Research article: Crosswel seismic reflection imaging of field datasets: the need for migration

A substantial amount of effort has been devoted to research in crossweIl seismology over the last 15 years, with parallel developments by several different groups resulting in a burgeoning literature. Here I want to focus attention on the imaging of multifold field datasets because an important difference is emerging between the methods used by various groups of workers. The difference lies between those who advocate migration of field datasets using the acoustic wave equation, and those who adhere to reflection point mapping, or some variant of it.