Patent ID: 8517120
Filing Date: 2013-08-27
Classification: E21B,F42C,F42D

Abstract:
1. A perforation tool for perforation of a formation or a well downhole by detonation of a charge, comprising: at least one charge, and at least one switch for detonation of the at least one charge, wherein the switch comprises: a housing, at least one contact means fixed in the housing, a shaft having a longitudinal axis and a first end with a fastening means enabling a fastening of the shaft in a predetermined position in relation to the housing, the shaft being extendable within the housing along the longitudinal axis, and a conductive means fixed on the shaft and providing an electrical current to be conducted between the contact means and the conductive means when the contact means and the conductive means are in electrical contact with each other for detonation of the at least one charge wherein the fastening of the shaft is configured to maintain along the longitudinal axis a relative position between the at least one contact means and the conductive means substantially constant in an absence of an influence of power means and allow the relative position between the at least one contact means and the conductive means along the longitudinal axis to change under the influence of the power means to enable detonation of the at least one charge when the contact means and the conductive means are brought into electrical contact with each other, and wherein the fastening means is a screw thread that interacts with at least one of an internal thread of the housing and a gear means of the perforation tool for driving the conductive means on the shaft into and out of contact with the contact means.