Geologic methods in supplemental hydrocarbon recovery projects

Geologic studies undertaken for supplemental recovery projects usually have 3 principal objectives: (1) determining the vertical and lateral limits of reservoir units; (2) establishing the thickness distribution patterns of each unit; and (3) developing the 3-dimensional distribution of porosity, permeability, and hydrocarbon saturation properties within each reservoir unit. The methods for accomplishing these objectives may utilize data from various sources (seismic surveys, cores or cuttings, core analysis, log analysis, well testing and production records) to characterize the reservoir geology. By combining technology developed both by geologists and engineers, it is possible to improve the prediction of waterflood frontal advance, locate areas for infill drilling, and identify zones where coning will occur. Reservoir geology characteristics are usually influenced by a combination of 2 geologic phenomena; depositional processes and post-depositional events. In many reservoirs the level, range and distribution of reservoir parameter values can be directly related to the manner in which the reservoir facies was deposited; with slight adjustment, the 4-step procedure is still valid.