The success of Memoir 14 and the worldwide interest shown for data on giant fields prompted AAPG to schedule a symposium on giant fields at the end of each subsequent decade. The 1968-78 symposium was held in Houston, Texas, April 1-4, 1979, and the papers were published in AAPG Memoir 30, December 1980.The Stavanger Conference "Giant Oil and Gas Fields of the Decade: 1978-1988" was held in Stavanger, Norway, September 9-12, 1990, and is a continuation of the Giants of the Decade series.Scientific studies and projections of future world energy demand indicate that although alternative-energy fuel sources must be actively pursued and developed, there also must be adequate petroleum supplies to bridge the gap. For the international petroleum industry, the years covered by this conference, 1978-88, were complex. They were years of boom and bust. The world's energy consciousness was boosted sharply by the effects of the 1979 Iranian revolution and the resulting embargo, which sent world oil prices to record heights. Global petroleum exploration soon surged, leading to the industry's all-time drilling high in 1981. Then came the oil price collapse in 1985, and the following years were characterized by falling oil prices and drastic budget cuts for exploration and development.Although exploration dropped sharply during the latter part of the decade, there was a steady flow of giant oil and gas field discoveries. Using the giant field designation criteria of 500 million bbl of oil recoverable for fields in Asiatic Russia, North Africa, and the Middle East,
CH 4 and CO 2 species in pore fluids from slope sediments off Guatemala show extreme 13 C-enrichment (δ 13 C of -41 and +38‰, respectively) compared with the typical degree of 13 C-enrichment in pore fluids of DSDP sediments (δ 13 C of -60 and + lO‰).These unusual isotopic compositions are believed to result from microbial decomposition of organic matter, and possibly from additional isotopic fractionation associated with the formation of gas hydrates.In addition to the isotopic fractionation displayed by CH 4 and CO 2 , the pore water exhibits a systematic increase in δ 18 θ with decrease in chlorinity.As against seawater δ 18 θ values of 0 and chlorinity of 19‰, the water collected from decomposed gas hydrate from Hole 570 had a δ 18 θ of + 3.0‰ and chlorinity of 9.5‰.The isotopic compositions of pore-fluid constituents change gradually with depth in Hole 568 and discontinuously with depth in Hole 570.
The basic data for evaluation of the petroleum source=rock potential in the National Petroleum Reserve in Alaska are summarized on the accompanying 39 plates. These data consist of organic geochemical analyses and observed hydrocarbon occurrences in 63 Government-drilled wells located in and adjacent to the NPRA. To relate the geochemistry to the geology, the authors have also included geophysical well logs, lithology, rock units, paleontologic zones, and ages. Two additional wells, Iko Bay No. 1 and Teshekpuk No. 1, are included here even though they lack geochemical data because they were drilled during the latest exploration program and provide information on subsurface geology and hydrocarbon occurrences. These displays, in addition to being the culmination of a considerable team effort, also demonstrate the capabilities of the NPRA computer system. All of the data displayed are stored in various computerized files. All data were computer-plotted except for the columns showing age, paleontologic zones, and stratigraphic names. Magoon and Claypool are responsible for the geochemical data and plate format design, Bird for the geologic and paleontologic summary, Weitzman for the computer programming and file construction, and Thompson for the data on hydrocarbon occurrence.
The Alaska North Slope oil-rock correlation study was organized because several oil companies requested oil and rock samples for geochemical analyses that were recovered during the exploration drilling in the National Petroleum Reserve in Alaska (NPRA). Samples acquired with public funds could not be given to private organizations unless some guarantees could be provided that the information acquired from these samples could be made available to the public. For this reason, in August 1981, we sent out over 40 invitations to research laboratories in industry, government, and academia.Requirements to participate in this study included: (1) participation in an AAPG-sponsored research conference, (2) presentation of the data interpretations at the 1983 Annual AAPG Meeting in Dallas Texas, and (3) contribution of a manuscript, to include all acquired data and interpretations, that would be included in a symposium volume. If a research group wished to participate, they were to write a letter of intent that included their proposed analytical program and a statement indicating that the requirements would be adhered to by their group. Even with these stringent requirements, 30 research groups wished to participate. A balanced cross section of research groups are participating and are as follows: 15 from oil companies, 7 from commercial laboratories, 7 from government laboratories, and 1 university laboratory. These groups are listed in Table 1.In January 1982, each research group was sent 8 oils and 15 rocks recovered from NPRA drilling and 1 oil from the Prudhoe Bay field. Each group then proceeded to analyze these samples as they indicated in their letter of intent.
