Mahmoud Khalifeh

Experimental study on the synthesis and characterization of aplite rock-based geopolymers

This paper presents a new method for geopolymer synthesis of ground aplite rock. The resulting geopolymers were easy to manufacture and exhibited promising mechanical properties. Compressive strength testing, X-ray diffraction, and scanning electron microscope analyzes were performed. The results indicated that in manufacturing, the aplite-based geopolymers, potassium-containing systems gave noticeable improvements in comparison with sodium-containing systems. Rheological behavior of the geopolymeric slurry showed non-Newtonian behavior. The Bingham and Herschel–Bulkley models were selected to simulate the viscosities of the slurries. The Bingham model fitted to the measured data with an average deviation of 1.65 (lbf/100 ft2) while the Herschel–Bulkley model showed large deviations from the experimental data.

Long-term durability of rock-based geopolymers aged at downhole conditions for oil well cementing operations

The long-term integrity of rock-based geopolymers was studied in corrosive environments. The geopolymers were cured for 7 days at ambient conditions. Afterwards, the geopolymers were exposed to crude oil, brine and H2S in brine at 100 °C and elevated pressures. The compressive strength, tensile strength, weight and volume changes were measured prior and after 3, 6 and 12 months of exposure. The measurements showed a turning point after 6 months of ageing. Whereas the compressive strength and tensile strength started to increase when the specimens were exposed to crude oil and brine, the specimens that were exposed to H2S experienced some degradation. Permeability of geopolymers before exposure and after 12 months of exposure to the crude oil and brine was very low. The permeability of the specimens which were exposed to H2S was not measureable. Substantial volume changes were observed for the geopolymers which were exposed to H2S and brine.

An Experimental Investigation of Permeability Impairment Under Dynamic Flow Conditions Due to Natural Depletion in an Iranian Oilfield

Asphaltene deposition is an issue that has received much attention since it has been shown to be the cause of major production problems. It leads to permeability reduction under the processes of natural depletion as well as hydrocarbon gas/CO2 injection. Though a great deal of researches have focused on studying permeability impairment in reservoir rocks, little is known about the asphaltene deposition mechanisms that control the permeability reduction for Iranian reservoirs. In this work, an experimental effort is made to investigate the permeability impairment of core samples of Iranian oil reservoirs. The experiments are performed on both sandstone and carbonate rock types at reservoir temperature and pressure. The mass balance was used for evaluating of porosity reduction during the experiments. The results indicate that the dominant deposition mechanism changes as production proceeds. In addition, it has been found that the primary mechanism in permeability impairment is surface deposition. On the other hand, entrainment of asphaltene particles is manifested when outlet pressure drops from 4,200 to 3,800 Psig for both sandstone and carbonate samples. It can be drawn that asphaltene entrainment dependence to pressure is much more than that to the injected pore volume. This research illuminates the deposition mechanisms and determines dynamic parameters of asphaltene deposition, which are necessary to devise reliable prevention strategies.

Development and Characterization of Norite-Based Cementitious Binder from an Ilmenite Mine Waste Stream

This is an open access article distributed under the Creative Commons Attribution License, originally published in Advances in Materials Science and Engineering.

The Estimation of Fault Displacement by Analyzing Static Reservoir Pressure Data

Faults are geotechnical attributes that modify the internal architecture of reservoir, either as flow-barrier (sealing) or as a passageway for oil and gas to move in and up. Accurate layer representation, layering, and assessment of fault properties have important roles in characterizing reservoirs, especially in dynamic reservoir modeling. Fault displacements are commonly calculated by seismic data. However small displacements are calculated by logging data. Therefore, introducing an alternating calculation method instead of logging interpretation could be very useful for small fault displacements. In this study, integration of pressure, pressure-volume-temperature (PVT), and logging data were collected from two wells in one of southern Irans carbonate oil reservoirs have been provided important information on the behavior of the fault between them. A typical crude oil fluid sample of the both wells showed clear difference between PVT data and primarily existence of the fault was detected during a 2D customary seismic interpretation. The authors analyze in detail two sets of reservoir pressure data, which are collected from two vertical wells belongs to one reservoir, to present a methodology to interpret faults displacement. In this method by using the generated equations and then comparing them that were concluded from true vertical depth versus pressure of water zones for both wells, fault displacement has been calculated. In the last step, results are confirmed by interpreting the displacement that is taken from the logging data. In some zones, as a result of the operational failures or reservoir fluid viscous effects, measured vertical pressure profile does not correspondent the hydrostatic gradient of the in situ fluid. Hence, an average reservoirs pressure gradient from different zones has been used in the calculations to minimize their effect.