Effect of reservoir properties changes on time-lapse synthetics for well 31 in Gachsaran Field, Iran

2005 ◽  
Vol 24 (8) ◽  
pp. 841-844
Author(s):  
Abdolrasoul Khoshood ◽  
M. K. Ghassem Alaskari ◽  
S. J. Hashemi
Keyword(s):  
Time Lapse ◽  
Reservoir Properties

Optimal dynamic rock-fluid physics template validated by petroelastic reservoir modeling

Geophysics ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. O45-O58 ◽  
Author(s):  
Alireza Shahin ◽  
Robert Tatham ◽  
Paul Stoffa ◽  
Kyle Spikes
Keyword(s):  
Sensitivity Analysis ◽  
Acoustic Impedance ◽  
Velocity Ratio ◽  
Rapid Change ◽  
Time Lapse ◽  
Seismic Attributes ◽  
Reservoir Modeling ◽  
Reservoir Model ◽  
Reservoir Properties ◽  
Fluid Saturation

Separation of fluid pore pressure and saturation using inverted time-lapse seismic attributes is a mandatory task for field development. Multiple pairs of inversion-derived attributes can be used in a crossplot domain. We performed a sensitivity analysis to determine an optimal crossplot, and the validity of the separation is tested with a comprehensive petroelastic reservoir model. We simulated a poorly consolidated shaly sandstone reservoir based on a prograding near-shore depositional environment. A model of effective porosity is first simulated by Gaussian geostatistics. Well-known theoretical and experimental petrophysical correlations were then efficiently combined to consistently simulate reservoir properties. Next, the reservoir model was subjected to numerical simulation of multiphase fluid flow to predict the spatial distributions of fluid saturation and pressure. A geologically consistent rock physics model was then used to simulate the inverted seismic attributes. Finally, we conducted a sensitivity analysis of seismic attributes and their crossplots as a tool to discriminate the effect of pressure and saturation. The sensitivity analysis demonstrates that crossplotting of acoustic impedance versus shear impedance should be the most stable way to separate saturation and pressure changes compared to other crossplots (e.g., velocity ratio versus acoustic impedance). We also demonstrated that the saturation and pressure patterns were detected in most of the time-lapse scenarios; however, the saturation pattern is more likely detectable because the percentage in pressure change is often lower than that of the saturation change. Imperfections in saturation and pressure patterns exist in various forms, and they can be explained by the interaction of saturation and pressure, the diffusive nature of pressure, and rapid change in pressure due to production operations.

Time-lapse monitoring of CO2 sequestration: A site investigation through integration of reservoir properties, seismic imaging, and borehole and surface gravity data

Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. WA15-WA24 ◽  
Author(s):  
Richard A. Krahenbuhl ◽  
Cericia Martinez ◽  
Yaoguo Li ◽  
Guy Flanagan
Keyword(s):  
Gravity Data ◽  
Site Investigation ◽  
Time Lapse ◽  
Density Change ◽  
Joint Surface ◽  
Gravity Inversion ◽  
Borehole Data ◽  
Reservoir Properties ◽  
Entire Study ◽  
Surface Time

We have developed a feasibility study on the application of time-lapse gravity as a monitoring tool for a proposed [Formula: see text] sequestration test site. The results are a component of a larger geotechnical suitability study to evaluate a specific field’s potential for [Formula: see text] storage and to evaluate viable techniques for effective monitoring there. The reservoir model for this study was constructed from detailed reservoir data available through separate reservoir characterization studies of the field. The gravity inversion used was a highly constrained binary approach that incorporated reservoir geometry from seismic data and the internal 3D distributions of density change predicted from the reservoir engineering database. Incorporating borehole data for joint surface/borehole monitoring further improved the potential of time-lapse gravity to define [Formula: see text] movement during sequestration. In this paper, we present a subset of the entire study. Our results indicate that the site likely has a favorable combination of geometry, depth, thickness, and predicted density change from [Formula: see text] movement to be effectively monitored with surface time-lapse gravity.

Time-lapse seismic modeling for CO2 sequestration at the Dickman Oilfield, Kansas

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. B81-B95 ◽  
Author(s):  
Jintan Li ◽  
Christopher Liner ◽  
Robert Stewart
Keyword(s):  
Oil Recovery ◽  
Carbon Capture And Storage ◽  
Flow Simulation ◽  
Time Lapse ◽  
Primary Objective ◽  
Added Value ◽  
Time Shift ◽  
Oil Reservoir ◽  
Reservoir Properties ◽  
Leakage Test

Carbon dioxide capture and injection into the subsurface has aroused great interest in the past few years as a method to enhance oil recovery and mitigate [Formula: see text] emissions. The Dickman Oilfield located in Kansas provides two possible [Formula: see text] sequestration targets: a regional deep saline reservoir (the primary objective) and a shallower mature depleted oil reservoir (secondary). We focused on the shallower depleted oil reservoir through a 250-year flow-simulation scenario and a fault leakage test. Seismic responses at various time intervals were simulated to help monitor [Formula: see text] flow paths and injection stability. A complex and realistic geologic model with unconformity was embedded in the flow-simulation model. A regridding technique was used that assigned geologic values to a regular seismic grid that allowed 2D acoustic and elastic finite-difference simulation. Gassmann fluid substitution theory was used to obtain the reservoir properties with different [Formula: see text] saturations, and the vertical seismic profile was used to assist in identifying geologic layers. A [Formula: see text] plume and flow path from the leakage test can be detected from the differences in seismic data (5 to 10 ms time shift) from the first year of injection and the last year of monitoring. This was supported by comparison with the prestack field data available in the Dickman Oilfield. [Formula: see text]-induced reflectivity changes are relatively larger for PS events than for PP events, implying that multicomponent data acquisition and processing may give added value to characterization and monitoring of carbon capture and storage projects. We assessed 4D seismic monitoring in the evaluation of long-term [Formula: see text] containment stability for the Dickman Oilfield and suggested that time-lapse surveys will be useful.

scholarly journals Streamline-Based Time-Lapse-Seismic-Data Integration Incorporating Pressure and Saturation Effects

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1261-1279 ◽  
Author(s):  
Shingo Watanabe ◽  
Jichao Han ◽  
Gill Hetz ◽  
Akhil Datta-Gupta ◽  
Michael J. King ◽  
...  
Keyword(s):  
High Resolution ◽  
Finite Difference ◽  
Seismic Data ◽  
History Matching ◽  
Flow Simulation ◽  
Time Lapse ◽  
Production Data ◽  
Reservoir Properties ◽  
Fluid Saturation ◽  
Saturation Effects

Summary We present an efficient history-matching technique that simultaneously integrates 4D repeat seismic surveys with well-production data. This approach is particularly well-suited for the calibration of the reservoir properties of high-resolution geologic models because the seismic data are areally dense but sparse in time, whereas the production data are finely sampled in time but spatially averaged. The joint history matching is performed by use of streamline-based sensitivities derived from either finite-difference or streamline-based flow simulation. For the most part, earlier approaches have focused on the role of saturation changes, but the effects of pressure have largely been ignored. Here, we present a streamline-based semianalytic approach for computing model-parameter sensitivities, accounting for both pressure and saturation effects. The novelty of the method lies in the semianalytic sensitivity computations, making it computationally efficient for high-resolution geologic models. The approach is implemented by use of a finite-difference simulator incorporating the detailed physics. Its efficacy is demonstrated by use of both synthetic and field applications. For both the synthetic and the field cases, the advantages of incorporating the time-lapse variations are clear, seen through the improved estimation of the permeability distribution, the pressure profile, the evolution of the fluid saturation, and the swept volumes.

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