg since 2009 (Sonnenberg 2013). This formation is a ?tight? rock that has very little connectivity making the hydraulic fracturing technique a necessity for economical wells. There are a large number of faults seen in the Wattenberg field that can have just a few feet of displacement to very large faults with 100+ feet of displacement. These faults are likely part of a polygonal fault system that has been linked to dewatering events that occurred prelithification in the Wattenberg Field (Underwood 2013). Along some of these major faults we see sections of Niobrara Formation that are missing, and these fault planes provide a pathway for the expulsion of this sediment. Understanding the pre-lithification faulting and missing section in the Niobrara Formation could result in added economic value as this could lead to finding optimal well placement for maximizing oil recovery. This study was driven by the hypothesis that the missing section of Niobrara Formation could be linked to the Pierre Shale?s Tepee Buttes. To determine the origin of the Tepee Buttes seismic data, well logs, thin sections, and XRF data was used to further investigate the Tepee Buttes, Niobrara Formation Chalks and Marls, Fort Hays Limestone, and Pierre Shale.

<p> Extreme heterogeneity in oil saturation between closely adjacent sandstone beds reflects different timing and degree of diagenesis. Understanding the distribution and origin of such heterogeneity is critical to effectively exploiting intercalated sandstone deposits within fine-grained unconventional reservoirs and in unraveling subtleties of stratigraphic traps. Sea cliff exposures at Point Fermin, California, expose a submarine channel facies within the largely hemipelagic facies. Separated by only meters, Point Fermin Sandstone is oil-saturated, whereas Altamira Shale sandstone is not. Samples were analyzed for porosity, permeability and fluid saturation in conjunction with thinsection petrographic analysis. Sandstones are primarily schist- bearing lithic arenites and the grains are cemented mostly by rhombic dolomite. Data show that both units have the same provenance but differ in the timing and type of diagenesis with shale-hosted sandstones generally showing earlier cementation. The degree and type of cementation occluded pore spaces to prevent hydrocarbon charging in the non-saturated sandstone.</p>

<p> The submarine-fan-dominated, proximal Los Angeles basin contains interstratified hemipelagic strata coeval with the widespread Miocene Monterey Formation that accumulated in other California margin basins. Although more detritalrich and containing greater abundance of plagioclase and muscovite than more distal, outboard basins, a four-part compositional zonation is recognized in the fine-grained facies, similar to the stratigraphic succession of the Santa Barbara coastal area. In ascending stratigraphic order, these include a basal interbedded calcareous-siliceous zone, a phosphatic zone, a calcareous-siliceous zone, and an uppermost siliceous zone. To establish these zonations, 125 samples from five wells in a north-south transect across the western basin from East and West Beverly Hills, Inglewood, and Wilmington oil fields were analyzed for bulk chemical composition by XRF and quantitative mineralogy by XRD and FTIR. The mineralogic composition of the fine-grained detrital fraction makes use of geochemical equations for sedimentary components developed elsewhere unsuitable to the Los Angeles basin.</p>