Enhance Seismic Quality With A Fast, Robust and Economic Solution Using Broadband Technology

Abstract

Often many companies doing seismic reprocessing project with the latest advanced seismic processing technology to handle their seismic problems. This kind of solution might work for some companies but certainly will not for many others. Innovative solutions are required to overcome seismic problem or issue considering time, budget and technical robustness. The objective of this paper is to demonstrate a seismic processing project that was run in a relatively low oil price condition, to handle a low seismic resolution problem in thinly bedded reservoirs. In addition to budget and technical constraints, timing and schedule is also an issue since the updated interpretation is required to be used for updating a static model in less than a 3 months time window. A broadband processing method on 100 km2 post-stack 3D seismic data was applied to enhance frequency content which leads to enhanced seismic resolution to resolve objective reservoirs. This method is considered fast, robust and economical. The procedure would be enhancing the spectrum by designing a unique filter into the dataset after inverse Kirchhoff migration application. After some iterations, forward Kirchhoff migration and multi spatial time-variant filter was applied to generate the desired output. Overall processing time was completed within budget in a one-month period only. As a result, forty percent (40%) increase in dominant frequency was achieved as final deliverables from 25Hz to 35Hz. The original dataset with 25Hz dominant frequency can only resolve reservoirs with thickness greater than 20m. The thickness of individual objective sandstone reservoirs in the study area was ranging from 1.5m to 20m with average thickness around 6-10m. However, stacked reservoir thickness within the same flooding surface interval of the same unit is relatively thicker than 10m. The 35Hz dominant frequency data from broadband processing can resolve reservoir with thickness greater than 14m and better resolve stacked reservoirs even though very thin reservoir below resolution remains unresolved. Broadband seismic technology on post-stack dataset offers a fast, robust and economical solution focused on target which can be duplicated in other area/data to provide successful interpretation projects.