摘要:
The invention provides a method for determining phase transition pressure of downhole retrograde condensate. An OBM-contamination value is produced from a time-series of fluorescence values produced by measuring fluorescence emitted from a single-phase flow of OBM-contaminated formation fluid in a downhole cell during a cycle of time. The pressure of fluid in the cell is set at a transition boundary by incrementing drawdown pressure and monitoring the presence or absence of a phase transition. An apparent phase transition pressure value associated with the cycle of time is produced by setting apparent phase transition pressure value equal to cell pressure. This process is repeated for several cycles of time to produce a number of pairs of OBM-contamination value and apparent phase transition pressure value as OBM-contamination decreases over time. The value of phase transition pressure is determined by extrapolating from a representation of apparent phase transition pressure values versus OBM-contamination values.
摘要:
Methods and apparatus for investigating a hydrocarbon bearing geological formation traversed by a borehole are disclosed. A borehole tool is used to acquire a sample of fluid in the formation. Compositional analysis of the fluid sample is conducted to provide a determination of the composition of the sample. The sample composition is then related to a model of the thermodynamic behavior of the fluid; i.e., the mass fractions of the fluid components are used as inputs to an equation of state (EOS) to predict the phase behavior of the fluid.
摘要:
A method for estimating properties of fluids in rock formations at selected locations within a geologic basin includes generating an initial model of the basin. The model includes as output spatial distribution of a rock formation mineral composition, rock formation porosity and composition of fluids in the rock formation porosity. An initial estimate of fluid composition is generated for a rock formation, and a sample of fluid is extracted from pore spaces of the rock formation. Composition of the fluid sample is analyzed from within, and the initial model of the basin is adjusted to substantially match the analyzed fluid composition. The adjusted model is used to generate an initial estimate of fluid composition.
摘要:
A method of assuring the collection of reliable and quality fluid sample includes the steps of acquiring a fluid sample at a point of acquisition, analyzing physical and chemical properties of the fluid sample at the point of acquisition; recording the point of acquisition sample properties in an electronic database archive, analyzing physical and chemical properties of the fluid sample at a location remote from the point of acquisition, recording the remote location sample properties in the archive, validating the fluid sample through comparison of the point of acquisition sample properties and the remote location sample properties and recording the validated sample properties in the archive.
摘要:
Formation fluid data based on measurements taken downhole under natural conditions is utilized to help identify reservoir compartments. A geological model of the reservoir including expected pressure and temperature conditions is integrated with a predicted fluid model fitted to measured composition and PVT data on reservoir fluid samples or representative analog. Synthetic downhole fluid analysis (DFA) logs created from the predictive fluid model can be displayed along the proposed borehole trajectory by geological modeling software prior to data acquisition. During a downhole fluid sampling operation, actual measurements can be displayed next to the predicted logs. If agreement exists between the predicted and measured fluid samples, the geologic and fluid models are validated. However, if there is a discrepancy between the predicted and measured fluid samples, the geological model and the fluid model need to be re-analyzed, e.g., to identify reservoir fluid compartments. A quantitative comparative analysis of the sampled fluids can be performed against other samples in the same borehole or in different boreholes in the field or region to calculate the statistical similarity of the fluids, and thus the possible connectivity between two or more reservoir regions.
摘要:
A marking system and method for a well site sample is provided. The system includes a container for collecting the well site sample, a marker applied to the container and a scanner adapted to read the marker. Data may be uploaded to and/or downloaded from the marker.
摘要:
A method for estimating properties of fluids in rock formations at selected locations within a geologic basin includes generating an initial model of the basin. The model includes as output spatial distribution of at least rock formation mineral composition, rock formation porosity and composition of fluids in the rock formation porosity. An initial estimate of fluid composition is generated for at least one rock formation at at least one selected location within the basin. A sample of fluid is extracted from pore spaces of the at least one rock formation from within a wellbore drilled therethrough. Composition of the fluid sample is analyzed from within the wellbore. The initial model of the basin is adjusted such that model predictions substantially match the analyzed fluid composition. The adjusted model is used to generate an initial estimate of fluid composition at at least one additional geodetic location within the basin.
摘要:
A method for characterizing formation fluid using flowline viscosity and density data in an oil-based mud environment includes: making an initial estimate of the density and viscosity of the individual components of the sampled fluid; measuring the volume fractions, density, and viscosity of the total mixture of formation fluid; computing the density and viscosity of the total mixture using the estimate and the measured volume fractions; comparing the computed values with the measured values; and updating the estimate based on the comparison until convergence. The process is repeated as additional data are acquired until the converged computed values differ only by an acceptable amount.
摘要:
Methods of assuring that a representative formation and/or fluid sample of a subterranean reservoir is obtained are provided. One method of validating a reservoir fluid sample obtained from a wellbore includes the steps of acquiring a reservoir fluid sample in the wellbore; measuring a property of the fluid sample downhole with a technique to obtain a measured downhole fluid property; replicating the measuring technique used to obtain the measured downhole fluid property to obtain at a remote location from the wellbore with a technique to obtain at least one measured remote location fluid property; validating the fluid sample through comparison of the measured downhole fluid property and the at least one measured remote location fluid property.