SPE/DGS Saudi Arabia Section Technical Symposium and Exhibition, 2011
Carbonate reservoirs hold more than 60% of the world's total remaining oil and 40% of gas res... more Carbonate reservoirs hold more than 60% of the world's total remaining oil and 40% of gas reserves (Schlumberger, 2007). With recovery factor averaging around 25–30%, these reservoirs still have substantial amount of trapped hydrocarbons. The primary reason for this poor exploitation of reserves in carbonate stems from the fact that it is challenging to characterize storage and flow properties in these reservoir. Carbonate rocks are known to exhibit depositional and developmental processes (EOR flooding) related heterogeneity. Diagenetic processes like dissolution and precipitation in presence of certain fluid types such as: brine, may have drastic effects on the matrix properties (Eberli, 2003). Diagenesis can trigger heterogeneous distribution of petrophysical properties that may lead to heterogeneous saturation and elastic property distribution. We present our analysis on sensitivity of heterogeneity in carbonate fabric to time-lapse flow and elastic properties variation. We ...
Acoustic properties of rocks and sediments are commonly measured under hydrostatic pressure in th... more Acoustic properties of rocks and sediments are commonly measured under hydrostatic pressure in the laboratory. However, the stress fields in the lithosphere are generally anisotropic. The mechanical properties of sands are sensitive to the stress field and can, for example, drastically affect the borehole stability. Studies that integrate lab and field data require knowledge about extrapolation of acoustic and mechanical
ABSTRACTCarbonate rocks are heterogeneous at various levels from deposition to diagenesis. Any ex... more ABSTRACTCarbonate rocks are heterogeneous at various levels from deposition to diagenesis. Any existing depositional heterogeneity becomes more complex when carbonate rocks are in contact with polar fluids. Our experiments on carbonate rocks show that change in textural heterogeneity leads to heterogeneity in the distribution of storage and flow properties that may govern changes in saturation patterns. This would be akin to any carbonate reservoir with a mix of heterogeneous and homogeneous facies within a formation and their control on saturation distribution in response to a standard imbibition process. Associated with the saturation pattern heterogeneities, the resultant elastic property distributions also change. We quantify this heterogeneity and its effects on flow and seismic properties based on a few textural extremes of fabric heterogeneity in samples that can exist in any typical carbonate reservoir system. Our measurements show that textural heterogeneity can lead to ani...
ABSTRACTCharacterizing the pore space of rock samples using three‐dimensional (3D) X‐ray computed... more ABSTRACTCharacterizing the pore space of rock samples using three‐dimensional (3D) X‐ray computed tomography images is a crucial step in digital rock physics. Indeed, the quality of the pore network extracted has a high impact on the prediction of rock properties such as porosity, permeability and elastic moduli. In carbonate rocks, it is usually very difficult to find a single image resolution which fully captures the sample pore network because of the heterogeneities existing at different scales. Hence, to overcome this limitation a multiscale analysis of the pore space may be needed. In this paper, we present a method to estimate porosity and elastic properties of clean carbonate (without clay content) samples from 3D X‐ray microtomography images at multiple resolutions. We perform a three‐phase segmentation to separate grains, pores and unresolved porous phase using 19 μm resolution images of each core plug. Then, we use images with higher resolution (between 0.3 and 2 μm) of mi...
SPE/DGS Saudi Arabia Section Technical Symposium and Exhibition, 2011
Carbonate reservoirs hold more than 60% of the world's total remaining oil and 40% of gas res... more Carbonate reservoirs hold more than 60% of the world's total remaining oil and 40% of gas reserves (Schlumberger, 2007). With recovery factor averaging around 25–30%, these reservoirs still have substantial amount of trapped hydrocarbons. The primary reason for this poor exploitation of reserves in carbonate stems from the fact that it is challenging to characterize storage and flow properties in these reservoir. Carbonate rocks are known to exhibit depositional and developmental processes (EOR flooding) related heterogeneity. Diagenetic processes like dissolution and precipitation in presence of certain fluid types such as: brine, may have drastic effects on the matrix properties (Eberli, 2003). Diagenesis can trigger heterogeneous distribution of petrophysical properties that may lead to heterogeneous saturation and elastic property distribution. We present our analysis on sensitivity of heterogeneity in carbonate fabric to time-lapse flow and elastic properties variation. We ...
Acoustic properties of rocks and sediments are commonly measured under hydrostatic pressure in th... more Acoustic properties of rocks and sediments are commonly measured under hydrostatic pressure in the laboratory. However, the stress fields in the lithosphere are generally anisotropic. The mechanical properties of sands are sensitive to the stress field and can, for example, drastically affect the borehole stability. Studies that integrate lab and field data require knowledge about extrapolation of acoustic and mechanical
ABSTRACTCarbonate rocks are heterogeneous at various levels from deposition to diagenesis. Any ex... more ABSTRACTCarbonate rocks are heterogeneous at various levels from deposition to diagenesis. Any existing depositional heterogeneity becomes more complex when carbonate rocks are in contact with polar fluids. Our experiments on carbonate rocks show that change in textural heterogeneity leads to heterogeneity in the distribution of storage and flow properties that may govern changes in saturation patterns. This would be akin to any carbonate reservoir with a mix of heterogeneous and homogeneous facies within a formation and their control on saturation distribution in response to a standard imbibition process. Associated with the saturation pattern heterogeneities, the resultant elastic property distributions also change. We quantify this heterogeneity and its effects on flow and seismic properties based on a few textural extremes of fabric heterogeneity in samples that can exist in any typical carbonate reservoir system. Our measurements show that textural heterogeneity can lead to ani...
ABSTRACTCharacterizing the pore space of rock samples using three‐dimensional (3D) X‐ray computed... more ABSTRACTCharacterizing the pore space of rock samples using three‐dimensional (3D) X‐ray computed tomography images is a crucial step in digital rock physics. Indeed, the quality of the pore network extracted has a high impact on the prediction of rock properties such as porosity, permeability and elastic moduli. In carbonate rocks, it is usually very difficult to find a single image resolution which fully captures the sample pore network because of the heterogeneities existing at different scales. Hence, to overcome this limitation a multiscale analysis of the pore space may be needed. In this paper, we present a method to estimate porosity and elastic properties of clean carbonate (without clay content) samples from 3D X‐ray microtomography images at multiple resolutions. We perform a three‐phase segmentation to separate grains, pores and unresolved porous phase using 19 μm resolution images of each core plug. Then, we use images with higher resolution (between 0.3 and 2 μm) of mi...
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