Downhole PVT fluid samples are primarily acquired by the customer directly from oil and gas wells located offshore. The sampling tools are often conveyed on wireline and activated from the surface to capture representative fluids. Advanced single-phase chambers keep the fluids above reservoir pressure, despite cooling during transfer, helping to avoid pressure drop induced asphaltene precipitation.
Once received in our laboratory, the collected fluid samples are restored via agitation at the original reservoir pressure and temperature. Initial validation checks provide basic PVT properties and a measure of oil-based mud contamination common to openhole samples. More in-depth analyses provide additional information about specific hydrocarbon behaviors. Refer to PVT Laboratory Testing – Best Practices.
Applications
PVT analysis is the scientific process used to determine phase behavior and fluid properties of oil and gas samples from your well—both in the reservoir (downhole) and at the surface. This analytic testing information gives you a better understanding of your hydrocarbon reserves, so you can apply the most cost-effective extraction methods to optimize production. Refer to PVT Lab Testing – Best Practices.
Data in Context
GeoMark maintains a database of thousands of offshore PVT reports (www.rfdbase.com) for easy reference. This data provides excellent context when considering the behavior of new fluids. For example, fluids with complex geochemical sourcing usually have different PVT properties than those with more straightforward pedigrees.
FAQ
Q. Are the captured samples reliable?
A. This question is answered by the opening pressures and initial flash validations. Opening pressures should correspond to the reported pressures from the field. The flash validations should show consistency between fluids from the same depth and, ideally, low levels of oil-based mud contamination.
Q. How do the fluid properties compare to nearby wells?
A. This question is best addressed by accessing GeoMark’s Rock and Fluid Database (www.rfdbase.com).
Q. Do the fluid properties make sense?
A. GeoMark offers a substantial advantage by incorporating geochemical data into our PVT studies. Geochemical markers help identify certain characteristics, like fluid thermal maturity and mixing, which are key drivers of eventual PVT behavior.