Testing the effectiveness of multi-layer target penetration by linear shaped charges

Although the cumulative detonation phenomenon is well-known and used in shooting techniques all over the world, the oil industry continues to search for an oil and gas well completion method of the highest possible effectiveness. Utilisation of explosives in shaped charges intended for perforation jobs provides effective hydraulic connection of the borehole with the reservoir, but local adverse effects of detonation remain in place in the form of crushed and damaged zones around the perforation channels. The work proposes new insight into methods of perforating boreholes. Although still within the domain of explosives, it presents a method of perforation based on the use of linear shaped charges, whose action is boosted by the energy of the combustion of the propellant. The work presents the course and results of four shooting experiments with a conceptual perforating and fracturing tool with the working name of ‘fracperforator’, the main task of which is the penetration of a multi-layered target comprised of diversified materials, whose downhole structure represents a borehole. The presented tests were directed for studying the effectiveness of steel/water/concrete system perforation. In the course of the study, fears were dispelled that concerned of all armed charges initiating and the occurrence of phenomenon producing damage to the tool before the operation was completed. However, the hypothesis of thorough modernisation of the linear shaped charges was confirmed, as in the current form they release too much energy outside the axis of cumulative jet action. The subject energy losses firstly reduce the charge action strength, and secondly cause damage to the body pipe as the load carrying part, by extensive bulging and tearing. The analysis of the created cumulative slots enables one to state that they are uniform and no significant changes of their width are observed. The depths or range of the slots have not been determined at this stage of work because of complete damage of the concrete part of the models simulating the lengths of borehole. The completed tests, performed in the form of four shooting experiments, confirm the ability of linear shaped charges to effectively penetrate multi-layered targets.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).