Haider Dahm | Missan - Academia.edu (original) (raw)
Papers by Haider Dahm
Arabian Journal for Science and Engineering
Iraqi National Journal of Earth Sciences
Abu Dhabi International Petroleum Exhibition & Conference
Drilling operations in deep shales are more challenging due to geomechanical problems such as wel... more Drilling operations in deep shales are more challenging due to geomechanical problems such as wellbore instability. Neglecting the impact of geomechanical issues may lead to drilling drawbacks such as loss of circulation, wellbore collapse, tight hole while tripping, stuck logging tools, and subsequent fishing, stuck pipe, and sidetracking. The directional dependency (anisotropy) of the rock properties, especially the rock strength, cause variation in the wave velocities. Identifying orientation and degree of the anisotropy and its relationship with geomechanical problems is essential for further field development. In this paper, acoustic data from vertical and deviated wells in Zubair Formation, Southern Iraq were performed to provide insights on the state of stress distribution around the wellbore through the Zubair Formation. In addition, interpreting the flexural dispersion curves as the final result of cross-dipole data processing, the maximum stress direction has been obtained...
Journal of Geophysical Research: Solid Earth
The 410 and 660 km discontinuities (d410 and d660, respectively) beneath Alaska and adjacent area... more The 410 and 660 km discontinuities (d410 and d660, respectively) beneath Alaska and adjacent areas are imaged by stacking 75,296 radial receiver functions recorded by 438 broadband seismic stations with up to 30 years of recording period. When the 1-D IASP91 Earth model is used for moveout correction and time depth conversion, significant and spatially systematic variations in the apparent depths of the d410 and d660 are observed. The mean apparent depth of the d410 and d660 for the entire study area is 417 ± 12 km and 665 ± 12 km, respectively, and the mean mantle transition zone (MTZ) thickness is 248 ± 8 km which is statistically identical to the global average. For most of the areas, the undulations of the apparent depths of the d410 and d660 are highly correlated, indicating that lateral velocity variations in the upper mantle above the d410 contribute to the bulk of the observed apparent depth variations by affecting the traveltimes of the P-to-S converted phases from both discontinuities. Beneath central Alaska, a broad zone with greater than normal MTZ thicknesses and shallower than normal d410 is imaged, implying that the subducting Pacific slab has reached the MTZ and is fragmented or significantly thickened. Within the proposed Northern Cordilleran slab window, an overall thinner than normal MTZ is observed and is most likely the result of a depressed d410. This observation, when combined with results from seismic tomography investigations, may indicate advective thermal upwelling from the upper MTZ through the slab window.
Journal of Petroleum Science and Engineering
Abstract The Zubair Reservoir is a regionally extensive oil-producing sandstone sequence which is... more Abstract The Zubair Reservoir is a regionally extensive oil-producing sandstone sequence which is part of the petroleum system in Iraq, Kuwait, Syria, Iran, and Saudi Arabia. Rock mechanical properties are extremely useful in optimizing drilling, production, and reservoir compaction. Hence, an accurate technique for estimating rock mechanical properties may significantly improve the economic revenues derivable from the reservoir. However, information about rock mechanical properties along the depth is often discontinuous and limited to core samples taken within the reservoir interval. The present study aims to predict a continuous profile of rock mechanical properties throughout the depth of the Zubair Reservoir directly from wireline porosity logs. Special characteristics of Zubair sandstone were evaluated and described using thin-section photographs, X-ray diffraction analysis, and scanning electron microscope imaging to identify and characterize the mineralogy, texture, and structure of the sandstone unit. Thereafter, both triaxial and triaxial multistage testing techniques were carried out on 130 plug samples from the Zubair sandstone formation to measure the rock's mechanical properties. Valid local empirical correlations were established between the porosity and these mechanical parameters. The obtained results revealed that the rock mechanical properties are primarily functions of porosity and the direct linear expression is more reliable than power functions and exponential functions. The best relationship obtained between UCS, internal friction angle, Young's modulus, bulk modulus, shear modulus, and Poisson's ratio with porosity had a correlation coefficient (R2) of 0.84, 0.75, 0.80, 0.59, 0.83 and 0.70, respectively. The accuracy of the newly suggested empirical correlations was subjected to statistical analysis. Moreover, these relationships were compared with the existing commonly used correlations reported in the literature on real field data from Zubair sandstone. The results showed that the suggested empirical correlations have a high accuracy and reliability, while the previous correlations could not adequately cover the Zubair sandstone data. This emphasizes the importance of using local correlations to estimate rock mechanical properties. The predicted continuous rock mechanical profile provides a good indication of the strength and stability of the formation around the wellbore. Consequently, it can be used in solving wellbore instability problems; preventing sand production; optimizing drilling processes, which includes the selection of the bit type and drilling parameters; and fracturing operations across the Zubair sandstone reservoir.
SEG Technical Program Expanded Abstracts 2017
Geophysical Research Letters, 2017
Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S... more Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S. using seismic data recorded between 1988 and 2016 by 785 stations. The resulting fast polarization orientations of the 5613 measurements are generally subparallel to the absolute plate motion (APM) and are inconsistent with the strike of major tectonic features. This inconsistency, together with the results of depth estimation using the spatial coherency of the splitting parameters, suggests a mostly asthenospheric origin of the observed azimuthal anisotropy. The observations can be explained by a combined effect of APM-induced mantle fabric and a flow system deflected horizontally around the edges of the keel of the North American continent. Beneath the southern and northeastern portions of the study area, the E-W keel-deflected flow enhances APM-induced fabric and produces mostly E-W fast orientations with large splitting times, while beneath the southeastern U.S., anisotropy from the N-S oriented flow is weakened by the APM.
Geochemistry, Geophysics, Geosystems, 2015
Upper mantle discontinuities are influenced by convection-related thermal heterogeneities arising... more Upper mantle discontinuities are influenced by convection-related thermal heterogeneities arising in complex geodynamic settings. Slab rollback of the Pacific plate and mantle upwelling in the Meso-Cenozoic caused the extension and spreading of continental segments in the South China Block leading to profound variations of the local temperature conditions. We processed 201 teleseismic events beneath 87 stations in the Hainan, Guangdong, and Fujian provinces in the South China Block, and extracted 4172 high-quality receiver functions. We imaged the topography of the local mantle discontinuities by using phase-weighted common conversion point stacking of the receiver functions, which effectively improves the P-to-S-converted phases. We found that the average depths of the discontinuities at 410 and 660 km depth are 414 and 657 km, respectively, while no clearly defined discontinuity at 520 km depth was detected. We mapped the thickness of the mantle transition zone (MTZ), which can reflect temperature and/or compositional heterogeneities as well as the presence of water, and discussed possible geodynamic implications. In particular, we found that the MTZ beneath the Leizhou Peninsula in the Hainan province is 42 km thinner than average. This scenario suggests that the Hainan plume is responsible for positive temperature anomalies between 270 and 380 K and between 200 and 240 K at the 660 and 410 km discontinuities, respectively. We also observed a prominent uplifting of the 660 km boundary beneath the coast regions that may be indicative of lateral flow of the Hainan plume.
Seismological Research Letters, 2016
Ninety eight oriented hand samples were collected from five sites represent calcareous outcrop of... more Ninety eight oriented hand samples were collected from five sites represent calcareous outcrop of Euphrates Formation. These sites were chosen as a completed recovery for a region located at Kufa Quarry-Bahar Al-Najaf area / Middle of Iraq, in order to perform a geophysical study aimed to measure some of the geotechnical and physical properties for these rocks using New Sonicviewer instrument. Moreover, isotropy and seismic impedance were also determined. Longitudinal and Transverse seismic wave velocities had been measured for all samples. The average value for longitudinal velocities is 4294 m/sec and for the transverse velocities is 1870 m/sec. High consolidated limestone, dolomitized limestone and dolomite rock samples show highest longitudinal and transverse seismic velocity values, however, marl rock samples reflect the lowest values. Seismic velocities were measured in three directions;( bed strike, true dip and vertical on bedding plane). Therefore, isotropic factors were determined. It shows the existing of anisotropy between the different types of the considerable rocks of the area.. Finally, Vp, Vs, geotechnical and physical properties were measured for 17 saturated rock samples belong to site four. The results were compared with that of dry samples tests; however, saturated samples give clear decline in their values related to velocity and most of the remaining properties.
Arabian Journal for Science and Engineering
Iraqi National Journal of Earth Sciences
Abu Dhabi International Petroleum Exhibition & Conference
Drilling operations in deep shales are more challenging due to geomechanical problems such as wel... more Drilling operations in deep shales are more challenging due to geomechanical problems such as wellbore instability. Neglecting the impact of geomechanical issues may lead to drilling drawbacks such as loss of circulation, wellbore collapse, tight hole while tripping, stuck logging tools, and subsequent fishing, stuck pipe, and sidetracking. The directional dependency (anisotropy) of the rock properties, especially the rock strength, cause variation in the wave velocities. Identifying orientation and degree of the anisotropy and its relationship with geomechanical problems is essential for further field development. In this paper, acoustic data from vertical and deviated wells in Zubair Formation, Southern Iraq were performed to provide insights on the state of stress distribution around the wellbore through the Zubair Formation. In addition, interpreting the flexural dispersion curves as the final result of cross-dipole data processing, the maximum stress direction has been obtained...
Journal of Geophysical Research: Solid Earth
The 410 and 660 km discontinuities (d410 and d660, respectively) beneath Alaska and adjacent area... more The 410 and 660 km discontinuities (d410 and d660, respectively) beneath Alaska and adjacent areas are imaged by stacking 75,296 radial receiver functions recorded by 438 broadband seismic stations with up to 30 years of recording period. When the 1-D IASP91 Earth model is used for moveout correction and time depth conversion, significant and spatially systematic variations in the apparent depths of the d410 and d660 are observed. The mean apparent depth of the d410 and d660 for the entire study area is 417 ± 12 km and 665 ± 12 km, respectively, and the mean mantle transition zone (MTZ) thickness is 248 ± 8 km which is statistically identical to the global average. For most of the areas, the undulations of the apparent depths of the d410 and d660 are highly correlated, indicating that lateral velocity variations in the upper mantle above the d410 contribute to the bulk of the observed apparent depth variations by affecting the traveltimes of the P-to-S converted phases from both discontinuities. Beneath central Alaska, a broad zone with greater than normal MTZ thicknesses and shallower than normal d410 is imaged, implying that the subducting Pacific slab has reached the MTZ and is fragmented or significantly thickened. Within the proposed Northern Cordilleran slab window, an overall thinner than normal MTZ is observed and is most likely the result of a depressed d410. This observation, when combined with results from seismic tomography investigations, may indicate advective thermal upwelling from the upper MTZ through the slab window.
Journal of Petroleum Science and Engineering
Abstract The Zubair Reservoir is a regionally extensive oil-producing sandstone sequence which is... more Abstract The Zubair Reservoir is a regionally extensive oil-producing sandstone sequence which is part of the petroleum system in Iraq, Kuwait, Syria, Iran, and Saudi Arabia. Rock mechanical properties are extremely useful in optimizing drilling, production, and reservoir compaction. Hence, an accurate technique for estimating rock mechanical properties may significantly improve the economic revenues derivable from the reservoir. However, information about rock mechanical properties along the depth is often discontinuous and limited to core samples taken within the reservoir interval. The present study aims to predict a continuous profile of rock mechanical properties throughout the depth of the Zubair Reservoir directly from wireline porosity logs. Special characteristics of Zubair sandstone were evaluated and described using thin-section photographs, X-ray diffraction analysis, and scanning electron microscope imaging to identify and characterize the mineralogy, texture, and structure of the sandstone unit. Thereafter, both triaxial and triaxial multistage testing techniques were carried out on 130 plug samples from the Zubair sandstone formation to measure the rock's mechanical properties. Valid local empirical correlations were established between the porosity and these mechanical parameters. The obtained results revealed that the rock mechanical properties are primarily functions of porosity and the direct linear expression is more reliable than power functions and exponential functions. The best relationship obtained between UCS, internal friction angle, Young's modulus, bulk modulus, shear modulus, and Poisson's ratio with porosity had a correlation coefficient (R2) of 0.84, 0.75, 0.80, 0.59, 0.83 and 0.70, respectively. The accuracy of the newly suggested empirical correlations was subjected to statistical analysis. Moreover, these relationships were compared with the existing commonly used correlations reported in the literature on real field data from Zubair sandstone. The results showed that the suggested empirical correlations have a high accuracy and reliability, while the previous correlations could not adequately cover the Zubair sandstone data. This emphasizes the importance of using local correlations to estimate rock mechanical properties. The predicted continuous rock mechanical profile provides a good indication of the strength and stability of the formation around the wellbore. Consequently, it can be used in solving wellbore instability problems; preventing sand production; optimizing drilling processes, which includes the selection of the bit type and drilling parameters; and fracturing operations across the Zubair sandstone reservoir.
SEG Technical Program Expanded Abstracts 2017
Geophysical Research Letters, 2017
Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S... more Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S. using seismic data recorded between 1988 and 2016 by 785 stations. The resulting fast polarization orientations of the 5613 measurements are generally subparallel to the absolute plate motion (APM) and are inconsistent with the strike of major tectonic features. This inconsistency, together with the results of depth estimation using the spatial coherency of the splitting parameters, suggests a mostly asthenospheric origin of the observed azimuthal anisotropy. The observations can be explained by a combined effect of APM-induced mantle fabric and a flow system deflected horizontally around the edges of the keel of the North American continent. Beneath the southern and northeastern portions of the study area, the E-W keel-deflected flow enhances APM-induced fabric and produces mostly E-W fast orientations with large splitting times, while beneath the southeastern U.S., anisotropy from the N-S oriented flow is weakened by the APM.
Geochemistry, Geophysics, Geosystems, 2015
Upper mantle discontinuities are influenced by convection-related thermal heterogeneities arising... more Upper mantle discontinuities are influenced by convection-related thermal heterogeneities arising in complex geodynamic settings. Slab rollback of the Pacific plate and mantle upwelling in the Meso-Cenozoic caused the extension and spreading of continental segments in the South China Block leading to profound variations of the local temperature conditions. We processed 201 teleseismic events beneath 87 stations in the Hainan, Guangdong, and Fujian provinces in the South China Block, and extracted 4172 high-quality receiver functions. We imaged the topography of the local mantle discontinuities by using phase-weighted common conversion point stacking of the receiver functions, which effectively improves the P-to-S-converted phases. We found that the average depths of the discontinuities at 410 and 660 km depth are 414 and 657 km, respectively, while no clearly defined discontinuity at 520 km depth was detected. We mapped the thickness of the mantle transition zone (MTZ), which can reflect temperature and/or compositional heterogeneities as well as the presence of water, and discussed possible geodynamic implications. In particular, we found that the MTZ beneath the Leizhou Peninsula in the Hainan province is 42 km thinner than average. This scenario suggests that the Hainan plume is responsible for positive temperature anomalies between 270 and 380 K and between 200 and 240 K at the 660 and 410 km discontinuities, respectively. We also observed a prominent uplifting of the 660 km boundary beneath the coast regions that may be indicative of lateral flow of the Hainan plume.
Seismological Research Letters, 2016
Ninety eight oriented hand samples were collected from five sites represent calcareous outcrop of... more Ninety eight oriented hand samples were collected from five sites represent calcareous outcrop of Euphrates Formation. These sites were chosen as a completed recovery for a region located at Kufa Quarry-Bahar Al-Najaf area / Middle of Iraq, in order to perform a geophysical study aimed to measure some of the geotechnical and physical properties for these rocks using New Sonicviewer instrument. Moreover, isotropy and seismic impedance were also determined. Longitudinal and Transverse seismic wave velocities had been measured for all samples. The average value for longitudinal velocities is 4294 m/sec and for the transverse velocities is 1870 m/sec. High consolidated limestone, dolomitized limestone and dolomite rock samples show highest longitudinal and transverse seismic velocity values, however, marl rock samples reflect the lowest values. Seismic velocities were measured in three directions;( bed strike, true dip and vertical on bedding plane). Therefore, isotropic factors were determined. It shows the existing of anisotropy between the different types of the considerable rocks of the area.. Finally, Vp, Vs, geotechnical and physical properties were measured for 17 saturated rock samples belong to site four. The results were compared with that of dry samples tests; however, saturated samples give clear decline in their values related to velocity and most of the remaining properties.