Exploration and Mining
Amin Jamshidi
Abstract
Accurate estimation of the rotary drilling rate of the rock can save time and cost on exploration operations of the geotechnical projects such as dams, tunnels, oil and gas wells and building stone mines. In this study, the rotary drilling rate in limestone is estimated based on brittleness indices. ...
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Accurate estimation of the rotary drilling rate of the rock can save time and cost on exploration operations of the geotechnical projects such as dams, tunnels, oil and gas wells and building stone mines. In this study, the rotary drilling rate in limestone is estimated based on brittleness indices. To achieve this goal, the values of rotary drilling rate, Uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) were determined in three exploratory wells drilled in limestone. Based on the data, the regression relationships of one, two and three variables between rotary drilling rate as a dependent parameter and brittleness indices as an independent parameter were developed. The results suggest that based on one- and two-variable regression relationships, rotary drilling rate can be estimated based on brittleness indices with relatively good accuracy. In addition, the results showed that the three-variable regression relationship was more accurate than the one- and two-variable in estimating the rotary drilling rate. Finally, the three-variable relationship presented in this study could be appropriate in the early stages of exploration operations for geotechnical projects in limestone, which saves time and money.
M. R. Nikudel; A. Jamshidi; N. Hafezi moghaddas
Abstract
Abstract
Acid rain is one of problems due to air pollution. In areas with polluted atmosphere, SO4 and NO3 are among most important contaminator, which constitutes sulfuric and nitric acids solutions, as a result of combining with hydrogen ions. Also, these solutions are among important agents ...
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Abstract
Acid rain is one of problems due to air pollution. In areas with polluted atmosphere, SO4 and NO3 are among most important contaminator, which constitutes sulfuric and nitric acids solutions, as a result of combining with hydrogen ions. Also, these solutions are among important agents in building stones dissolution and deterioration. Regarding the involved acid and its pH, these solutions have different effects on stones. In this research, we selected 14 building stones samples of different origins. Then, in order to investigate their dissolution and deterioration and, also comparing sulfuric and nitric acids dissolving effect, we performed Durability Test up to 15 cycles, and calculated Durability Index on mentioned solutions - with pH = 1.5, 3, and 5, and also fresh water with pH = 7.3. The results show that the samples with non-carbonate composition are resistant against those acids, while the carbonate ones are not. Furthermore, comparing results of Durability Index indicates that sulfuric acid has 0.06 to 0.93% greater dissolving effect than nitric acid. In addition to, a decrease in both acids pH, leads to a greater dissolution of carbonate samples. Finally, according to obtained results, we recommended the most suitable stones for exterior façade of buildings.
