Challenges in Seismic Data Acquisition and Processing - The Petronas Experience

Abstract

This reference is for an abstract only. A full paper was not submitted for this conference. Abstract PETRONAS has been actively acquiring large volumes of seismic data in varied and difficult terrain to support its worldwide exploration, development and production activities. In the Malay Basin of Malaysia, the challenge begins with imaging complex stratigraphic reservoirs that are often below conventional seismic resolution. The Malay Basin being a fairly matured exploration & production province also poses another challenge, i.e. acquiring high quality seismic data around platforms and other obstructions. In Vietnam, our team was tasked with imaging complex fractured basement reservoirs under an overburden of clastic and volcanic rocks while in Indonesia, obtaining high quality, contiguous data over a land-marine interface required four different acquisition techniques and special processing workflows. In offshore Mozambique, East Africa where strong currents prevail in a N-S direction, binning and stacking methodology was used to ensure a thorough reflection of the subsurface. The high elevation changes in the mountainous region of Yemen called for a special array design, dual elevation and hybridstatic routines, while under the dunes of Algeria, the low relief structures needed proper accounting of static variation through modeling. This paper outlines the various technical challenges faced in the above regions and the solutions that were designed for them. While specific solutions are required in special circumstances, PETRONAS underlying objective is to acquire optimal data that will last the life cycle of a field where the surveys form the base cases for eventual reservoir monitoring through 4D seismics. Imaging through gas clouds, detection of fractures and improving resolution of thin pay sands and seals are some of our continuing challenges. With strong focus on proactive resolution of technical issues, the operational challenge of striking the right balance between quality, cost and efficiency is managed. Health and safety and preservation of the environment during seismic operations remain as an underlying principle of PETRONAS.