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4D Seismic Pilot Successfully Interprets Carbonate Reservoir

This paper describes interpretation results of a 4D seismic-monitoring program in a challenging Middle East carbonate reservoir. The program consists of a 4D pilot [oceanbottom cable (OBC)] over a giant field divided into two phases. The authors discuss the difficulties faced by both phases of the pilot, and prove that a reliable 4D signal can be extracted over a Middle East carbonate reservoir.

Introduction

The time-lapse, or 4D, seismic method consists of repeating seismic survey acquisitions over the production time of a field. Newer vintages are compared with previous ones, and the signal differences are interpreted to characterize effects of the production spatially. Though this technique is mature and has been widely used in clastic reservoir environments, it is still used rarely, in operational terms, to monitor carbonate fields.

An opportunity for a 4D proof-of-concept program in a Middle East marine carbonate environment was identified during a new OBC seismic acquisition in 2013. While the survey was intended for 3D imaging purposes, the operator decided to acquire a 4D pilot over a test area of approximately 25 km2 (Phase 1) while repeating as best as possible the 1994 acquisition design (baseline for this 4D study). The goal was, first, to process this test, and then, if a reliable 4D signal (above noise level) could be established, to propose interpretation in accordance with the field-production mechanisms.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 193063, “A Successful 4D Seismic-Monitoring Pilot in a Middle East Carbonate Reservoir Context,” by F. Cailly, T. Al-Romani, C. Hubans, and A. Lafram, Total, and A. Al Kaabi, ADNOC, prepared for the 2018 SPE Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 11–14 November. The paper has not been peer reviewed.
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4D Seismic Pilot Successfully Interprets Carbonate Reservoir

01 March 2019

Volume: 71 | Issue: 3

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