valiahmad sajjadian - Academia.edu (original) (raw)
Papers by valiahmad sajjadian
Proceedings of Latin American and Caribbean Petroleum Engineering Conference, 1999
In a well fractured reservoir that has a gas cap, after commencement of production the gas cap ex... more In a well fractured reservoir that has a gas cap, after commencement of production the gas cap expands and the gas-oil contact (GOC) in the fracture system descends. The oil contained within the matrix of the gas invaded zone begins to drain down into the fracture system and into the lower matrix blocks, due to the force of gravity. Some of the oil that is drained out of the upper matrix blocks can reinfiltrate into the lower matrix blocks from the top or side surfaces and can flow down through the areas of contact between blocks. In this study, data on a set of experiments that center on reinfiltration process are presented. The experiments cover fully saturated and desaturated blocks in vertical and inclined positions. The results of our experimental works reveal that the reinfiltration process depends mainly on the physical properties of the matrix block, the rate of oil supplied, and the drainage stage of the block. When oil is trickled at the top of a desaturated block, initially due to an extra capillary pressure gradient the infiltration rate can be higher than the maximum drainage rate of the block. After some time the rate of the drainage approaches that of the infiltration and an almost steady state flow is established. At this condition, the lower portion of the block could drain oil, while the upper portion could be under infiltration process. When the oil is directly supplied on the top of the vertical fracture, its crossflow from fracture to the adjacent matrix is demonstrated. In other words, under certain conditions the high conductivity vertical fractures are not necessarily the primary flow path of the supplied oil. The purpose of this study is to provide a basic understanding of reinfiltration process in fractured porous media.
Velocity anisotropy is the variation of wave velocity along different directions in a material. P... more Velocity anisotropy is the variation of wave velocity along different directions in a material. Preferential orientation of clay mineral alignment, layering, microcracks, low aspect ratio pores and fracturing all causes velocity anisotropy observed in many sedimentary rocks. Our purpose is to find the variation of wave velocity in a different direction as a function of confining pressure in dry saturated samples Shales are the richest lithology in a sedimentary basin and exhibit a relatively large degree of anisotropy. Ultrasonic measurements are carried out on Cambay shale samples to study its anisotropy. The elastic stiffness constants and Thomsen’s parameters are calculated and plotted against the Confining pressure on a suite of two core plugs of the Cambay shale. The variation of velocities on different core plugs of the same suite indicates that the Cambay shale is anisotropic. Rocks mechanical properties like Young’s modulus and Poisson’s ratio are also play an important role...
Polymer Science Series A, 2015
One of the main problems of polymer solutions in enhanced oil recovery applications is their prop... more One of the main problems of polymer solutions in enhanced oil recovery applications is their properties losses after long term aging in electrolyte media. This paper reports preparation and rheological properties and thermal stability of novel weak hydrogels based on sulfonated polyacrylamide crosslinked in electrolyte solutions. Experimental results show that by increasing of crosslinker concentration, storage mod ulus dependency on frequency becomes weaker. At lower gelation temperature, gels with higher crosslinker concentrations exhibit lower storage modulus. Sharp decrease of viscosity value in viscosity shear stress curves, approved existence of yield behavior for sulfonated polyacrylamide/chromium triacetate systems. There is a linear dependency of storage modulus, viscosity and yield stress value on polymer and crosslinker concentrations. Sulfonated polyacrylamide weakly crosslinked samples show higher viscosity than sulfonated polyacrylamide solution after thermal aging. Results of this research suggest the potentials of weakly crosslinked systems based on sulfonated polyacrylamide for oil recovery applications.
Brasil Offshore, 2011
... 2000. 5. Halliburton's Best Practices Carbonate Matrix Acidizing Treatments, Oct... more ... 2000. 5. Halliburton's Best Practices Carbonate Matrix Acidizing Treatments, October 1998. 6. Karami, P., Hashemi, A., Pressure Transient Well Testing Encountered Complexities: A Case Study, SPE-120893, (June 2009). 7 ...
Proceedings of Trinidad and Tobago Energy Resources Conference, 2010
International Oil Conference and Exhibition in Mexico, 2006
Abstract A black oil reservoir simulator has been used to determine the reservoir management and ... more Abstract A black oil reservoir simulator has been used to determine the reservoir management and production strategies to optimize the oil recovery from an offshore low porosity, low permeability carbonate reservoir with permeability of 1-3 md and porosity of ...
49th Annual Logging …, 2008
... Badri, M., Charara, M., Boyd, A., Cassell, B., Nurmi, R., Delhomme, JP, Grace, M., Kenyon, B.... more ... Badri, M., Charara, M., Boyd, A., Cassell, B., Nurmi, R., Delhomme, JP, Grace, M., Kenyon, B., Roestenburg, J., 1995, "Classic Interpretation Problems, Evaluating Carbonates": Oilfield Review, Shclumberger. Akbar, M., Chakravorty, S., Russell, D., Al Deeb, M. A., Saleh Efnik, MR ...
International Journal of Mining Science
As many oil fields go into their final stage of production, novel technologies are necessary in o... more As many oil fields go into their final stage of production, novel technologies are necessary in order to maintain the production and increase the recovery of hydrocarbons. Therefore, advanced technology like Nanotechnology should be coming to overcome the problem of low recovery from reservoirs. Nano fluids were injected as a tertiary recovery method following a secondary water flooding. The experiments were performed at ambient conditions. Interfacial tensions and contact angles were measured in order to help explain the underlying mechanisms behind the increased recovery. In this research paper, the effect of silica nano and carbon nano particles on the wettability alteration in one of the Iran Sand Stone reservoir is mentioned. The results obtained from experiments show that these nano particles are suitable enhanced oil recovery (E.O.R) agents in water wet sand stone formations. Silica nano and carbon nano particles demonstrated same results in the wettability alteration of core plug. It was observed that the oil recovery increased by 5% when 0.05 wt. % Sio 2 nano fluid was injected into the core sample in a tertiary mode.
The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock ... more The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock surface improves oil recovery and reduces the unwanted water production. In this study, the adsorption behavior of dilute polymeric systems based on sulfonated polyacrylamide on the glass particles surfaces (representative of sandstone reservoirs) was investigated and the effect of this phenomenon on changing their surface properties was examined. Results show that crosslinked polymeric samples have lower adsorption on glassy surface comparing with uncrosslinked sulfonated polyacrylamide solution. Furthermore, the contact angle tests results showed that crosslinked samples change the surface property of glass particle less than sulfonated polyacrylamide solution. In addition the Langmuir isotherm model fitted the isotherm data better than the Freundlich model for these dilute polymeric systems. Furthermore, study of the thermodynamic of adsorption showed that their adsorption behavior on glassy surfaces is a spontaneous and exothermic process.
Proceedings of Trinidad and Tobago Energy Resources Conference, 2010
Abstract Sirri-A is a large offshore producing field which is located in the Persian Gulf, in Ira... more Abstract Sirri-A is a large offshore producing field which is located in the Persian Gulf, in Iranian sector, with an OOIP of about 2 MMMSTB. Its reservoir with porosity range of 3-21 percent and a permeability range of 0.1-3 md is situated in Ilam formation which is a ...
... The studied field is among the heteroneneous carbonate reservoirs in southwest of Iran. ... R... more ... The studied field is among the heteroneneous carbonate reservoirs in southwest of Iran. ... Recentinvestigation and research has shown that reservoirs are anisotropic and heterogeneous especially ... Shallow resistivity, Ci is conductivity of the buttons, and m is cementation factor. ...
... at initial reservoir conditions. The field has neither active aquifer nor gas cap. The reserv... more ... at initial reservoir conditions. The field has neither active aquifer nor gas cap. The reservoir porosity ranges from 3% to 28% with an average of 15% and the permeability ranges from 1 md to 100 md. The overall production is ...
Proceedings of Latin American and Caribbean Petroleum Engineering Conference, 1999
In a well fractured reservoir that has a gas cap, after commencement of production the gas cap ex... more In a well fractured reservoir that has a gas cap, after commencement of production the gas cap expands and the gas-oil contact (GOC) in the fracture system descends. The oil contained within the matrix of the gas invaded zone begins to drain down into the fracture system and into the lower matrix blocks, due to the force of gravity. Some of the oil that is drained out of the upper matrix blocks can reinfiltrate into the lower matrix blocks from the top or side surfaces and can flow down through the areas of contact between blocks. In this study, data on a set of experiments that center on reinfiltration process are presented. The experiments cover fully saturated and desaturated blocks in vertical and inclined positions. The results of our experimental works reveal that the reinfiltration process depends mainly on the physical properties of the matrix block, the rate of oil supplied, and the drainage stage of the block. When oil is trickled at the top of a desaturated block, initially due to an extra capillary pressure gradient the infiltration rate can be higher than the maximum drainage rate of the block. After some time the rate of the drainage approaches that of the infiltration and an almost steady state flow is established. At this condition, the lower portion of the block could drain oil, while the upper portion could be under infiltration process. When the oil is directly supplied on the top of the vertical fracture, its crossflow from fracture to the adjacent matrix is demonstrated. In other words, under certain conditions the high conductivity vertical fractures are not necessarily the primary flow path of the supplied oil. The purpose of this study is to provide a basic understanding of reinfiltration process in fractured porous media.
Velocity anisotropy is the variation of wave velocity along different directions in a material. P... more Velocity anisotropy is the variation of wave velocity along different directions in a material. Preferential orientation of clay mineral alignment, layering, microcracks, low aspect ratio pores and fracturing all causes velocity anisotropy observed in many sedimentary rocks. Our purpose is to find the variation of wave velocity in a different direction as a function of confining pressure in dry saturated samples Shales are the richest lithology in a sedimentary basin and exhibit a relatively large degree of anisotropy. Ultrasonic measurements are carried out on Cambay shale samples to study its anisotropy. The elastic stiffness constants and Thomsen’s parameters are calculated and plotted against the Confining pressure on a suite of two core plugs of the Cambay shale. The variation of velocities on different core plugs of the same suite indicates that the Cambay shale is anisotropic. Rocks mechanical properties like Young’s modulus and Poisson’s ratio are also play an important role...
Polymer Science Series A, 2015
One of the main problems of polymer solutions in enhanced oil recovery applications is their prop... more One of the main problems of polymer solutions in enhanced oil recovery applications is their properties losses after long term aging in electrolyte media. This paper reports preparation and rheological properties and thermal stability of novel weak hydrogels based on sulfonated polyacrylamide crosslinked in electrolyte solutions. Experimental results show that by increasing of crosslinker concentration, storage mod ulus dependency on frequency becomes weaker. At lower gelation temperature, gels with higher crosslinker concentrations exhibit lower storage modulus. Sharp decrease of viscosity value in viscosity shear stress curves, approved existence of yield behavior for sulfonated polyacrylamide/chromium triacetate systems. There is a linear dependency of storage modulus, viscosity and yield stress value on polymer and crosslinker concentrations. Sulfonated polyacrylamide weakly crosslinked samples show higher viscosity than sulfonated polyacrylamide solution after thermal aging. Results of this research suggest the potentials of weakly crosslinked systems based on sulfonated polyacrylamide for oil recovery applications.
Brasil Offshore, 2011
... 2000. 5. Halliburton's Best Practices Carbonate Matrix Acidizing Treatments, Oct... more ... 2000. 5. Halliburton's Best Practices Carbonate Matrix Acidizing Treatments, October 1998. 6. Karami, P., Hashemi, A., Pressure Transient Well Testing Encountered Complexities: A Case Study, SPE-120893, (June 2009). 7 ...
Proceedings of Trinidad and Tobago Energy Resources Conference, 2010
International Oil Conference and Exhibition in Mexico, 2006
Abstract A black oil reservoir simulator has been used to determine the reservoir management and ... more Abstract A black oil reservoir simulator has been used to determine the reservoir management and production strategies to optimize the oil recovery from an offshore low porosity, low permeability carbonate reservoir with permeability of 1-3 md and porosity of ...
49th Annual Logging …, 2008
... Badri, M., Charara, M., Boyd, A., Cassell, B., Nurmi, R., Delhomme, JP, Grace, M., Kenyon, B.... more ... Badri, M., Charara, M., Boyd, A., Cassell, B., Nurmi, R., Delhomme, JP, Grace, M., Kenyon, B., Roestenburg, J., 1995, "Classic Interpretation Problems, Evaluating Carbonates": Oilfield Review, Shclumberger. Akbar, M., Chakravorty, S., Russell, D., Al Deeb, M. A., Saleh Efnik, MR ...
International Journal of Mining Science
As many oil fields go into their final stage of production, novel technologies are necessary in o... more As many oil fields go into their final stage of production, novel technologies are necessary in order to maintain the production and increase the recovery of hydrocarbons. Therefore, advanced technology like Nanotechnology should be coming to overcome the problem of low recovery from reservoirs. Nano fluids were injected as a tertiary recovery method following a secondary water flooding. The experiments were performed at ambient conditions. Interfacial tensions and contact angles were measured in order to help explain the underlying mechanisms behind the increased recovery. In this research paper, the effect of silica nano and carbon nano particles on the wettability alteration in one of the Iran Sand Stone reservoir is mentioned. The results obtained from experiments show that these nano particles are suitable enhanced oil recovery (E.O.R) agents in water wet sand stone formations. Silica nano and carbon nano particles demonstrated same results in the wettability alteration of core plug. It was observed that the oil recovery increased by 5% when 0.05 wt. % Sio 2 nano fluid was injected into the core sample in a tertiary mode.
The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock ... more The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock surface improves oil recovery and reduces the unwanted water production. In this study, the adsorption behavior of dilute polymeric systems based on sulfonated polyacrylamide on the glass particles surfaces (representative of sandstone reservoirs) was investigated and the effect of this phenomenon on changing their surface properties was examined. Results show that crosslinked polymeric samples have lower adsorption on glassy surface comparing with uncrosslinked sulfonated polyacrylamide solution. Furthermore, the contact angle tests results showed that crosslinked samples change the surface property of glass particle less than sulfonated polyacrylamide solution. In addition the Langmuir isotherm model fitted the isotherm data better than the Freundlich model for these dilute polymeric systems. Furthermore, study of the thermodynamic of adsorption showed that their adsorption behavior on glassy surfaces is a spontaneous and exothermic process.
Proceedings of Trinidad and Tobago Energy Resources Conference, 2010
Abstract Sirri-A is a large offshore producing field which is located in the Persian Gulf, in Ira... more Abstract Sirri-A is a large offshore producing field which is located in the Persian Gulf, in Iranian sector, with an OOIP of about 2 MMMSTB. Its reservoir with porosity range of 3-21 percent and a permeability range of 0.1-3 md is situated in Ilam formation which is a ...
... The studied field is among the heteroneneous carbonate reservoirs in southwest of Iran. ... R... more ... The studied field is among the heteroneneous carbonate reservoirs in southwest of Iran. ... Recentinvestigation and research has shown that reservoirs are anisotropic and heterogeneous especially ... Shallow resistivity, Ci is conductivity of the buttons, and m is cementation factor. ...
... at initial reservoir conditions. The field has neither active aquifer nor gas cap. The reserv... more ... at initial reservoir conditions. The field has neither active aquifer nor gas cap. The reservoir porosity ranges from 3% to 28% with an average of 15% and the permeability ranges from 1 md to 100 md. The overall production is ...