A gun to gun transfer delay fuse that includes a delay housing, a first cylindrical cavity housing a firing pin and igniter, and a second cylindrical cavity housing a delay fuse with a centralizer feature.

A mechanical gun to gun delay for providing a desired time delay between the firing of a first gun and the firing of a second gun downhole without using a pyrotechnic fuse as the delay.

A mechanical gun to gun delay for providing a desired time delay between the firing of a first gun and the firing of a second gun downhole without using a pyrotechnic fuse as the delay

A method can include receiving seismic survey data of a subsurface environment from a seismic survey utilizing water bed receivers, where each of the receivers includes a clock; assessing one or more clock calibration criteria; based on the assessing, selecting a clock drift processor for processing at least a portion of the seismic survey data from a plurality of different clock drift processors; using at least the clock drift processor, performing a simultaneous inversion for values of model-based parameters; and, using at least a portion of the values, generating processed seismic survey data that represents one or more geological interfaces in the subsurface environment.

A method can include receiving seismic survey data of a subsurface environment from a seismic survey utilizing water bed receivers, where each of the receivers includes a clock; assessing one or more clock calibration criteria; based on the assessing, selecting a clock drift processor for processing at least a portion of the seismic survey data from a plurality of different clock drift processors; using at least the clock drift processor, performing a simultaneous inversion for values of model-based parameters; and, using at least a portion of the values, generating processed seismic survey data that represents one or more geological interfaces in the subsurface environment.

A gun to gun transfer delay fuse that includes a delay housing, a first cylindrical cavity housing a firing pin and igniter, and a second cylindrical cavity housing a delay fuse with a centralizer feature.