Fractured carbonate reservoirs constitute significant challenges in quantitative seismic reservoir characterization. The purpose of our study was twofold:
1) To investigate whether seismic attribute calibration could be used to develop and support the detailed 3D geologic modeling of the Kra Al-Maru discovery in Western Kuwait, and
2) To verify the applicability of ExxonMobil’s proprietary seismic attribute technology and integration process in predicting the most economically relevant reservoir property: its producibility.
We illustrate the key elements with the aid of a case study on the Jurassic-age Najmah and Sargelu Formations, an unconventional, naturally fractured, carbonate reservoir. The Minagish field was used as a producing analog of the Kra Al-Maru field. We used seismic forward modeling and well control from the Minagish, the Umm Gudair, and Kra Al-Maru fields to validate the results.
House, Nancy J. (Mobil New Exploration and Producing Ventures (NEPV)) | Cunningham, Paul S. (Mobil New Exploration and Producing Ventures (NEPV)) | Allen, K. Paul (Mobil Exploration and Producing technology(MEPTEC).) | Seyb, Stefan M. (Mobil Exploration and Producing technology(MEPTEC).) | Edleson, Lynne J. (Mobil Exploration and Producing technology(MEPTEC).)
In geologically complex fold and thrust terrains, recording conventional 2-D seismic is often so expensive that exploration companies acquire the minimum amount possible, any more being economically difficult to justify. Under these circumstances 3-D seismic data is often perceived as financially unreasonable, especially in the exploration phase of an evaluation. Such was the case for Mobil and partners in the Amazon rain forest in 1996 in an area known to be structurally complex. Under these conditions Mobil executed a ’Limited [low fold] Three Dimensional’ (LTD) seismic survey. The incremental cost of acquiring the 128 km2 LTD volume was approximately 5% of the cost of the conventional 2D data that was acquired to delineate the structure. Later interpretation of the volume resulted in decreased drilling costs, additional ‘proved reserves’, and better understanding of the complex internal structure drilled.
Weglein, Arthur B. (University of Houston, Houston) | Foster, Douglas J. (Phillips Petroleum, Bartlesville, OK) | Matson, Kenneth H. (BP, Houston, TX) | Shaw, Simon A. (BP, Houston, TX) | Carvalho, Paulo M. (Petrobras SA, Rio de Janeiro, Brazil) | Corrigan, Dennis (Arco)
Yu, Gang (Geospace Engineering Resources International) | Walter, Larry A. (Geospace Engineering Resources International) | Chmela, Bill (READ Well Services, THE AMERICAS) | Jahren, Leif (READ Well Services, THE AMERICAS) | O'Brien, John (Anadarko Petroleum Corporation) | Lime, Justin C. (Anadarko Petroleum Corporation)
The downhole orbital vibrator source originally developed by Conoco, Inc. operates as a free-hanging device in the fluid column on a standard 7-conductor wireline. An internal spinning eccentric mass produces a rotating force vector from the tool to the formation. This new downhole seismic source generates a 50 to 400 Hz bandwidth energy sweep, which is energized from a surface controller with programmable sweep length and start/stop times. The reference sweep is measured directly with horizontal geophones mounted inside the tool. This source produces robust horizontal radial energy with minimal tube wave generation in the fluid column. It is optimally suited to single well Imaging or UNIWELL type acquisition and crosswell seismic data acquisition.