Description of a predictive PVT engine to estimate petroleum fluid properties and phase behavior from wireline formation tests in real-time. The algorithms are developed from a worldwide database of reservoir fluid properties, including geochemistry and PVT data (www.rfdbase.com). By combining geochemical representations of source rock type, thermal maturity and biodegradation with selected formation test tool measurements, PVT parameters can be predicted prior to the collection of physical samples.