PVT Express

Delivering early fluidanalysis data

Monophasic sample

Flash to atmospheric conditions

PVT Expertprediction

REPORT

Reservoir fluidmolecular composition

LiquidGas

GC analysis Density

ViscosityMolecularcomposition

GC analysis

Molecularcomposition

GOR

Saturation pressure determination at bottomhole temperature

Physical properties predictions

Physical samplePhysical measurementCalculated data

SMP-5916 ©Schlumberger

June 2003 *Mark of Schlumberger

www.slb.com/oilfield

Case historyThe PVT Express system has been testedin the world’s harshest environments,from the Middle East deserts to offshoreNewfoundland, providing early PVT datafor critical wellsite decisions.

In a well offshore Newfoundland,hydrocarbon samples were vital in char-acterizing the reservoir fluid and as inputfor the formulation of field developmentplans. It was critical that uncontaminatedsamples be recovered without undergoingphase changes. In addition, the measuredfluid properties of the recovered MDTsamples were to be compared withknown properties of samples collectedfrom the exploratory well. If the fluidproperties were similar, a costly well-test-ing program could be avoided.

The PVT Express system delivered twocomplete PVT studies within hours ofrecovering the MDT samples at the sur-face. These results matched the knownPVT properties from the exploratory well.Running a full well test was deemedunnecessary, which saved a significant

amount of money.In another well in Oman, the objectives

were to ensure representative gas conden-sate bottomhole samples were collectedduring a well test and to monitor surfacegas and liquid composition to achieve sta-bilized flow.

The first set of bottomhole gas conden-sate samples analyzed in the PVT Expresslaboratory exhibited a measured dew-point close to the flowing bottomholepressure, indicating the samples werenonrepresentative. Consequently, the wellwas produced on a lower choke, and asecond set of bottomhole samples wascollected. The dewpoint measured onthis set of bottomhole samples was wellbelow the flowing bottomhole pressure,indicating the well was producingmonophasically into the wellbore and rep-resentative bottomhole samples werebeing recovered. Two gas condensate con-stant-volume-depletion PVT studies werecompleted at the wellsite using the PVTExpress system in addition to 15 surfacesample compositional studies.

PVT Express FvF Prediction versus Measured Laboratory FvF Data

Oil formation volume factor

Pressure

Laboratory FvF

PVT Express FvF

PVT Express Viscosity Prediction versus Measured Laboratory Viscosity Data

Viscosity

Pressure

Laboratory measured viscosities

PVT Express viscosities

Graph comparing PVT Express-predicted oil viscosities with measured laboratory oil viscosities.

Graph comparing PVT Express-predicted formation volume factors (FvF) with measured laboratory formation volume factors.

PVT Express analytical flow diagram.

Measured Fluid Properties

Black Oil Gas Condensate

Bubblepoint pressure Dewpoint pressureLive oil compressibility Fluid density at dewpoint pressureFluid density at bubblepoint pressure Flash gas molecular mass† (specific gravity)Flash GOR Flash GORStock tank oil density (API gravity) Condensate density (API gravity)Flash gas composition† (C12+) Flash gas composition (C12+)Stock tank oil composition (C36+) Stock tank oil composition (C36+)Reservoir fluid composition (C36+) Reservoir fluid composition (C36+)Flash gas molecular mass† (specific gravity) Z factor at dewpoint pressure†

Stock tank oil molecular mass† Stock tank liquid molecular mass†

Reservoir oil molecular mass† Reservoir fluid molecular mass†

Reservoir oil viscosity (not standard equipment—optional)

Predicted PVT Properties

Constant composition expansion Constant composition expansion at reservoir temperature at reservoir temperature

-Oil compressibility -Single- and two-phase relative volume-Oil relative volume -Single- and two-phase fluid compressibility

-Retrograde liquid depositDifferential liberation at Constant volume depletion at reservoir temperature reservoir temperature

-Oil formation volume factor -Cumulative produced fluid to depletion-Solution GOR -Single- and two-phase fluid Z factor-Oil density -Retrograde liquid deposit-Oil viscosity -Produced gas gravity (molar mass)-Produced gas gravity (molar mass)-Produced gas Z factor

Separator test at specified separator pressure and temperature

-Oil formation volume factor-Separator shrinkage factor-Tank, separator, and total GOR-Separator oil density-Stock tank oil density (API gravity)

†Based on industry standards

Applications■ Pressure-volume-temperature

(PVT) data collection for proj-ects in which early delivery ofresults is critical

■ Projects in locations in whichaccess to PVT laboratories islimited by geographical locationand/or local shipping regulations

■ Validation of sample quality dur-ing wireline formation testing,drillstem testing, or productiontesting operations

■ Compositional monitoring ofseparator gas or reservoir fluidsamples, providing informationto optimize gas condensate fluidsampling

Benefits■ Eliminates risks associated with

operation and transportation ofmercury PVT laboratory equip-ment

■ Allows rapid mobilization to anygeographic location

■ Delivers PVT results within 8hours

■ Enables informed decisions during logging and well-testingoperations

■ Delivers high-quality PVT data ona complete range of hydrocarbonfluids (heavy oil to gas conden-sate)

■ Reduces sample shipping andstorage costs

Features■ Measurement techniques based

on proven PVT laboratory proce-dures

■ Very small volume of samplerequired for full PVT study (lessthan 50 cm3)

■ Included fiber-optic sensor tomeasure saturation pressure ofgas condensates and volatile oils

■ Modular, rugged constructionfor transportation by road, sea,or air.

■ Patented helium ionizationdetector used in dual gas chromatograph (GC) [gas C12+,liquid C36+]

■ Advanced hardware and soft-ware technology that providesaccurate measured and pre-dicted PVT data

■ Accurate testing for oil-basemud contamination in samplescollected with wireline forma-tion test tools

Advanced mobile fluid analysis serviceThe Schlumberger PVT Express* service isbased on a revolutionary hardware and soft-ware platform that can deliver comprehen-sive fluid analysis data in a matter of hours.

This system has many advantages overtraditional PVT equipment and services. Theutilization of mercury-free technology elimi-nates the inherent health, safety, and envi-ronmental (HSE) risks associated with theuse and transportation of mercury. Modular,rugged construction facilitates transporta-tion by road, sea, and air to any geographiclocation, including a local operations baseor the wellsite itself. The mobility and flexi-bility of the PVT Express system allowresults to be delivered in hours rather thanweeks or months, in part because of theelimination of long sample transportationwait times.

This system has applications in explo-ration, development, and production envi-ronments. Acquiring sample quality dataand measuring reservoir fluid propertiesduring wireline formation testing operationsmean our customers do not have to waitweeks or months to determine if the objec-tives of the sampling operation wereachieved. Analysis at the wellsite enablesdecisions about additional wireline forma-tion testing or drillstem testing operations.Similarly, during drillstem testing operationsthe PVT Express service can be used toensure that representative samples havebeen collected before leaving the well.

Fluid properties generated by the servicecan be used to set up the PhaseWatcher*multiphase well production monitoringequipment and to generate data for produc-tion optimization strategies.

With the current emphasis on fast-trackfield development, having swift results iscritical. Utilizing the PVT Express service at the wellsite or a local support base canovercome the problem of data deliverydelays.

HardwareUsing a conventional or single-phase samplecollected by the MDT* Modular FormationDynamics Tester or the CHDT* Cased HoleDynamics Tester, the PVT Express systememploys advanced technology to measuresome properties and predict others.

The PVT Express system features a high-pressure PVT cell that measures the satura-tion pressure of the reservoir fluid atreservoir temperature. Accurate measure-ment of bubblepoint and dewpoint pressureis made possible by optical signal technol-ogy that measures the first bubble of gas lib-erated from oil and the first traces ofcondensable liquid in a gas during constanttemperature expansion from reservoir pres-sure.

An additional advantage of the PVTExpress high-pressure cell is the ability toproduce a comprehensive fluid analysisreport with less than 50 cm3 of single-phase

A PVT Express specialist completes a reservoir fluid flash analysis. Laboratory equipment shown includes a PVT cell,a temperature-controlled gas/oil ratio (GOR) liquid trap, an atmospheric liquid densitometer, and a viscometer.

reservoir fluid. This is significantly less volume than traditional mercury PVTequipment requires.

A proprietary dual chromatograph (oiland gas), featuring patented helium ion-ization detectors, is used to deliver com-positional data. Flame ionizationdetectors typically utilize hydrogen gas.Helium ionization technology eliminatesthe requirement to use hydrogen, thusenhancing the safety and mobility of theservice.

All data measured by the high-pressurecell are displayed and stored in real timeby a digital interface module. In additionto interpreting and reporting the meas-ured data, this interface module also linksto the Schlumberger PVT Expert* predic-tion model.

SoftwareThe PVT Expert system is an operator-independent, multidimensional predictionmodel that delivers instant and reliablevolumetric phase behavior fluid proper-ties from a specific set of measured data.In contrast to equation-of-state predictionmodels, the PVT Expert system is ideallysuited to wellsite operations, requiring notime-consuming tuning operations. Inaddition to providing rapid fluid analysisdata, this prediction model includes aquality assurance tool that providesinstant evaluation of the quality of thefluid property predictions.

Data quality management processTo ensure the quality of the data reportedby the PVT Express service, it will be sup-ported by Schlumberger fluid analysisexperts strategically located in a globalnetwork of fluid analysis centers and lab-oratories. An integral and key feature ofthe PVT Express service is the data qual-ity-control service provided by our analy-sis experts. Customized to suit thespecific needs of the project, the qualitycontrol service will range from real-timesupport of wellsite operations to reviewof the report before delivery to the cus-tomer.

PVT Express delivers early fluid property results from openhole, cased hole, or surface samples. Data qualityis assured by a global network of fluid analysis centers.

POCKET

Applications■ Pressure-volume-temperature

(PVT) data collection for proj-ects in which early delivery ofresults is critical

■ Projects in locations in whichaccess to PVT laboratories islimited by geographical locationand/or local shipping regulations

■ Validation of sample quality dur-ing wireline formation testing,drillstem testing, or productiontesting operations

■ Compositional monitoring ofseparator gas or reservoir fluidsamples, providing informationto optimize gas condensate fluidsampling

Benefits■ Eliminates risks associated with

operation and transportation ofmercury PVT laboratory equip-ment

■ Allows rapid mobilization to anygeographic location

■ Delivers PVT results within 8hours

■ Enables informed decisions during logging and well-testingoperations

■ Delivers high-quality PVT data ona complete range of hydrocarbonfluids (heavy oil to gas conden-sate)

■ Reduces sample shipping andstorage costs

Features■ Measurement techniques based

on proven PVT laboratory proce-dures

■ Very small volume of samplerequired for full PVT study (lessthan 50 cm3)

■ Included fiber-optic sensor tomeasure saturation pressure ofgas condensates and volatile oils

■ Modular, rugged constructionfor transportation by road, sea,or air.

■ Patented helium ionizationdetector used in dual gas chromatograph (GC) [gas C12+,liquid C36+]

■ Advanced hardware and soft-ware technology that providesaccurate measured and pre-dicted PVT data

■ Accurate testing for oil-basemud contamination in samplescollected with wireline forma-tion test tools

Advanced mobile fluid analysis serviceThe Schlumberger PVT Express* service isbased on a revolutionary hardware and soft-ware platform that can deliver comprehen-sive fluid analysis data in a matter of hours.

This system has many advantages overtraditional PVT equipment and services. Theutilization of mercury-free technology elimi-nates the inherent health, safety, and envi-ronmental (HSE) risks associated with theuse and transportation of mercury. Modular,rugged construction facilitates transporta-tion by road, sea, and air to any geographiclocation, including a local operations baseor the wellsite itself. The mobility and flexi-bility of the PVT Express system allowresults to be delivered in hours rather thanweeks or months, in part because of theelimination of long sample transportationwait times.

This system has applications in explo-ration, development, and production envi-ronments. Acquiring sample quality dataand measuring reservoir fluid propertiesduring wireline formation testing operationsmean our customers do not have to waitweeks or months to determine if the objec-tives of the sampling operation wereachieved. Analysis at the wellsite enablesdecisions about additional wireline forma-tion testing or drillstem testing operations.Similarly, during drillstem testing operationsthe PVT Express service can be used toensure that representative samples havebeen collected before leaving the well.

Fluid properties generated by the servicecan be used to set up the PhaseWatcher*multiphase well production monitoringequipment and to generate data for produc-tion optimization strategies.

With the current emphasis on fast-trackfield development, having swift results iscritical. Utilizing the PVT Express service at the wellsite or a local support base canovercome the problem of data deliverydelays.

HardwareUsing a conventional or single-phase samplecollected by the MDT* Modular FormationDynamics Tester or the CHDT* Cased HoleDynamics Tester, the PVT Express systememploys advanced technology to measuresome properties and predict others.

The PVT Express system features a high-pressure PVT cell that measures the satura-tion pressure of the reservoir fluid atreservoir temperature. Accurate measure-ment of bubblepoint and dewpoint pressureis made possible by optical signal technol-ogy that measures the first bubble of gas lib-erated from oil and the first traces ofcondensable liquid in a gas during constanttemperature expansion from reservoir pres-sure.

An additional advantage of the PVTExpress high-pressure cell is the ability toproduce a comprehensive fluid analysisreport with less than 50 cm3 of single-phase

A PVT Express specialist completes a reservoir fluid flash analysis. Laboratory equipment shown includes a PVT cell,a temperature-controlled gas/oil ratio (GOR) liquid trap, an atmospheric liquid densitometer, and a viscometer.

reservoir fluid. This is significantly less volume than traditional mercury PVTequipment requires.

A proprietary dual chromatograph (oiland gas), featuring patented helium ion-ization detectors, is used to deliver com-positional data. Flame ionizationdetectors typically utilize hydrogen gas.Helium ionization technology eliminatesthe requirement to use hydrogen, thusenhancing the safety and mobility of theservice.

All data measured by the high-pressurecell are displayed and stored in real timeby a digital interface module. In additionto interpreting and reporting the meas-ured data, this interface module also linksto the Schlumberger PVT Expert* predic-tion model.

SoftwareThe PVT Expert system is an operator-independent, multidimensional predictionmodel that delivers instant and reliablevolumetric phase behavior fluid proper-ties from a specific set of measured data.In contrast to equation-of-state predictionmodels, the PVT Expert system is ideallysuited to wellsite operations, requiring notime-consuming tuning operations. Inaddition to providing rapid fluid analysisdata, this prediction model includes aquality assurance tool that providesinstant evaluation of the quality of thefluid property predictions.

Data quality management processTo ensure the quality of the data reportedby the PVT Express service, it will be sup-ported by Schlumberger fluid analysisexperts strategically located in a globalnetwork of fluid analysis centers and lab-oratories. An integral and key feature ofthe PVT Express service is the data qual-ity-control service provided by our analy-sis experts. Customized to suit thespecific needs of the project, the qualitycontrol service will range from real-timesupport of wellsite operations to reviewof the report before delivery to the cus-tomer.

PVT Express delivers early fluid property results from openhole, cased hole, or surface samples. Data qualityis assured by a global network of fluid analysis centers.

POCKET

PVT Express

Delivering early fluidanalysis data

Monophasic sample

Flash to atmospheric conditions

PVT Expertprediction

REPORT

Reservoir fluidmolecular composition

LiquidGas

GC analysis Density

ViscosityMolecularcomposition

GC analysis

Molecularcomposition

GOR

Saturation pressure determination at bottomhole temperature

Physical properties predictions

Physical samplePhysical measurementCalculated data

SMP-5916 ©Schlumberger

June 2003 *Mark of Schlumberger

www.slb.com/oilfield

Case historyThe PVT Express system has been testedin the world’s harshest environments,from the Middle East deserts to offshoreNewfoundland, providing early PVT datafor critical wellsite decisions.

In a well offshore Newfoundland,hydrocarbon samples were vital in char-acterizing the reservoir fluid and as inputfor the formulation of field developmentplans. It was critical that uncontaminatedsamples be recovered without undergoingphase changes. In addition, the measuredfluid properties of the recovered MDTsamples were to be compared withknown properties of samples collectedfrom the exploratory well. If the fluidproperties were similar, a costly well-test-ing program could be avoided.

The PVT Express system delivered twocomplete PVT studies within hours ofrecovering the MDT samples at the sur-face. These results matched the knownPVT properties from the exploratory well.Running a full well test was deemedunnecessary, which saved a significant

amount of money.In another well in Oman, the objectives

were to ensure representative gas conden-sate bottomhole samples were collectedduring a well test and to monitor surfacegas and liquid composition to achieve sta-bilized flow.

The first set of bottomhole gas conden-sate samples analyzed in the PVT Expresslaboratory exhibited a measured dew-point close to the flowing bottomholepressure, indicating the samples werenonrepresentative. Consequently, the wellwas produced on a lower choke, and asecond set of bottomhole samples wascollected. The dewpoint measured onthis set of bottomhole samples was wellbelow the flowing bottomhole pressure,indicating the well was producingmonophasically into the wellbore and rep-resentative bottomhole samples werebeing recovered. Two gas condensate con-stant-volume-depletion PVT studies werecompleted at the wellsite using the PVTExpress system in addition to 15 surfacesample compositional studies.

PVT Express FvF Prediction versus Measured Laboratory FvF Data

Oil formation volume factor

Pressure

Laboratory FvF

PVT Express FvF

PVT Express Viscosity Prediction versus Measured Laboratory Viscosity Data

Viscosity

Pressure

Laboratory measured viscosities

PVT Express viscosities

Graph comparing PVT Express-predicted oil viscosities with measured laboratory oil viscosities.

Graph comparing PVT Express-predicted formation volume factors (FvF) with measured laboratory formation volume factors.

PVT Express analytical flow diagram.

Measured Fluid Properties

Black Oil Gas Condensate

Bubblepoint pressure Dewpoint pressureLive oil compressibility Fluid density at dewpoint pressureFluid density at bubblepoint pressure Flash gas molecular mass† (specific gravity)Flash GOR Flash GORStock tank oil density (API gravity) Condensate density (API gravity)Flash gas composition† (C12+) Flash gas composition (C12+)Stock tank oil composition (C36+) Stock tank oil composition (C36+)Reservoir fluid composition (C36+) Reservoir fluid composition (C36+)Flash gas molecular mass† (specific gravity) Z factor at dewpoint pressure†

Stock tank oil molecular mass† Stock tank liquid molecular mass†

Reservoir oil molecular mass† Reservoir fluid molecular mass†

Reservoir oil viscosity (not standard equipment—optional)

Predicted PVT Properties

Constant composition expansion Constant composition expansion at reservoir temperature at reservoir temperature

-Oil compressibility -Single- and two-phase relative volume-Oil relative volume -Single- and two-phase fluid compressibility

-Retrograde liquid depositDifferential liberation at Constant volume depletion at reservoir temperature reservoir temperature

-Oil formation volume factor -Cumulative produced fluid to depletion-Solution GOR -Single- and two-phase fluid Z factor-Oil density -Retrograde liquid deposit-Oil viscosity -Produced gas gravity (molar mass)-Produced gas gravity (molar mass)-Produced gas Z factor

Separator test at specified separator pressure and temperature

-Oil formation volume factor-Separator shrinkage factor-Tank, separator, and total GOR-Separator oil density-Stock tank oil density (API gravity)

†Based on industry standards

PVT Express

Delivering early fluidanalysis data

Monophasic sample

Flash to atmospheric conditions

PVT Expertprediction

REPORT

Reservoir fluidmolecular composition

LiquidGas

GC analysis Density

ViscosityMolecularcomposition

GC analysis

Molecularcomposition

GOR

Saturation pressure determination at bottomhole temperature

Physical properties predictions

Physical samplePhysical measurementCalculated data

SMP-5916 ©Schlumberger

June 2003 *Mark of Schlumberger

www.slb.com/oilfield

Case historyThe PVT Express system has been testedin the world’s harshest environments,from the Middle East deserts to offshoreNewfoundland, providing early PVT datafor critical wellsite decisions.

In a well offshore Newfoundland,hydrocarbon samples were vital in char-acterizing the reservoir fluid and as inputfor the formulation of field developmentplans. It was critical that uncontaminatedsamples be recovered without undergoingphase changes. In addition, the measuredfluid properties of the recovered MDTsamples were to be compared withknown properties of samples collectedfrom the exploratory well. If the fluidproperties were similar, a costly well-test-ing program could be avoided.

The PVT Express system delivered twocomplete PVT studies within hours ofrecovering the MDT samples at the sur-face. These results matched the knownPVT properties from the exploratory well.Running a full well test was deemedunnecessary, which saved a significant

amount of money.In another well in Oman, the objectives

were to ensure representative gas conden-sate bottomhole samples were collectedduring a well test and to monitor surfacegas and liquid composition to achieve sta-bilized flow.

The first set of bottomhole gas conden-sate samples analyzed in the PVT Expresslaboratory exhibited a measured dew-point close to the flowing bottomholepressure, indicating the samples werenonrepresentative. Consequently, the wellwas produced on a lower choke, and asecond set of bottomhole samples wascollected. The dewpoint measured onthis set of bottomhole samples was wellbelow the flowing bottomhole pressure,indicating the well was producingmonophasically into the wellbore and rep-resentative bottomhole samples werebeing recovered. Two gas condensate con-stant-volume-depletion PVT studies werecompleted at the wellsite using the PVTExpress system in addition to 15 surfacesample compositional studies.

PVT Express FvF Prediction versus Measured Laboratory FvF Data

Oil formation volume factor

Pressure

Laboratory FvF

PVT Express FvF

PVT Express Viscosity Prediction versus Measured Laboratory Viscosity Data

Viscosity

Pressure

Laboratory measured viscosities

PVT Express viscosities

Graph comparing PVT Express-predicted oil viscosities with measured laboratory oil viscosities.

Graph comparing PVT Express-predicted formation volume factors (FvF) with measured laboratory formation volume factors.

PVT Express analytical flow diagram.

Measured Fluid Properties

Black Oil Gas Condensate

Bubblepoint pressure Dewpoint pressureLive oil compressibility Fluid density at dewpoint pressureFluid density at bubblepoint pressure Flash gas molecular mass† (specific gravity)Flash GOR Flash GORStock tank oil density (API gravity) Condensate density (API gravity)Flash gas composition† (C12+) Flash gas composition (C12+)Stock tank oil composition (C36+) Stock tank oil composition (C36+)Reservoir fluid composition (C36+) Reservoir fluid composition (C36+)Flash gas molecular mass† (specific gravity) Z factor at dewpoint pressure†

Stock tank oil molecular mass† Stock tank liquid molecular mass†

Reservoir oil molecular mass† Reservoir fluid molecular mass†

Reservoir oil viscosity (not standard equipment—optional)

Predicted PVT Properties

Constant composition expansion Constant composition expansion at reservoir temperature at reservoir temperature

-Oil compressibility -Single- and two-phase relative volume-Oil relative volume -Single- and two-phase fluid compressibility

-Retrograde liquid depositDifferential liberation at Constant volume depletion at reservoir temperature reservoir temperature

-Oil formation volume factor -Cumulative produced fluid to depletion-Solution GOR -Single- and two-phase fluid Z factor-Oil density -Retrograde liquid deposit-Oil viscosity -Produced gas gravity (molar mass)-Produced gas gravity (molar mass)-Produced gas Z factor

Separator test at specified separator pressure and temperature

-Oil formation volume factor-Separator shrinkage factor-Tank, separator, and total GOR-Separator oil density-Stock tank oil density (API gravity)

†Based on industry standards