Petroleum Engineering
Amin Poorzangheneh; Bijan Ghanavati; Borzu Asgari Pirbalouti
Abstract
Oil well cementing is a multi-purpose operation, in which cement slurries are prepared by mixing water, cement and various additives and is pumped into the well in order to isolate productive zones, protect the casing pipe, perform remedial operations, controlling drilling fluid lost or abandon the well. ...
Read More
Oil well cementing is a multi-purpose operation, in which cement slurries are prepared by mixing water, cement and various additives and is pumped into the well in order to isolate productive zones, protect the casing pipe, perform remedial operations, controlling drilling fluid lost or abandon the well. Various additives are used to improve the mechanical properties of the slurry, like cement retarders and accelerators which increase and decrease the thickening time of the cement slurry, respectively. Weight-enhancing additives are materials with specific gravity higher than cement, which can weight-up the slurry to overcome the hydrostatic pressure of mud and performing a good cementing job. Improving the mechanical properties of these type of cement slurries has always been an important issue in the discussion of oil wells cementing. In this study, the effects of nano zeolite on heavy-weight oil well cement slurry were investigated in laboratory to improve the rheological and mechanical properties of the cement. In the designed experiments, nano-zeolite was added to the slurry with the amount of 1, 2 and 3% BWOC (By Weight of Cement). The results showed that nano zeolite acts as an additive to reduce the thickening time, increase the plastic viscosity and reduces the yield point of the slurry. So, it should be noted to adjust the pumping time of the cement slurry by using other additives based on the required cementing job timing schedule. The experiments also showed that in general, the addition of nano-zeolite to the cement slurry from 1 to 3% BWOC led to an increase in the free fluid of the cement slurry, but did not show any effect on the control of the fluid loss. Finally, by adding 2% BWOC of nano zeolite, the compressive strength of the cement stone increased and the initial setting time of cement slurry decreased
Petroleum Engineering – Drilling
Borzu Asgari pirbalouti
Abstract
Among the different operating parameters that must be carefully controlled during the drilling operation, penetration of drilling mud into the permeable zone of formations is one of the essential ones that can have a destructive effect on the productive zone. Thus, the current investigation concentrates ...
Read More
Among the different operating parameters that must be carefully controlled during the drilling operation, penetration of drilling mud into the permeable zone of formations is one of the essential ones that can have a destructive effect on the productive zone. Thus, the current investigation concentrates on investigating the effects of different nanoparticles (NPs), namely SiO2, CuO, and ZnO, considering their size, type, and concentration (0.2 to 2 wt % for each nanoparticle) on the properties of the drilling fluid, including rheology and high- and low-temperature filtration. NPs can improve the rheological properties of the mud by changing the friction coefficient favorably. Moreover, the effects of temperature and pressure as two critical thermodynamic parameters are examined. The results show that it is possible to enhance the rheological properties (viscosity) of the drilling mud to a maximum value of about 20 % if NPs with a concentration of 2 wt % are added to the drilling fluid. Extreme gel strength will lead to high pump initiation pressure to break circulation after the mud is in a static condition for some time. The results reveal that reducing the gelation properties of the drilling mud is possible using low concentrations of NPs. Moreover, the results reveal that SiO2 and ZnO exhibit a lower filtration rate than CuO. Finally, the effects of temperature and pressure were investigated, which revealed that regardless of the reductive effect of NPs (reducing the filtration rate from 17.7 to about 10 cm3), increasing the pressure and temperature lead to an increase in the filtration rate (reducing the filtration rate from 67 to 35 cm3). Further, the rheological properties of the mud remain relatively constant.
Petroleum Engineering
Borzu Asgari pirbalouti
Abstract
This study investigated the application of iron oxide nanoparticles in the presence of an external magnetic field to control the rheology of drilling fluids. Drilling fluid rheology is one of the most critical factors in determining the optimal fluid. Drilling fluid must have good rheological properties ...
Read More
This study investigated the application of iron oxide nanoparticles in the presence of an external magnetic field to control the rheology of drilling fluids. Drilling fluid rheology is one of the most critical factors in determining the optimal fluid. Drilling fluid must have good rheological properties to carry the drilled cuttings. On the other hand, polymers in the water-based drilling fluid control fluid loss. In low-density oil-based fluids, where the water content is low, rheological control is generally difficult since there is a limitation in selecting additives. In this study, the ferromagnetic fluid has been generated by adding nanoparticles of Fe3O4 to silicon oil. By adding ferromagnetic fluid to the oil-based mud under the influence of the external magnetic field, we examined the rheological behavior of the oil-based drilling mud. The external magnetic field can be applied in actual conditions in the middle of a magnetic drilling string. The results showed that the magnetic nanoparticles improved the drilling mud rheological properties. Moreover, the viscosity of the oil-based fluid without nanoparticles was measured 2 cP and increased to 33 cP by adding 4 wt % of iron oxide nanoparticles under an external magnetic field of 0.321 T. The magnetic field was also used for water-based mud (WBM), and the results showed that in water-based fluids containing polyanionic cellulose (PAC) polymer, the magnetic field did not have much effect on the rheological properties of the drilling mud compared to oil-based mud (OBM). Since water is the main component of the water-based fluid, increasing the magnetic field reduces the viscosity of the water-based fluid. The magnetic field increased fluid’s rheology by adding iron oxide nanoparticles to the polymer-based fluid. The viscosity of the water-based fluid containing nanoparticles increased to 850 cP under the magnetic field.
