with Richard H. Fillon, 2006. "Biostratigraphy and Condensed Sections in Deepwater Settings", Introduction to the Petroleum Geology of Deepwater Setting, Paul Weimer, Roger M. Slatt, Renaud Bouroullec, Richard Fillon, Henry Pettingill, Matthew Pranter, Gabor Tari
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Biostratigraphic data are essential in understanding deepwater systems—at the well-site, and at regional and reservoir scales. Well site biostratigraphy plays an important role in daily drilling operations, specifically: (1) in the selection of casing or core points; (2) in the drilling of horizontal wells by helping place the well path (biosteering); (3) in helping address unexpected drilling results, such as unpredicted stratigraphic section or lithology; and (4) in helping determine if the well should be terminated because it may have penetrated below the objective section.
At a regional scale, biostratigraphy helps (1) place strata in a proper sequence strati-graphic (chronostratigraphic) framework by aiding stratigraphic correlations based on seismic and well log stratigraphy. (2) Biostratigraphy is especially important for stratigraphic correlation in basins with a strong structural overprint (syn- and/or post-depositional), and in intraslope basins where sands tend to pond in middle to lower bathyal water depths (Chapter 3). (3) Combined with absolute age dates, biostratigraphy helps estimate rates of sedimentary and structural processes within sedimentary basins. (4) Biostratigraphy helps in play concepts and/or in the trend analysis of depositional systems. (5) Biostratigraphy provides an independent basis for estimating paleo-water depths and paleo-environmental analysis. Benthic foraminifers, which are sensitive to environmental factors related to water depth, can be tied to seismic data to help clarify topset-foreset-bottomset relationships in expanded shelf margins.
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Introduction to the Petroleum Geology of Deepwater Setting
This publication is intended to provide the working geologist, geophysicist, and petroleum engineer with a broad overview of the petroleum systems of deepwater settings. Deepwater depositional systems are the one type of reservoir system that cannot be easily reached, observed, and studied in the modern environment, in contrast to other siliciclastic and carbonate reservoir systems. The study of deepwater systems requires many different remote observation techniques, each of which can only provide information on one part of the entire depositional system. As a consequence, the study and understanding of deepwater depositional systems as reservoirs has lagged behind that of the other reservoir systems, whose modern processes are more easily observed and documented. For this reason, geoscientists use an integrated approach, working in interdisciplinary teams with multiple data types. The types of data used in the study of deepwater deposits include: outcrop studies, 2D and 3D seismic-reflection data (both for shallow and deep resolution), cores, conventional and specialized log suites, biostratigraphy, and well test and production information. These data sets are routinely incorporated into computer reservoir modeling programs for production performance simulation and forecasting. Technologies for deepwater exploration and development are improving rapidly. The intent of this publication is to provide information that will be usable even as the technologies advance beyond what we present here.