Spectral Attenuation Analysis in a Mexican Mature Oil Field

Seismic attenuation analysis is used to distinguish changes in the spectral and amplitude characteristics of the seismic signal with the purpose of identifying the presence of fluid and fractures within the rock system. The analysis of such chances can be used as a tool for characterizing rock properties and for understanding the behaviour of wave propagation in a complex environment composed by pores and cracks containing fluids. The study is carried out using high-resolution reflection data obtained from a mature fractured carbonate reservoir near the northeast coast of Mexico. Production from this reservoir is declining considerably. For that reason, a horizontally drilling program is considered. The result obtained from in situ measurements indicates that the spectral changes and attenuation anomalies are related to the presence of hydrocarbons on the fractured reservoir rocks; however, such anomalies are also related to the highly fractured areas due to wave scattering. The seismic attenuation patterns associated to productive zones helped to identify new potential areas and in assisting for horizontal drilling targets.