Schlumberger Technology Corporation

Soraya Sofia Betancourt

Oliver Clinton Mullins

Chengli Dong

Francois Xavier Dubost

Julian J Pop

Christopher Del Campo

Peter S Hegeman

Bhavani Raghuraman

Go Fujisawa

Toru Terabayashi

Michael O'Keefe

Anthony Goodwin

Terizhandur S Ramakrishnan

Tsutomu Yamate

Cosan Ayan

Ricardo Vasques

Ronald E G Van Hal

Ahmed Hammami

Lennox Reid

John Allan Nighswander

Takeaki Nakayama

Hideki Kinjo

Akihito Chikenji

Hani Elshahawi

Yi-Qiao Song

Li Jiang

Kentaro Indo

Andrew Emil Pomerantz

Andrew L Kurkjian

Soumyajit Mandal

Abdel Kharrat

Ashley C Kishino

Elizabeth B Dussan V

John Ratulowski

Gale Hyslip Gustavson

A Ballard Andrews

Moin Muhammad

Erwan Olliero

Armin Kauerauf

Saad Bargach

Youxiang (Julian) Zuo

Jinglin Gao

James J Dunlap

Syriac George Mathews

Tara Davies

Raymond G Kennedy

Peter S Hageman

Methods are disclosed for processing, in real-time, pressure data acquired with a formation tester during a pretest to quickly establish the quality of the measurement being conducted. The methods can optimize pressure measurement operations by assessing whether it is desirable or not to wait for the formation tester flowline pressure to equilibrate to the sandface pressure. In one embodiment, a determination is made as to whether the pretest succeeded in establishing hydraulic communication between the formation and the flowline by comparing the pressure signal with a simulation of the pressure behavior corresponding to a false buildup during a dry test. In another embodiment, a determination is made as to whether the pretest succeeded in isolating the tool flowline and the formation from the wellbore by using the pressure signal to estimate the sandface pressure during buildup over time, and to compare the estimated sandface pressure signal with the borehole pressure.

Methods for analyzing formation tester pretest data

A formation fluid sample is analyzed using NMR spectroscopy to obtain a NMR spectrum. The NMR spectrum is then analyzed to find evidence of the amount of olefins present in the sample. The amount of olefins present in the sample can then be correlated to the level of contamination of the sample. In one embodiment, aH chemical shift of between substantially 4.5 and 6 ppm is used to identify olefins present in the sample. In another embodiment, aH chemical shift of substantially 1.9 to 2.1 ppm is used to identify olefins present in the sample. The NMR spectral equipment can be located uphole or downhole.

Method and apparatus for determining mud contamination of formation fluid

A formation fluid sampling tool is provided with reactants which are carried downhole and which are combined in order to generate heat energy which is applied to the formation adjacent the borehole. By applying heat energy to the formation, the formation fluids are heated, thereby increasing mobility, and fluid sampling is expedited.

Formation fluid sampling tools and methods utilizing chemical heating

A downhole characterization apparatus for formation fluids is provided. The apparatus comprises a downhole tool including a flowline for flowing the formation fluids capable of isolating a quantity of the formation fluids in a portion thereof; and a pump unit for depressurizing the isolated formation fluids; and a measurement controller which controls the downhole tool. The measurement controller includes a rough value estimation unit which estimates a rough value of the bubble point pressure of the formation fluids; and a speed controller which controls the depressurizing speed of the pump unit such that the isolated formation fluids are depressurized at a first speed to a certain pressure which is a predetermined value higher than said estimated rough value, and the isolated fluids are depressurized at a second speed which is slower than said first speed in order to measure a precise value of the bubble point pressure.

Method of downhole characterization of formation fluids, measurement controller for downhole characterization of formation fluids, and apparatus for downhole characterization of formation fluids

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.

Method for integrating reservoir charge modeling and downhole fluid analysis

Methods and apparatus to form a well are disclosed. An example method involves determining a reservoir fluid map associated with at least a portion of a reservoir. The first fluid map has first fluid composition data associated therewith. The example method also involves measuring a formation fluid and determining a second fluid composition data based on the measurement. The second fluid composition data is compared with the first fluid composition data associated with the reservoir fluid map, and a well trajectory is adjusted based on the comparison.

Methods and apparatus to form a well

A method and system for characterizing asphaltene gradients of a reservoir of interest and analyzing properties of the reservoir of interest based upon such asphaltene gradients. The analysis employs a correlation that relates insoluble asphaltene concentration to spectrophotometry measurement data measured at depth.

Methods and apparatus for analysis of downhole asphaltene gradients and applications thereof

A method of downhole characterization of formation fluids is provided. The method includes: estimating a rough value of the bubble point pressure of the formation fluids; depressurizing the formation fluids at a first speed to a certain pressure which is a predetermined value higher than the estimated rough value while the formation fluids are isolated in a portion of the flowline; and depressurizing the isolated fluids at a second speed which is slower than the first speed in order to measure a precise value of the bubble point pressure.

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.

Reservoir sample chain-of-custody

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.

Marking system and method

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.

Fluids chain-of-custody

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.

Formation fluid characterization using flowline viscosity and density data an oil-based mud environment

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.

Methods and apparatus for the downhole characterization of formation fluids

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.

Determining phase transition pressure of downhole retrograde condensate

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Cambridge, MA, United States of America

Soraya Sofia Betancourt