Preferential petroleum migration pathways and prediction of petroleum occurrence in sedimentary basins: A review

Abstract

The aim of this paper is to review the major points of contention concerning secondary petroleum migration, to discuss the nature and primary controls of the positions of petroleum migration pathways in sedimentary basins, and to illustrate the importance of preferential petroleum migration pathways for the formation of large oil/gas fi elds away from generative kitchens. There is competition between the driving force (buoyancy) and the restraining force (capillary pressure controlled largely by permeability contrast) in controlling the positions of petroleum migration pathways in heterogeneous carrier beds. At a large scale, there is a critical angle of dip of the carrier beds which determines the relative importance of structural morphology or permeability contrasts in controlling the positions of petroleum migration pathways in heterogeneous carrier beds. Maximum-driving-force-controlled migration pathways occur in carrier beds with an angle of dip greater than the critical dip and the positions of petroleum migration pathways are controlled mainly by the morphology of the sealing surfaces. Minimum-restraining-force-determined migration pathways occur in carrier beds with an angle of dip smaller than the critical angle where permeability contrasts would exert a more important infl uence on the positions of petroleum migration pathways. Preferential petroleum migration pathways (PPMP), defi ned as very restricted portions of carrier-beds that focus or concentrate petroleum from a large area of the generative kitchen, determine the distribution of oil and gas in sedimentary basins. The focusing of petroleum originating from a large area of the generative kitchens into restricted channels seems to be essential not only for long-range petroleum migration in hydrostatic conditions, but also for the formation of large oil or gas fi elds. Regions may miss out on petroleum migration because of its three-dimensional behavior, and two-dimensional migration modeling may be misleading in predicting petroleum occurrences in certain circumstances.

Hydrocarbon-Generating Potential of the Upper Paleozoic Section of the Huanghua Depression, Bohai Bay Basin, China

“…1−3 The Huanghua Depression is located in the central region of the Bohai Bay Basin, with significant, proven conventional oil reserves having been discovered from Paleogene and Neogene structural traps. 4,5 Successful production of unconventional shale oil from the Paleogene Kongdian Formation has been reported. 6 The Huanghua Depression has experienced almost 60 years of exploration, and the oil exploration has primarily focused on buried-hill hydrocarbon reservoirs that were charged from Paleogene lacustrine mudstones in the Shahejie Formation.…”

The relationship between dolomite textures and their formation temperature: a case study from the Permian-Triassic of the Sichuan Basin and the Lower Paleozoic of the Tarim Basin

“…The origin of dolomites and dolomitized carbonates has long been an interesting topic in carbonate sedimentology. Geochemical and petrographic data have been used to identify the Mg source, the mechanism of fluid delivery, and the environmental setting favorable for dolomitization, and multiple dolomitization models have been developed to explain the origin of extensive, thick successions of dolostones (Warren, 2000;Hao et al, 2010). Compared with a focus on these macro-scale issues, little consideration has been given to the genetic implication of dolomite textures, and this may be attributed to inadequate textural description.…”

The coupling of dynamics and permeability in the hydrocarbon accumulation period controls the oil-bearing potential of low permeability reservoirs: a case study of the low permeability turbidite reservoirs in the middle part of the third member of Shahejie Formation in Dongying Sag

“…Only when the dynamic force surpasses the resistance force, can petroleum seep into rocks and form petroleum reservoirs (Hao et al 2010). We calculated the cutoff-values for porosity and permeability in the accumulation period under the constraint of accumulation dynamics and pore throat structure ).…”