The drilling-related geomechanics requires a better understanding of the encountered formation properties such as poroelastic parameters. This paper shows set of laboratory results of the dynamic Young’s modulus, Poisson’s ratio, and Biot’s coefficient for dry and water-saturated Istebna sandstone samples under a series of confining pressure conditions at two different temperatures. The predicted results from Wyllie’s equation were compared to the measured ones in order to show the effect of saturation on the rock weakening. A negative correlation has been identified between Poisson’s ratio, Biot’s coefficient and confining pressure, while a positive correlation between confining pressure and Young’s modulus. The predicted dynamic poroelastic rock properties using the P-wave value from Wyllie’s equation are different from measured ones. It shows the important influence of water saturation on rock strength, which is confirmed by unconfined compressive strength measurement. Linear equations have been fitted for the laboratory data and are useful for the analysis of coupled stress and pore pressure effects in geomechanical problems. Such results are useful for many drilling applications especially in evaluation of such cases as wellbore instability and many other drilling problems.

Понимание физико-механических свойств горных пород считается важным в бурении, геотехнике и строительстве. Осведомленность об этих параметрах породы помогает, например, избежать или минимизировать нестабильность зоны вокруг ствола скважины во время бурения. Лабораторный эксперимент по изучению этих параметров может быть выполнен двумя различными методами: статическим, когда образец разрушается после испытания, и динамическим, известным как неразрушающий метод. Неразрушающий метод с использованием ультразвуковых волн в серии различных условий напряжения, начиная с 7 до 56 МПа с шагом в 7 МПа, был использован для характеристики механических свойств сухого песчаника из Збилутова при 20 и 80 °C. Скорость первичных и вторичных волн в этих диапазонах была записана для определения изменения механических свойств. Результаты показали, что модуль Юнга, объемный модуль, модуль сдвига и постоянная Ламе песчаника из Збилутова имеют положительную корреляцию с хорошим коэффициентом и увеличенным напряжением, в то время как коэффициент Пуассона показал отрицательную корреляцию. Кроме того, влияние температуры на параметры породы подтверждается уменьшением скорости первичной волны в двух разных диапазонах температур. Такие результаты необходимы при подготовке бурового раствора соответствующей плотности для бурения, что влияет на нестабильность ствола скважины.

From the late 1900s onward, hydrocarbon exploitation has led to severe environmental footprints in the Khuzestan province, Iran. However, no comprehensive study has been conducted to evaluate such issues. In this research, an inclusive analysis was performed to investigate these environmental impacts. To do this, first, two datasets related to a 15-year period (2006–2021) were collated: the satellite data from the Sentinel-1 mission and the seismic data recorded by the National Iranian Geophysics Institute as well as the catalog of the global Centroid Moment Tensor project (CMT). These datasets were processed using generic mapping tools (GMT), differential synthetic aperture radar (D-InSAR) techniques, and multiple processing algorithms using a specific toolbox for oil spill application in the sentinel application platform (SNAP) programming, respectively. The results revealed three critical footprints, including regional earthquakes, land subsidence, and oil spill issues in the area. The most frequent earthquakes originated from depths less than 15 km, indicating the disturbance of the crustal tectonics by the regional hydrocarbons. Furthermore, an annual rate of land subsidence equal to 10–15 cm was observed in the coastal areas of the Khuzestan province. Moreover, two regions located in the north and west of the Persian Gulf were detected as the permanently oil-spilled areas. The applied methodology and results are quite applicable to restrict the harmful consequences of hydrocarbon production in the study area. This research will benefit not only government officials and policymakers, but also those looking to understand the environmental challenges related to oil and gas production, especially in terms of sustainable goals for the management of natural resources.

Finding a suitable location is a key factor for long-term investment in wind turbine energy. It includes understanding the area of interest, such as the subsidence of the land. Land subsidence is a gradual decrease in the surface of the Earth due to natural and/or induced causes. It can cause damage, such as settlement problems in the ground near infrastructure including buildings and wind turbines, thus not being a suitable place for long-term investment. Here, we show a case study of land subsidence prediction and assessment of the Atsimo Andrefana region, the great south-western part of Madagascar, using theoretical simulation and satellite images from the Sentinel-1 mission using D-InSAR method. The predicted land subsidence related to the depletion of groundwater reservoirs in the Atsimo Andrefana region is around 12 mm. We found ~5 mm of subsidence related to the growing city of Toliary and with an average subsidence of 124 mm and the highest record of 167 mm in the most southern part of the region for a period of 6 months. The spatial distribution of land subsidence allows us to choose the ideal location for wind turbine settlement, where land subsidence is not that severe, i.e., the areas with subsidence relatively low of equal or less than 10 mm within 6 months of observation, based on the processed data. Such results are essential for future environmentally friendly investments in the affected region, as the demand for green energy will always grow.

The gradual change in the Earth’s surface elevation is known as land subsidence and it happens due to natural causes related to geological activities, such as sinkholes, or induced causes related to human activities, such as mining activities, or both. The historical records of land subsidence show that it is mainly related to human activities with damages of more than billions of dollars every year. This paper shows the current trends of land subsidence case of the North-Central part of Poland using the Differential Interferometric Satellite Aperture Radar (DInSAR) technique. That region is known as the extension of the oil and gas reservoir of the Baltic Sea and one of the most populated areas in Poland. This technique uses SAR data images from the sentinel-1A mission of the same area, taken on April 25, 2018 and April 26, 2020, in order to measure the surface changes between these time intervals. Thus, a two-year land subsidence map of that region has been created, with maximum subsidence of -85mm. There is no significant subsidence in the production area, but information on the population supports the alleged reasons for such subsidence, namely the infrastructure growth and the need for water resources. Besides, most of the occurred subsidence in the concerned area is concentrated in big cities such as Gdansk and Gdynia. Such result is very important for policymakers, especially concerning the sustainable development goals

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informuj?ce swoich czytelnik?w o najnowszych osi?gni?ciach naukowych i nowoczesnych rozwi?zaniach technicznych w Polsce i na ?wiecie, popularyzuje problemy techniczne oraz poszerza wiedz? i kultur? techniczn?.