Abstract: A system for multiple subsurface operations which are carried out in a well bore by means of two or more well tools having explosive or gas generating charges which are electronically initiated for accomplishing any number of other downhole well activities. Two or more well service tools are simultaneously run into a well on a single wire-line and are located at predetermined positions. An electronic blast control system having safety parameters, including time, movement, pressure and the like to ensure safe running and independent firing of the tools. The blast control system permits controlled energization of the explosive charges only when all of the programmed parameters have been met and causes sequential or serial electronic firing of the explosive devices independently of one another by positive and negative voltages.

Abstract: A method and apparatus for safely controlling detonation of a downhole explosive energized device which ensures that the explosive can be detonated in a well bore only when downhole hydrostatic pressure and well fluid temperature are within limits reflecting location of the explosive energized device at designed depth for accurate positioning relative to a selected formation. The apparatus further employs a clock/timer circuit and a motion sensor circuit to ensure firing of the explosive device only within a predetermined time period and only after having remained stationary within the well casing for a predetermined period of time. The apparatus further includes a memory circuit which receives and stores pressure and temperature data sets correlated with time which reflect well conditions before and after firing of the explosive device. After the tool has been retrieved from the well, this data is copied from the tool memory to a computer memory for subsequent computer processing and display.