Effective Medium Modeling of CO2-Sequestered Carbonate Reservoir

2019 ◽  
pp. 145-160
Author(s):  
Ranjana Ghosh ◽  
Mrinal K. Sen
Keyword(s):  
Effective Medium ◽  
Carbonate Reservoir

Using rock physics models to validate rock composition from multimineral log analysis

Geophysics ◽  
2021 ◽  
pp. 1-69
Author(s):  
Liwei Cheng ◽  
Manika Prasad ◽  
Reinaldo J. Michelena ◽  
Ali Tura ◽  
Shamima Akther ◽  
...  
Keyword(s):  
Quality Control ◽  
Reservoir Characterization ◽  
Rock Physics ◽  
Inequality Constraint ◽  
Effective Medium ◽  
Carbonate Reservoir ◽  
Log Analysis ◽  
Evaluation Tool ◽  
Rock Composition ◽  
Effective Medium Models

Multimineral log analysis is a quantitative formation evaluation tool for geological and petrophysical reservoir characterization. Rock composition can be estimated by solving equations that relate log measurements to the petrophysical endpoints of minerals and fluids. Due to errors in log data and uncertainties in petrophysical endpoints of constituents, we propose using effective medium models from rock physics as additional independent information to validate or constrain the results. In this paper, we examine the Voigt-Reuss (VR) bound model, self-consistent approximation (SCA), and differential effective medium (DEM). The VR bound model provides the first-order quality control of multimineral results. We first show a conventional carbonate reservoir study with intervals where the predicted effective medium models from multimineral results are inconsistent with the measured elastic properties. We use the VR bound model as an inequality constraint in multimineral analysis for plausible alternative solutions. SCA and DEM models provide good estimates in low porosity intervals and imply geological information for the porous intervals. Then, we show a field case of the Bakken and Three Forks formations. A linear interpolation of the VR bound model helps validate multimineral results and approximate the elastic moduli of clay. There are two major advantages to use our new method (a) rock physics effective medium models provide independent quality control of petrophysical multimineral results, and (b) multimineral information leads to realistic rock physics models.

scholarly journals Optimization of Rock Physics Models by Combining the Differential Effective Medium (DEM) and Adaptive Batzle-Wang Methods in “R” Field, East Java

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
M. Wahdanadi Haidar ◽  
Reza Wardhana ◽  
M. Iskan ◽  
M. Syamsu Rosid
Keyword(s):  
Elastic Modulus ◽  
Wave Velocity ◽  
Carbonate Rocks ◽  
Effective Medium ◽  
Carbonate Reservoir ◽  
P Wave ◽  
S Wave ◽  
P Wave Velocity ◽  
Reservoir Conditions ◽  
Pore Types

The pore systems in carbonate reservoirs are more complex than the pore systems in clastic rocks. There are three types of pores in carbonate rocks: interparticle pores, stiff pores and cracks. The complexity of the pore types can lead to changes in the P-wave velocity by up to 40%, and carbonate reservoir characterization becomes difficult when the S-wave velocity is estimated using the dominant interparticle pore type only. In addition, the geometry of the pores affects the permeability of the reservoir. Therefore, when modelling the elastic modulus of the rock it is important to take into account the complexity of the pore types in carbonate rocks. The Differential Effective Medium (DEM) is a method for modelling the elastic modulus of the rock that takes into account the heterogeneity in the types of pores in carbonate rocks by adding pore-type inclusions little by little into the host material until the required proportion of the material is reached. In addition, the model is optimized by calculating the bulk modulus of the fluid filler porous rock under reservoir conditions using the Adaptive Batzle-Wang method. Once a fluid model has been constructed under reservoir conditions, the model is entered as input for the P-wave velocity model, which is then used to estimate the velocity of the S-wave and the proportion of primary and secondary pore types in the rock. Changes in the characteristics of the P-wave which are sensitive to the presence of fluid lead to improvements in the accuracy of the P-wave model, so the estimated S-wave velocity and the calculated ratio of primary and secondary pores in the reservoir are more reliable.

ANALISA POTENSI MINYAK DAN GAS BUMI DENGAN ATRIBUT SEISMIK PADA BATUAN KARBONAT LAPANGAN *ZEFARA* CEKUNGAN SUMATRA SELATAN

KURVATEK ◽  
2017 ◽  
Vol 1 (2) ◽  
pp. 21-31
Author(s):  
Fatimah Miharno
Keyword(s):  
Instantaneous Frequency ◽  
Carbonate Reservoir ◽  
Control Analysis ◽  
High Porosity ◽  
Hydrocarbon Accumulation ◽  
Seismic Attribute ◽  
Data Set ◽  
Log Data ◽  
Low Amplitude ◽  
Rms Amplitude

ABSTRACT*Zefara* Field formation Baturaja on South Sumatra Basin is a reservoir carbonate and prospective gas. Data used in this research were 3D seismik data, well logs, and geological information. According to geological report known that hidrocarbon traps in research area were limestone lithological layer as stratigraphical trap and faulted anticline as structural trap. The study restricted in effort to make a hydrocarbon accumulation and a potential carbonate reservoir area maps with seismic attribute. All of the data used in this study are 3D seismic data set, well-log data and check-shot data. The result of the analysis are compared to the result derived from log data calculation as a control analysis. Hydrocarbon prospect area generated from seismic attribute and are divided into three compartments. The seismic attribute analysis using RMS amplitude method and instantaneous frequency is very effective to determine hydrocarbon accumulation in *Zefara* field, because low amplitude from Baturaja reservoir. Low amplitude hints low AI, determined high porosity and high hydrocarbon contact (HC).  Keyword: Baturaja Formation, RMS amplitude seismic attribute, instantaneous frequency seismic attribute

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