[1]4 Integrated Use of Hydrodynamic, Geochemical and Geothermal Data for the Basin-Scale Identification of Hydrocarbon Generation, Migration Paths and Major Accumulations, with Examples from the Alberta, Williston and Llanos Basins

[1]4 Integrated Use of Hydrodynamic, Geochemical and Geothermal Data for the Basin-Scale Identification of Hydrocarbon Generation, Migration Paths and Major Accumulations, with Examples from the Alberta, Williston and Llanos Basins

Hydrocarbon exploration leads to a collection of stratigraphic, lithologic, rock-properties, hydrodynamic, geothermal, hydrochemical and geochemical data. These data are unevenly distributed, of variable quality, and usually are analyzed separately. Culling erroneous data, deriving additional information, and integration of all the data is conducive to a comprehensive analysis of basin evolution and processes. This provides a basis for the conceptual, large-scale understanding of hydrocarbon generation, migration and accumulation in a basin, which, in turn, could be used as a tool for better-targeted, local-scale exploration and discovery of hydrocarbons.The approach is exemplified for the mature Alberta and Williston basins in Canada and US., and the developing Llanos basin in Colombia. Hydrocarbon migration and accumulations in the Alberta basin, including huge tar sands deposits, and in the Williston basin, were controlled by stratigraphy and structure, and by several flow systems driven by different mechanisms. Low rock permeability led to incomplete flushing of the original formation waters, and a conduction-dominated geothermal regime. The Llanos basin is characterized by high rock-permeability, being probably flushed of the original formation waters. The geothermal regime is controlled by both conduction and convection. Hydrocarbons migrated updip and have been flushed out of the basin unless caught in stratigraphic, structural or hydrodynamic traps.Hydrocarbons are the main economic resource in sedimentary basins around the world, although mineral deposits are also present in places. Thus, a large amount of activity is directed toward exploring for and developing these resources. As a result, many categories of data are collected in the field, processed to various degrees, interpreted, and used to develop further strategies for hydrocarbon exploration and exploitation. Beside seismic data, the most common categories of data collected in the field through drilling are well logs, on which basis stratigraphic picks and markers are identified (as well as rock porosity and other properties), pressures measured during drill stem tests, and bottom hole temperatures.Samples of formation water, core plugs and rock chips are analysed in the laboratory for information regarding the water chemistry, rock properties like porosity and permeability, and organic content and degree of maturation.Most often, the various categories of data are examined in isolation, by discipline, in order to arrive at conclusions regarding basin characteristics. Conventional basin analysis is concerned mostly with th

1997-10-12

Bachu, S.

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