The Upper Triassic Chang-7 Member of the Ordos Basin contains typical tight sandstone reservoirs. Reservoir quality is affected by diagenesis, which a critical factor in oil exploration. In this study, sandstones were studied variety experimental methods, including thin sections, scanning electron microscopy (SEM), and X-ray diffraction (XRD), to determine reservoir characteristics diagenesis d...

Abst rac t -Oxygen isotopic compositions were determined for coexisting mixed-layer serpentine-chlorite (Sp-Ch) and illite-smectite (I-S) from 5 Tuscaloosa Formation sandstone cores sampled between 1937 and 5470 m burial depth. High gradient magnetic separation (HGMS) was used to concentrate Sp-Ch and I-S from the <0.5 p~m fraction of each core sample into fractions with a range in the Sp-Ch : ...

Elephants are currently the largest terrestrial mammals, along with their extinct ancestor mammoth. These species of great interest due to geographic distribution and ecological importance. However, bone mineral characteristics skeleton as well alteration during burial processes over millions years have been poorly investigated. In current research, we analyzed compositional structural properti...

[1] In clay-rich sediment, microstructures and macrostructures influence how sediments deform when under stress. When lithology is fairly constant, anisotropy of magnetic susceptibility (AMS) can be a simple technique for measuring the relative consolidation state of sediment, which reflects the sediment burial history. AMS can reveal areas of high water content and apparent overconsolidation a...

Reconstructing provenance in sandstones can be challenging, especially when the hinterland palaeogeology is unknown due to burial, diagenesis or weathering of original outcrops. As sedimentary processes alter distribution minerals depositional environment, use multiple methods reduces uncertainties, because, together, they account for depositionally-controlled textural and mineralogical re-dist...

Prehistoric cave sediments are often subjected to severe mechanical and chemical alteration, making it difficult to interpret aspects of their archaeology. Theopetra cave offers unique opportunities to resolve aspects of this problem, particularly in relation to chemical changes, because it has a relatively well defined stratigraphy and its older deposits have been subjected to unusually severe...

Oilfield Review Summer 2010: 22, no. 2. Copyright © 2010 Schlumberger. For help in preparation of this article, thanks to Neil Hurley, Dhahran, Saudi Arabia; and L. Bruce Railsback, The University of Georgia, Athens, USA. The early search for oil and gas reservoirs centered on acquiring an overall view of regional tectonics, followed by a more detailed appraisal of local structure and stratigra...

We simulate the effects of diagenesis, cementation and compaction on elastic properties shales sandstones with four different petro-elastical theories a basin-evolution model, based constant heating sedimentation rates. consider composed clay minerals, mainly smectite illite, depending burial depth, pore space is assumed to be saturated water at hydrostatic conditions. Diagenesis in shale (smec...

The information potentially available from biomolecules is vast, and often related to the most central concerns of archaeology. It is, however, entirely limited by the survival of such complex molecules and, further, by the sensitivity of the methods for their recovery and analysis. Recent advances in immunology, in protein chemistry and especially in the amplification of DNA sequences are begi...