Applications of Accurate In-Situ Fluid Analysis in the North Sea SPE 145643 Vladislav Achourov, Adriaan Gisolf, Schlumberger Andreas Kansy, RWE-Dea, Kåre Otto Eriksen, Statoil Michael O'Keefe, Thomas Pfeiffer, Schlumberger
Overview Introduction Downhole Fluid Analysis (DFA) In-Situ Fluid Analyzer Case Studies Conclusions
Downhole Fluid Analysis New Tech. for Res. Evaluation Dep pth (m) xx60 xx80 xx00 0.374 g/cc Pressure Gradients Composition (wt%) GOR Ch. 1 (scf/bbl) C2-C5 C1 C6+ water (OD) xx68.2m * 9000 01 0.1 0.599 g/cc xx75.1m 2500 0.7 xx85.6m 2100 0.8 xx00.0m 1800 1.4 xx06.3m 1500 2.0 xx20 0.982 g/cc 377 378 379 380 381 Compositionally graded Pressure (bar) reservoir
DFA Technology WFT Dual Spectrometers Grating (16 Channels) Filter * (20 Channels) Fluorescence* & Gas Detector DV-Rod** Resistivity** & spare DFA port IFA P/T Hydrocarbon composition: C1, C2, C3-5, C6+ Carbon Dioxide CO2 Gas-Oil Ratio (GOR) Formation water ph Asphaltene gradient (Colour) OBM Contamination Automatic LQC (detection of mud-coated sensor) Single Phase Assurance for sampling Dew Precipitation (condensate) & Gas detection Near-critical Fluid ID (volatile oil or condensate) Flowline Pressure and Temp (EOS model) InSitu Density** Fluid Resistivity** (for Dual Packer sampling) Expansion ports for DFA sensors (Viscosity)
DFA Technology WFT Dual Spectrometers Grating (16 Channels) Filter * (20 Channels) Fluorescence* & Gas Detector InSitu Density** Resistivity** InSitu Viscosity IFA Hydrocarbon composition: C1, C2, C3-5, C6+ Carbon Dioxide CO2 Gas-Oil Ratio (GOR) Formation water ph Asphaltene gradient (Colour) OBM Contamination Automatic LQC (detection of mud-coated sensor) Single Phase Assurance for sampling P/T Dew Precipitation (condensate) & Gas detection Near-critical Fluid ID (volatile oil or condensate) Flowline Pressure and Temp (EOS model) InSitu Density** Fluid Resistivity** (for Dual Packer sampling) Expansion ports for DFA sensors (Viscosity) ** Also available on Quicksilver Sampling Probe
Composition From Spectroscopy OD 0.25 CFA 0.20 0.15 0.10 PD array Mirror 0.05 OD 0.6 IFA - Grating Spectrometer 0.00 OD 0.6 Wavelength (nm) Research-grade Laboratory Spectrometer Grating 0.4 0.2 0.2 1st and 2nd DFA generation Filter Spectrometer employ 0.0 Wavelength (nm) Optical Dens 0.4 10 OD channels 0.0 0 1,600 1,650 1,700 1,750 1,80 W avelength, nm Wavelength (nm) 3d generation DFA Filter Spectrometer has 20 channels It also has Grating spectrometer with 16 Channels on hydrocarbon peak
Fluorescence & Reflectance
Case Study 1 Fluid Profiling for Connectivity
In-Situ Composition and PVT Laboratory Data
Case Study 1 InSitu Density Final DFA Density Lab. Density
Case Study 2 Complex Reservoir
HC Detection With Fluorescence and Density First hydrocarbons detected 1.5 hours before visible on spectrometer composition and GOR
Formation Tester Downhole Pump Phase Sequence
Dew Point Detection (Retrograde Gas) 2 phase flow 2 phase flow GOR oil gas oil oil gas oil Composition and water fraction Fluor. and Reflect. Flowing pressure Color
Dew Point Detection (Retrograde Gas) single phase flow GOR rate decrease single phase flow Composition and water fraction Fluor. and Reflect. Flowing pressure Color
Dew Point Detection (Retrograde Gas) single phase flow two phase flow GOR Composition and water fraction single phase flow slow rate increase First dew Fluor. and Reflect. Flowing pressure First dew Color
Bubble Point Detection (Volatile Oil) 2 phase flow single phase flow GOR gas oil oil rate decrease Composition and water fraction Fluor. and Reflect. Flowing pressure Color
Conclusions Complex reservoirs require comprehensive analysis of fluid differences. Available technologies and answers provide accurate in-situ fluid analysis. Cases studies indicate excellent in-situ fluid analysis Cases studies indicate excellent in situ fluid analysis accuracy of composition, GOR, CO2, density and fluorescence for reservoir connectivities evaluation, saturation pressure detection and sampling quality assurance.