Fluvial sedimentology and chronostratigraphy improve reservoir characterization and resolve complex fluid distribution, Krasnoleninskoye area, Russian Federation, by Robert S. Tye. Jurassic-age strata from three formations in the Krasnoleninskoye area of the West Siberian Basin, Russia, form an aggregational, but overall trans-gressive continental to estuarine to shelf and basin succession filling alluvial valleys. Testing facies-association mapping methods showed that realizations using multiple-point statistics with geologically biased facies-association maps best represented facies heterogeneity and stratigraphic isolation of oil and gas reservoirs and the most likely positions and sizes of high net-to-gross areas i alluvial valleys.

Source rock deformation and hydrocarbon accumulation controlled by a metamorphic core complex in the northern South China Sea rifted margin, by Shan Zhong, Zhaoqian Liu, Guangrong Peng, Qing Ye, Lili Zhang, Xinming Xu, Simon C. George, and Lianfu Mei. The recent discovery of hundred-million-ton-class oil fields in the Kaiping sag, on the northern South China Sea rifted margin, is considered the first global breakthrough in hydrocarbon exploration within supra-detachment basins controlled by mature metamorphic core complexes at passive margins. The source rock distribution models, antithetic faults, and rotating fault blocks resulting from the Kaiping metamorphic core complexes can serve as a reference model for evaluating source rocks and analyzing hydrocarbon accumulation patters in similar-type basins.

Insights on fracture and karst cavern origin and diagenesis from core observations at Tengiz and Korolev fields, Kazakhstan, by Ted Playton, Evan Earnest, Fermin Fernandez-Ibanez, Assem Bibolova, Dana Tolessin, Ilyas Tussupbayev, and Bagdat Toleubay. The Tengiz and Korolev fields are giant, isolated carbonate platform reser-voirs located in western Kazakhstan. Oil production in these fields is dominated by naturally formed fracture and karst cavern networks. These networks around the fields are chiefy characterized using static logs, dril-ing data, and dynamic data from surveillance. This study uses the extensive core data set available from Tengiz and Korolev to better understand the genetic origins, spatial distributions, and diagenetic evolution of the fracture-karst networks around the fields.

Fracture characterization from core and image log integration at Tengiz and Korolev fields, Kazakhstan, by Ted Playton, Evan Earnest, Fermin Fernandez-Ibanez, Assem Bibolova, Dana Tolessin, Ilyas Tussupbayev, and Bagdat Toleubay. Tengiz and Korolev fields in western Kazakhstan are, in part, fed from naturally formed nonmatrix networks (here defined as fractures, karst caverns, and smaller karst features). Borehole image logs are the primary tool for identifying and documenting fractures and karst caverns at wells due to their substantial reservoir coverage; however, core data sets, although much more spatially limited, provide critical ground truth for fracture presence and other characteristics. This paper highlights the value of core in addressing the limitations and improving the accuracy of log-based fracture characterization and can be applied to other fields and reservoir settings.

Direct evidence for abnormal overpressure generated by crude oil cracking in the Sinian Dengying Formation, Central Sichuan Basin, southwestern China, by Yifan Song, Yong Chen, Tong Lin, Miao Wang, and Hui Tian. According to conventional views, cracking of oil to gas is expected to occur in sedimentary petroliferous basins. Recognition of exceptionally high pressure generated as a result of this process is crucial for evaluating the accu-mulation and preservation conditions of natural gas and fluid inclusions in associated minerals can provide direct evidence. The presence of methane•bitumen two-phase inclusions in the Sinian Dengying Formation in the Sichuan Basin is a significant finding. This information can give a valuable reference for the understanding of the preservation conditions of cracked gas reservoirs in sedimentary basins and is particularly useful in guiding future oil exploration and development efforts.