Delineating ground deformation over the Tengiz oil field, Kazakhstan, using the Intermittent SBAS (ISBAS) DInSAR algorithm

Changes in subsurface pore pressures and stresses due to the extraction of hydrocarbons often cause deformation over oil and gas fields. This can have significant consequences, including ground subsidence, induced seismicity and well failures. Geodynamic monitoring is an important requirement in recognising potential threats in sufficient time for remedial measures to be implemented. Differential interferometric synthetic aperture radar (DInSAR) is increasingly utilised for monitoring ground deformation over oil and gas reservoirs, achieving greater spatial coverage than traditional field-based surveying techniques. However, ground deformation over oil and gas fields can extend regionally into the surrounding rural landscape, where many conventional DInSAR techniques are of limited use due to the dynamic nature of the land cover. The Intermittent Small Baseline Subset (ISBAS) method is an advanced DInSAR technique, which considers the intermittent nature of coherence over dynamic land cover types to obtain markedly more ground motion measurements in non-urban regions. In this study, the ISBAS technique is used to delineate deformation over the super-giant Tengiz oil field in rural Kazakhstan. Analysis of ENVISAT data for 2004–2009 reveals a well-defined bowl subsiding with a maximum rate of −15.7 mm/year, corroborated by independent DInSAR studies and traditional levelling data. Subsequent application of ISBAS to Sentinel-1 data reveals significant evolution of deformation over the field in 2016–2017, with subsidence increasing dramatically to a maximum of -79.3 mm/year. The increased density of measurements obtained using the ISBAS technique enables accurate and comprehensive delineation and characterisation of ground deformation in this rural landscape, without the need for corner reflectors. This enhanced information could ultimately aid reservoir characterisation and management, and improve understanding of the risk posed by ground subsidence and fault reactivation

Investigation of changes in dem, constructed from time to time data from the seabed

The study of seabed relief is part of operations by development of the mineral deposits, which are in the territory of water objects. All of them are required at the stage of industrial planning, construction and exploration, definition of geo-hazard, for the monitoring activity and also required to repel potential threats, including natural ones, etc. The uniqueness of the ecosystem and bioresources of the Caspian Sea against the backdrop of unfolding offshore oil production, sharply raises the issue of monitoring and forecasting water level fluctuations. Annual bathymetric studies in the territory of the sites allow the analysis of changes in the shape of the seabed relief.The digital model of relief, which is used in geology, geomorphology, cartography and many other application-oriented directions, is result of such operations. Article questions of creation DEM of a bottom, types and methods of obtaining bathymetric data are considered. Under the digital model of the topography (DEM) of the bottom is understood the organized structure of files containing vector representations of spatial objects of different types, attributive information about them and topological relationships between them. The comparative analysis of creation of DEM with different cell sizes and interpolation types of a digital grids is presented. Recommendations are given on the choice of DEM depending on the targeted use of the resulting data

STRATEGIES OF GNSS PROCESSING AND MEASURING UNDER VARIOUS OPERATIONAL CONDITIONS

Purpose. GNSS technology is one of the key elements of maintenance of the mining works. Mostly, the GNSS observations in mining regions are accomplished under adverse surveying conditions. The presented paper is aimed at studying the problem of GNSS accuracy under various adverse operational conditions that may encounter during surveying works in deposit fields and downgrade the GNSS accuracy. Methodology. Despite the well-defined problem of GNSS accuracy, each year, new receiver models and software versions come into use, which in turn, needs a more profound analysis of their reliability, accuracy, and efficiency. This study provides relevant information about the static tests that were executed in the canopy, multipath, and open environments to assess the performance of the user segment from different manufacturers. The equipment of three manufactures was tested: Leica, Trimble, and Javad. The test results for two satellite systems, GPS and GLONASS, are presented. Findings. The obtained results can be generalized to the following outputs. Trimble performed the best on the canopy site in terms of position quality and fix solution. Javad had the best agreement for horizontal, height, and 3D solutions between dual and single frequency processing on the multipath site. On the open spot, Leica’s horizontal solution between dual and single frequency processing was the most consistent. It is challenging to state which receiver performed better in the vegetation cover. Originality. The study aims to develop a general procedure to estimate the accuracy of different GNSS processing strategies under different environments. Practical value. The given research has a strong hands-on background insofar as the principal stress is made on field measurements. The research results can be employed to refine the GNSS surveying workflow for open-pit mines

Comparison of digital elevation models generated with open source software from various satellite imagery

Manuscript is devoted to comparative analysis of digital elevation models (DEMs) derived from data collected on the city road interchange of the Almaty by different methods. Nowadays this is an actual theme for the Almaty city, as the growing metropolitan area. Specifically, there is a traffic flow increase every year, and therefore it is necessary to solve the problem of the city\u27s road load by building new city road interchanges with greater capacity, at the same time, and to increase efficiency of existing roads monitoring. It is also necessary to estimate time and financial expenses for realization of the future projects on construction of road interchanges and exploitation roads. Therefore, current paper is focused on the modern technology analysis and development of the high-performance methods for collecting and obtaining information about the terrain. This is important aspect of the decision making process. The purpose of described research is to comparison of the main processing techniques in open source and commercial software products by merging of remotely sensed data of different sources (satellite and laser scanning). Paper is culminated by discussion of the economic efficiency of geo database processing methods for city roads. Finally an assessment of results, described it this paper is a part of a study to evaluate DEMs. Recommendations are given on the choice of methods for obtaining a high resolution imagery DEM for the construction of city road interchange, as well as the factors that affect the qualitative construction of the DEM