The common reflecting element (CRE) method revisited

Abstract

The common reflecting element (CRE) method is an interesting alternative to the familiar methods of common midpoint (CMP) stack or migration to zero offset (MZO). Like these two methods, the CRE method aims at constructing a stacked zero‐offset section from a set of constant‐offset sections. However, it requires no more knowledge about the generally laterally inhomogeneous subsurface model than the near‐surface values of the velocity field. In addition to being a tool to construct a stacked zero‐offset section, the CRE method simultaneously obtains information about the laterally inhomogeneous macrovelocity model. An important feature of the CRE method is that it does not suffer from pulse stretch. Moreover, it gives an alternative solution for conflicting dip problems. In the 1-D case, CRE is closely related to the optical stack. For the price of having to search for two data‐derived parameters instead of one, the CRE method provides important advantages over the conventional CMP stack. Its results are similar to those of the MZO process, which is commonly implemented as an NMO correction followed by a dip moveout (DMO) correction applied to the original constant‐offset section. The CRE method is based on 2-D kinematic considerations only and is not an amplitude‐preserving process.