A comprehensive investigation to determine the initiation power of detonators containing as a base charge the novel explosives: dihydroxylammonium 5,5′‐bis(tetrazolate‐1N‐oxide) – TKX‐50, dihydroxylammonium 5,5′‐bis(3‐nitro‐1,2,4‐triazolate‐1N‐oxide) – MAD‐X1, pentaerythritol tetranitrocarbamate – PETNC and 3,3′‐diamino‐4,4′‐azoxyfurazan – DAAF in comparison with RDX, HMX and PETN was undertaken. In order to estimate the initiation power of the detonators, the underwater initiating capability test was used. The total energy as a sum of the primary shock wave energy and the bubble gas energy was determined for each of these explosives, by measuring the overpressure of the shock waves generated in water. Moreover, the complete synthesis for novel explosives is presented. The thermal behavior of the explosives was investigated using DSC (differential scanning calorimetry). The gas phase absolute molar enthalpies at 298 K and 105 Pa were calculated theoretically using the modified complete basis set method (CBS‐4M; M referring to the use of minimal population localization) with the Gaussian 09 software. Gas phase standard molar enthalpies of formation (ΔHf°(g)) at 298 K were computed using the atomization energy method. Standard molar enthalpies of formation (▵H(s)°) were calculated using ΔHf°(g) and the standard molar enthalpies of sublimation by applying Trouton’s rule. The Chapman‐Jouguet (CJ) characteristics based on calculated ▵H(s)° values were computed using the EXPLO5 V6.01 thermochemical computer code. For the calculations the theoretical maximum densities and densities obtained during the experiments presented in this work were used.

Ongoing research to find new explosives which are stable at high temperatures focuses on compounds which comply with the strict requirements which must be fulfilled in order for a compound to be of use in deep oil-well and gas drilling applications. Great efforts have been focused on the development of new, thermally stable explosives which are stable at even higher temperatures than hexanitrostilbene, and which also show superior performance. In the group of recently synthesized thermally stable explosives, 5,5'-bis(2,4,6-trinitrophenyl)-2,2'-bi(1,3,4-oxadiazole) (TKX-55) is one of the most promising prospective candidates for use in practical applications, due to its physicochemical properties as well as its convenient synthesis. Therefore, further investigation into the performance of TKX-55 in shaped charge applications was undertaken. This study was focused on the investigation of the jet penetration capability of conical shaped charges filled with TKX-55, in comparison with recently used other explosives. The kinetic energy of the jet depends on the brisance of the explosive which is used. In order to experimentally investigate the shattering effect of TKX-55, the Underwater Explosion Test was applied. Based on the collected data, the total energy, as the sum of the primary shock wave energy (the brisance) and the bubble gas energy (the heaving effect), was calculated.

This paper investigates the possibility of using ammonium nitrate(V)-based solid propellants for fracturing wells in borehole mining. Various modified propellant compositions with ammonium nitrate(V) and polyurethanes were prepared. Using laboratory rocket motors (LRMs) and underwater tests in pressure chambers, the energetic parameters (i.e., maximum pressure of the gaseous products and pressure impulse) for the selected AN-propellants were determined. Furthermore, thermodynamic analyses for these propellants were performed. The influence of the proposed additives on the energetic parameters (i.e., calorific value and specific energy) was shown. The gas volume generated per unit volume of propellant, which is an important parameter in the process of hydraulic fracturing, was estimated.

Ocena dynamiki spalania propelantów w środowisku węgla kamiennego Artykuł opracowano na podstawie wyników badań zrealizowanego projektu szczelinowania gazowego próbek węgla kamiennego z wykorzystaniem materiałów wysokoenergetycznych-propelantów, w skali laboratoryjnej. Założeniem projektu było sprawdzenie, czy metoda stymulacji przepływu mediów ze złoża do odwiertu, znana z zastosowań w przemyśle naftowym przy konwencjonalnych złożach węglowodorów, może zostać wykorzystana w przypadku złóż metanu z pokładów węgla kamiennego (CBM). Metoda szczelinowania gazowego z zastosowaniem materiałów wysokoenergetycznych opiera się na niedetonacyjnym wykonaniu kilku radialnych szczelin w strefie przyotworowej, poprzez oddziaływanie ciśnienia gazów prochowych, powstałych w wyniku inicjacji propelantów. Zakres pracy obejmował serię testów szczelinowania gazowego w warunkach poligonowych na próbkach węgla kamiennego, które zostały zeskanowane tomografem komputerowym, przed i po próbach ciśnieniowych z wykorzystaniem materiałów wysokoenergetycznych. Zabieg szczelinowania wykonano w laboratoryjnym silniku rakietowym (LSR), odpowiednio dostosowanym do badań na próbkach węgli. Uzyskane obrazy spękań poddano analizie porównawczej z obrazami pierwotnej sieci spękań w węglach oraz opisano występujące pomiędzy nimi różnice. Dodatkowo przeanalizowano wykresy ciśnienia w komorze silnika laboratoryjnego, powstałe w trakcie badań.

No abstract