Multimeasurement Streamer Research Articles

Seismic acquisition and imaging strategies for unlocking subsurface complexities in Malaysian basins

Seismic data acquisition and imaging technologies have made important contributions to hydrocarbon discoveries and enhancing recovery from existing reservoirs in Malaysian basins. PETRONAS has been leveraging these technologies to address the exploration and development challenges encountered in Malaysian basins and other parts of the world and to support its play-based exploration. Some of the key technology applications include imaging below shallow gas and carbonates, imaging of complex geology for exploring deep water and deep plays, and high-resolution imaging of shallow clastic plays. Dual and multimeasurement streamers, multiazimuth and full-azimuth seismic, triple- and penta-source blended acquisition, and two- and four-component seabed seismic technologies have been integrated with high-end processing and imaging technologies such as advanced demultiple techniques, deblending, full-waveform inversion, reverse time migration, and PS-converted wave imaging to address complex subsurface challenges. In this article, we present an overview of the evolution and application of innovative seismic acquisition and imaging technologies in Malaysian basins. Selected case histories demonstrate how these technologies have enabled explorers to unlock subsurface complexities, adding value to exploration and development activities. We share the advancements in 3D seismic survey design, marine streamer acquisition, seabed seismic acquisition, and seismic imaging technologies, and how an integrated approach helped PETRONAS address geologic challenges to enhance its exploration success.

Evolution of Marine Acquisition Technology after Wide Azimuth

Seismic exploration in the deep-water Gulf of Mexico was based for many years on the 3D acquisition method and, as a result, significant oil discoveries were made and most of the plays were found below salt or in intra-salt-body basins. The quality of the seismic data acquired in deep-water subsalt environments was occasionally satisfactory for exploration purposes, but, in most cases, it was not good enough to support an accurate earth model for reservoir development. The main challenges for data interpretation are: incomplete reservoir illumination, poor signal-to-noise ratio of the subsalt events and poor seismic resolution. Developments in the last decade in marine seismic acquisition and data processing were driven to solve these challenges. One reference point in the evolution of marine seismic technology in the last decade was the introduction of wide azimuth acquisition (WAZ). Introduced in 2006 by British Petroleum in the Gulf of Mexico, the method was quickly adopted by the industry as a seismic technology to explore the complex subsalt geologic structures where improved subsurface illumination and signal-to-noise ratio are required. The introduction of WAZ started a period of several innovations in the seismic industry: dual-sensor streamer acquisition, full-azimuth towed streamer acquisition, broadband seismic measurements on both the source and receiver sides, long-offset marine acquisition, simultaneous shooting, and multimeasurement streamers. Challenges in processing wide-azimuth data lead to new developments in velocity model building based on tomography and full-waveform inversion, 3D demultiple methods, 3D anisotropic imaging with reverse time migration, and other improvements in computational methods. The presentation will review the latest innovations in marine seismic acquisitions with examples of applications, and will discuss the geophysical benefits and limitations, as well as specific survey design and processing aspects related to each method.

Towards improved time-lapse seismic repetition accuracy by use of multimeasurement streamer reconstruction

Patrick Smith, Jason Thekkekara, Julie Branston, Grant Byerley, David Monk and Jeffrey Towart describe, with an example from the North Sea Forties field, how multi-measurement streamer technology enables the reconstruction of a monitor survey to the streamer locations and datum of a previous survey, thus improving time-lapse repeatability.