In-Situ Density and Viscosity Measured by Wireline Formation Testers

O'Keefe, Michael; Godefroy, S.; Vasques, Ricardo; Agenes, Anne Marie; Weinheber, Peter; Jackson, Richard; Ardila, Mario; Wichers, Wicher Roelf; Daungkaen, Saifon; Santo, Ilaria De

doi:10.2523/110364-ms

Cited by 7 publications

(4 citation statements)

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“…Some of the new measurements such as in-situ GOR, pH [9] , density [10] , fluid composition [6] including CO2 [11] may help in differentiating small differences in fluid composition. This technique can complement the routine PVT sampling and analysis and help identification of compositional gradient [12] and compartmentalization [13] .…”

Section: Fluid Scanning Using Dfamentioning

confidence: 99%

Advanced Formation Testing and PVT Sampling in Deep Gas Condensate Reservoir: Case Study from Malaysia

et al. 2009

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TX 75083-3836, U.S.A., fax +1-972-952-9435. AbstractDownhole sampling in gas condensate reservoir is well known to be challenging due to the nature of near critical fluids. Reservoir fluid properties can change dramatically with slight changes in reservoir pressure and temperature. As a result, accurate and representative PVT data are essential for reservoir fluid modeling and field development planning but difficult to obtain using conventional sampling techniques. This paper presents the first successful downhole gas condensate sampling in a high pressure gas condensate field, offshore East Malaysia. Samples collected from the previous surface tests showed large variation in Condensate Gas Ratio (CGR) from 50 to 200 stb/mmscf. This resulted in large uncertainty in the dew point pressure, condensate yield, well productivity, and reservoir fluid type. There was strong need to acquire high quality downhole samples to reduce these uncertainties, which can potentially affect the entire field development plan. Through the use of new technology and an integrated team approach, it was possible to take representative single phase fluid sample using controlled drawdown and real time fluid analysis of downhole sample.There were several key challenges in this operation. The team had to take single phase gas sample, with minimum contamination in a High pressure High temperature (HPHT) well drilled with Oil Based Mud (OBM), station time had to be as short as possible to avoid tool getting stuck, and have an initial estimate of dew point pressure and Gas Oil ratio (GOR) from downhole measurements. This was achieved using real time data monitoring and control of the entire wellsite operation from PETRONAS Carigali office. The latest downhole fluid identification tool was used along with focused sampling to minimize OBM contamination. This paper will highlight the effective use of various elements of new technology and team work.Fluid density measurement was found useful in answering some of the questions. It allowed comparison with optical fluid analyzer to provide an improved fluid identification. It also allowed to optimize the number of pretests and hence reduce the rig time and cost. By measuring the change in fluid density during clean up, the in-situ density tool also complemented other spectrometer based optical analyzers in determining the contamination level during sampling process.In this complex gas reservoir, there were potential reservoir compartments of different gas composition. Fluid samples from different zones confirmed the presence of such compartmentalization. The deeper zones showed much leaner gas composition compared to the shallower intervals. The knowledge of in-situ dew point pressure from downhole fluid analyzer was used to ensure a single phase gas sample during wireline sampling. This information was later used to design a well test to keep flowing bottom hole pressure above dew point pressure and thus obtain representative surface fluid samples. This paper demonstrates how a proper job planning, r...

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Section: Fluid Scanning Using Dfamentioning

confidence: 99%

Advanced Formation Testing and PVT Sampling in Deep Gas Condensate Reservoir: Case Study from Malaysia

et al. 2009

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“…(O'Keefe et al 2007) This sensor measures the density of the fluid by the vibration of a mechanical resonator in the flowline. (O'Keefe et al 2007) This sensor measures the density of the fluid by the vibration of a mechanical resonator in the flowline.…”

Section: Density -Viscosity (Dv) Sensormentioning

confidence: 99%

“…We take advantage of recent advances of NMR and WFT technology, namely 4D NMR logging (Heaton et al 2007) and in-situ fluid analyzer, oil density-viscosity (DV) measurement (O'Keefe et al 2007) to show, in many cases, NMR can be of great help to WFT measurements. In return, WFT measurements can be used to calibrate NMR fluid properties logs.…”

Section: Introductionmentioning

confidence: 99%

Using the Continuous NMR Fluid Properties Scan To Optimize Sampling With Wireline Formation Testers

et al. 2008

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One of the most important objectives of fluid sampling using wireline formation testers (WFT) is to ensure that representative samples of the different fluids encountered in the formation are obtained. Usually the wireline or LWD petrophysical logs will guide the sample acquisition program. This typically means that resistivity and nuclear logs are used to infer basic fluid types, caliper log is used to verify that the borehole is suitable for sampling, and NMR logs are used to gauge if permeability is sufficient for a sample to be taken. However these logs are not able to capture variations in the hydrocarbon column to allow the operator to ensure that all representative fluids are sampled. The most important information, a continuous fluids type and property log, is still not widely used in the industry.Modern NMR logging tools can deliver -in addition to conventional porosity and permeability information -a continuous fluid log of oil, gas, water and OBM filtrate (OBMF) at multiple depths of investigation. The radial fluid profiling allows discrimination of OBMF versus native oil. Additionally, within the hydrocarbon column the NMR measurements can be used to provide continuous logs of oil viscosity and gas-oil ratio (GOR). With this information acquired before the sampling operation, it is easier to ensure that a full suite of representative samples are acquired and that we do not indulge in needless over sampling. When NMR data is acquired after the sampling operation, the continuous logs of viscosity and GOR can be calibrated with WFT data to provide fluid information in places where WFT did not sample.

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“…However, laboratory processing for viscosity measurements usually take quite long, and a result, this lengthy time causes a delay in applying correct viscosity values to reservoir engineering calculations such as well producibility and reserve estimation. 2 shows five case studies on the application of downhole density and viscosity measurement at reservoir condition using a wireline formation tester. Traditionally, pressure gradients are used to evaluate fluid density, fluid contacts and layer connectivity in exploration wells.…”

Section: Introductionmentioning

confidence: 99%

Applications of Downhole In-Situ Reservoir Fluid Properties in Interval Pressure Transient Test

et al. 2013

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Pressure transient analysis has been known as an important tool to properly characterize a reservoir. The scales of measurement for different testing methods depend mainly on their radius of investigation, i.e. how far pressure changes/disturbance can be seen into reservoirs. In a large reservoir, a full scale testing method such as a Drill Stem Test (DST) is required to test enough reservoir volume for flow assurance purposes. To test for the reservoir extent, a production test is required to reach reservoir boundaries.In recent years, there have been tremendous developments for short period testing methods. The Formation Tester (FT) is one of the tools that are used to evaluate reservoir fluid properties and acquire pressure transient data from both dual packer and single probe configurations. With the current Downhole Fluid Analyzer (DFA) technology, reservoir fluid properties such as composition, Gas-Oil-Ratio (GOR), in-situ density, and viscosity can be obtained in real time. These insitu fluid properties can be used to analyze pressure transient data for reservoir permeability, skin factor, and reservoir heterogeneity; and as a result, the DFA serve to push IPTT applications to another step forward. This paper will specifically focus on the application of DFA for IPTT purposes and also a continuation of several published papers which discussed the use of different scales of pressure transient data. The results from this paper will mainly focus on the use of single probe and dual packer IPTT to obtain reservoir properties in thinly bedded reservoirs with waxy crudes from the South East Asia region. The viscosity variation from oil based mud filtrate to reservoir fluid during the pump-out and its effect on the pressure derivative will be discussed using actual examples to demonstrate this point.The end results may contradict traditional testing methods on the use of virgin reservoir fluid properties for pressure transient analysis. Hopefully, this paper might open another option when FT is deployed together with the current DFA tool for quick and effective reservoir evaluation in thinly bedded reservoirs which are often encountered in many parts of the world. TX 75083-3836, U.S.A., fax +1-972-952-9435

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In-Situ Density and Viscosity Measured by Wireline Formation Testers

Cited by 7 publications

References 0 publications

Advanced Formation Testing and PVT Sampling in Deep Gas Condensate Reservoir: Case Study from Malaysia

Advanced Formation Testing and PVT Sampling in Deep Gas Condensate Reservoir: Case Study from Malaysia

Using the Continuous NMR Fluid Properties Scan To Optimize Sampling With Wireline Formation Testers

Applications of Downhole In-Situ Reservoir Fluid Properties in Interval Pressure Transient Test

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