Structural, petrophysical, and geological constraints in potential field inversion using the Tomofast-x v1.0 open-source code

The quantitative integration of geophysical measurements with data and information from other disciplines is becoming increasingly important in answering the challenges of undercover imaging and of the modelling of complex areas. We propose a review of the different techniques for the utilisation of structural, petrophysical, and geological information in single physics and joint inversion as implemented in the Tomofast-x open-source inversion platform. We detail the range of constraints that can be applied to the inversion of potential field data. The inversion examples we show illustrate a selection of scenarios using a realistic synthetic data set inspired by real-world geological measurements and petrophysical data from the Hamersley region (Western Australia). Using Tomofast-x's flexibility, we investigate inversions combining the utilisation of petrophysical, structural, and/or geological constraints while illustrating the utilisation of the L-curve principle to determine regularisation weights. Our results suggest that the utilisation of geological information to derive disjoint interval bound constraints is the most effective method to recover the true model. It is followed by model smoothness and smallness conditioned by geological uncertainty and cross-gradient minimisation.

Transformation of oil and gas fields based on information technologies

Currently, there is an opportunity to ensure digital transformation in the leading oil and gas companies in Russia. The main task of the transformation is to reduce capital and operating costs and increase production efficiency. The objects of transformation are processes, information, and people. Considering the existing technological and geological constraints for the Arctic fields, it is advisable to ensure the initial implementation of the principles of a digital intelligent field when creating control systems for wells and control production complexes. An important component is the development of an effective decision support system as a tool for calculating forecast tasks that provides strategic and tactical planning when modeling geological and technological processes online. The materials provide the structure of remote management of geographically distributed facilities of PJSC Gazprom, as well as solutions already implemented and confirmed the effectiveness of management for the Bovanenkovo oil and gas condensate field located in the Arctic on the Yamal Peninsula.

Risk Reduction on the Western Siberia Prospect Using Stochastic Seismic Inversion and Geological Constraints

Seismic data is a main source of information for lateral forecast of lithofacies. No one can deny that seismic data is a useful method to determinate structure of prospects. However, we have to accept to urgent need to implement steps that will make possible to predict distribution of lithofacies. In exploration, the prediction of lithology and fluid properties is a main goal. Popularity and comparative simplicity of inversion, made seismic inversion popular for reservoir characterization. Despite the benefits of method, inability to estimate uncertainty of models, stochastic seismic inversion was inveted. A stochastic seismic inversion combine relationship with varying lithofacies parameters and elastic properties using uncertainty of each data. Additional modification of stochastic seismic inversion is geological constraints allows to exclude not appropriate realization and obtain correct probability model of lithofacies. Comparison of approaches and results on a real set provided from the Tyumen formation in Western Siberia allows to estimate advantages and disadvantages of modification stochastic Seismic inversion.

High interstadial sea levels over the past 420ka from Huon terraces (Papua New Guinea)

The history of sea level across the Quaternary is essential for assessing past and future climate and geodynamics. Global sea-level reconstructions are typically derived from oxygen isotope curves, but require calibration with geological constraints that are particularly scarce prior to the last glacial cycle (>130 ka). The exceptionally well-preserved coral reef terrace sequence in the Huon Peninsula (Papua New Guinea) may provide such constraints up to ~420 ka, but has never been analysed in its full extent, or with high-resolution topographic data. Here we apply novel geometric approaches to show that the terrace sequence deformation pattern can be approximated by a northward tectonic tilt, and estimate relative sea-level (RSL) for 31 Late Pleistocene periods, including several periods for which no other RSL data exists elsewhere. Supported by reef modelling, these estimates suggest that global mean sea-level curves derived from oxygen isotopes systematically underestimate interstadial sea-level elevations, by up to ~20m. We propose that this discrepancy is either an effect of incorrect oxygen isotope curve calibrations, or that some short-lived sea-level variations are simply not recorded in oxygen isotope ratios.

Creating the funerary landscape of Eastern Sudan

Funerary landscapes are eminent results of the relationship between environments and superstructural human behavior, spanning over wide territories and growing over centuries. The comprehension of such cultural palimpsests needs substantial research efforts in the field of human ecology. The funerary landscape of the semi-arid region of Kassala (Eastern Sudan) represents a solid example. Therein, geoarchaeological surveys and the creation of a desk-based dataset of thousands of diachronic funerary monuments (from early tumuli up to modern Beja people islamic tombs) were achieved by means of fieldwork and remote sensing over an area of ∼4100 km2. The wealth of generated information was employed to decipher the spatial arrangement of sites and monuments using Point Pattern Analysis. The enormous number of monuments and their spatial distribution are here successfully explained using, for the first time in archaeology, the Neyman-Scott Cluster Process, hitherto designed for cosmology. Our study highlights the existence of a built funerary landscape with galaxy-like aggregations of monuments driven by multiple layers of societal behavior. We suggest that the distribution of monuments was controlled by a synthesis of opportunistic geological constraints and cultural superstructure, conditioned by the social memory of the Beja people who have inhabited the region for two thousand years and still cherish the ancient tombs as their own kin’s.

Earth’s carbon deficit caused by early loss through irreversible sublimation

Carbon is an essential element for life, but its behavior during Earth’s accretion is not well understood. Carbonaceous grains in meteoritic and cometary materials suggest that irreversible sublimation, and not condensation, governs carbon acquisition by terrestrial worlds. Through astronomical observations and modeling, we show that the sublimation front of carbon carriers in the solar nebula, or the soot line, moved inward quickly so that carbon-rich ingredients would be available for accretion at 1 astronomical unit after the first million years. On the other hand, geological constraints firmly establish a severe carbon deficit in Earth, requiring the destruction of inherited carbonaceous organics in the majority of its building blocks. The carbon-poor nature of Earth thus implies carbon loss in its precursor material through sublimation within the first million years.