Relating to fossil energy resource characterization, research, technology development, and technology transfer

Geological, geophysical and petroleum engineering aspects of oil recovery from low-permeability reservoirs have been studied over the past three years. Significant advances were made in using Formation Microscanner Surveys (FMS) data to extrapolate fracture orientation, abundance, and spacing from the outcrop to the subsurface. Highly fractured zones within the reservoir can be detected, thus the fracture stratigraphy defined. Multi-component,vertical-seismic profile (VSP), shear wave data were used to improve the detection of fractures. A balancing scheme was developed to improve the geophysical detection of fractures based on balanced source magnitudes and geophone couplings. Resistivity logs can be used to identify the zone of immature organic material, the zone of storage where oil is generated but held in the matrix and the zone of migration whee oil is expelled from the rock to fractures. Natural fractures can be detected in many wells by the response of density logs in combination with gamma-ray, resistivity, and sonic logs. Theoretical studies and analysis of daily production data, from field case histories, have shown the utility of the Chef Type Curves to derive reservoir character from production test data. This information is ordinarily determined from transient pressure data. Laboratory displacement as well as MI and CT studies show that the carbonated water imbibition oil displacement process significantly accelerates and increases recovery from saturated, low-permeability core material. The created gas drive, combined with oil shrinkage significantly increased oil recovery. A cyclic-carbonated-water-imbibition process improves oil recovery. A semi-analytical model (MOD) and a 3-dimensional, 3-phase, dual-porosity, compositional simulator (COMAS) were developed to describe the imbibition carbonated waterflood performance. MOD model is capable of computing the oil recovery and saturation profiles for oil/water viscosity ratios other than one