The Location of Major Oil‐ and Gasfields: Examples From the Andean Foreland

Abstract

In all producing basins, most of the oil and/or gas reserves are concentrated in a minority of fields. This distribution of oil and gas reserves is the result of “focusing” during lateral and vertical basin‐wide migration. Although the physico‐chemical and geological processes involved in hydrocarbons migration are not yet fully clarified, lateral migration directions can be established by integrating geological, geophysical and geochemical data. The Petroleum Systems concept is of use here. When combining Petroleum Systems data with well‐controlled regional structure maps, areas of hydrocarbons concentration (i.e. migration focusing) can be defined as areas of the highest exploration potential. Some basic petroleum‐geological data are reviewed from the Eastern Venezuela Basin and the Llanos Basin region in Colombia. By using published Bouguer gravity maps as regional structural form‐line maps, areas of preferred lateral migration are shown to be areas of maximum hydrocarbon accumulations. This leads on to an exploration approach in which Petroleum Systems data and regional (gravity or other) structure maps are used to evaluate acreage for its exploration value with a minimum expenditure of time, manpower and related funds.

Application of seismic stratigraphy and structural analysis in the determination of petroleum plays within the Eastern Niger Delta Basin, Nigeria

“…Such lateral Fig. 11 Upper oligocene to eocene-deep Eastern Niger Delta petroleum plays hydrocarbon migration will utilize subsurface pressure systems which, in turn are controlled by basinal geometries (Pratsch 1982(Pratsch , 1994. From this study, it was discovered that the location of reservoirs at areas of closely spaced listric fault informally called K-type faults most often occur at the hanging wall just behind the fault plane as blocks become rotated updip into a more landward direction (Figs.…”

Preferential petroleum migration pathways in eastern Pearl River Mouth basin, offshore South China Sea

“…A number of workers believed that the migration pathways in heterogeneous carrier beds are primarily controlled by permeability heterogeneities, with petroleum preferentially migrating through carrier-bed portions with relatively high permeability (e.g., Bekele et al, 2002Bekele et al, , 1999Rhea et al, 1994). Many others believed that, even in heterogeneous carrier beds, the petroleum migration pathways are controlled largely by structural morphology (Hindle, 1997;Pratsch, 1994Pratsch, , 1988Pratsch, , 1986Pratsch, , 1983Momper and Williams, 1984).…”

“…Therefore, they are difficult to effectively predict because of complications with characterizing permeability heterogeneity related to the extent of fracture permeability and permeability alteration due to diagenesis (Bekele et al, 2002). Nevertheless, others believed that petroleum migration pathways are controlled largely by structural morphology (Hindle, 1997;Pratsch, 1994Pratsch, , 1988Pratsch, , 1986Pratsch, , 1983Momper and Williams, 1984), and modeling of petroleum migration pathways can be a powerful tool to reduce exploration risk (Hindle, 1999(Hindle, , 1997Hermans et al, 1992;Sylta, 1991).…”

“…The migration pathways control the dis- tribution of oil and gas in sedimentary basins (Bekeleet al, 2002;Hindle, 1997;Pratsch, 1994;Demaison and Huizinga, 1991). Clear understanding of petroleum migration pathways is therefore of great significance for optimizing petroleum exploration in an intensively explored area.…”

Reconstruction of the Cenozoic History of Hydrocarbon Fluids from Rifting Stage to Passive Continental Margin Stage in the Huizhou Sag, the Pearl River Mouth Basin

“…However, the nature of petroleum migration pathway is still controversial. Some researchers [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] believed that the petroleum fluids migration is mainly driven by structural morphology, and modeling of petroleum fluids migration pathways can be a powerful tool to reduce exploration risk. Others [27][28][29][30][31] propose that petroleum fluids tend to pass through a high-permeable, thin sandstone bed than through a low-permeable and thick sandstone bed, controlled by the heterogeneity of the porosity and permeability of the carrier beds.…”