ORCID Profile
0000-0003-3252-4450
Current Organisations
Southern University at Shreveport
,
University of Adelaide
,
University of Alaska Fairbanks
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Publisher: SPE
Date: 31-03-2007
DOI: 10.2118/107024-MS
Abstract: Land subsidances around the world and also several casing collapses in some fields of Iran, in drilling and producing time, and also in the period of no production, emphasis the rule of geomechanic factors, the overview of Geomechanical studies of fractured reservoirs. It's clear to predict subsidence (rock compressibility) in sandstone rocks, and some of the professional experts have been worked on it, but about the fractured reservoirs, there are some differences. Regarding to the depth and size of fractured reservoir, in most cases there is no evidences in the surface related to compressibility of underground producing formation, that's why many of petroleum engineers neglect it, so they don't study it in the modeling and reservoir management while some of downhole assemblies problems are related to the pore pressure decrease, porosity loss and in some cases fault activation were caused by subsidence. And we will show in this paper that Subsidence occurs in the Fractured reservoirs and beside the damages, petroleum experts can use it to increase recovery rate of oil and gas.
Publisher: Walter de Gruyter GmbH
Date: 05-2018
Abstract: The oil and gas industries remain an important drive for the world economy. On one hand, global demand for fossil fuels is still rising, and on the other hand, companies face complex investment challenges due to the harsh operational environment of exploration and production activities. Workforce regulations aim to provide a safe and secured working environment. However, exploration and production activities still cause local and global environmental risks such as groundwater contamination, or climate change in broader scale. Analyzing and reporting mechanisms are key performance indicators of sustainable development at the level of oil and gas companies. Obtaining and analyzing required data, nevertheless, seem to be a persistent challenge as to what degree these findings can affect the routine and strategic decisions of the oil and gas companies. In order to enable oil and gas companies to measure and control risks and manage incidents, artificial intelligent technologies in extended monitoring and supervising E& P operations is known to be an efficient prevention strategy. Such tools not only aid in profitability of the oil and gas companies, but also increase awareness of environment and climate change to act more responsibly. In this study, the significances of environmental policies were investigated through interviews with executives and stakeholders, revealing that the implementation of environmental protection policies is affected by the financial stability of the companies, and under severe economic situations, companies seem less enthusiastic in strictly implementing those policies. This paper provides a comprehensive review of emerging technologies in addressing existing and foreseen challenges in sustainable development in oil and gas industries, with the aim of suggesting prime solutions for strategic planning attempts.
Publisher: SPE
Date: 23-04-2017
DOI: 10.2118/185739-MS
Abstract: As exploratory work in Alaska moves beyond the known petroleum basins, new remote areas will be explored, where little sub surface data is available. This paper examines the overburden of Alaska, and develops a general relationship for determining overburden pressures based on the general geographic location in this region. To develop such relationships, well logs available to the Public are used. To characterize the overburden on a large scale, three major sedimentary basins of the Alaska, the North Slope, Nenana Basin, and Cook Inlet Basin, are studied. Overburden is estimated by integrating density of the deposits, from using density log data, and using MATLAB to filter false readings. From this data, a regionalized relationship is developed for pressure vs depth, based on geographical location. The collision of the Pacific Plate and North American Plate has resulted in thrust tectonics, associated with shortening and thickening of the crust at southern part of the Alaska Microplate. The studied basins are located along different locations in this deformation zone and evident with different lithological patterns across a north-south direction. Depending on tectonics and diagenesis of sediments, rocks undergo different compaction processes which make overburden various across this region. As a result of plate tectonics and variation in depositional environments, an increasing trend is observed across the entire Alaska region. Such trend can be used in further exploration work in this region to approximate overburden stress at any location in the state.
Publisher: SPE
Date: 28-03-2012
DOI: 10.2118/150836-MS
Abstract: Knowledge of pore fluid pressure is essential for safe drilling and efficient reservoir modelling. An accurate estimation of pore pressure allows for more efficient selection of casing points and a reliable mud weight design. Current commonly used methods of pore pressure prediction are based on the difference between a ‘normal trend’ in sonic wave velocity, formation resistivity factor (FRF), or d-exponent (a function of drilling parameters) and the observed value of these parameters in over-pressured zones. The majority of the techniques are based on shale behaviour, which typically exhibits a strong relationship between porosity and pore fluid pressure. However, carbonate rocks are stiffer and may contain over-pressures without any associated influence on porosity. Indeed, the application of common pore pressure prediction methods to carbonate rocks can yield large and potentially dangerous errors, even suggesting absences or decrease in abnormal pressure in zones of high magnitude over-pressure. In some cases, the hypothesises which been in the conventional methods seems to be flawed in some cases where pore pressure decreases by depth. In this research, a new method for effective stress calculation has been obtained using the compressibility attribute of reservoir rocks. In the case of over-pressure generation by undercompaction (as occurs in most clastic over-pressured sequences), pore pressure is dependent on the changes in pore space, which is a function of rock and pore compressibility. In simple terms, pore space decreases while the formation under goes compaction, and this imposes pressure on the fluid which fills the pores. A carbonate reservoir in a field in Iran has been investigated to establish pore fluid pressure generation mechanisms, and to attempt new methods for pore pressure prediction in carbonate rocks.
Publisher: SPE
Date: 16-04-2012
DOI: 10.2118/150835-MS
Abstract: Knowledge of pore fluid pressure is essential for safe drilling and efficient reservoir modelling. An accurate estimation of pore pressure allows for more efficient selection of casing points and a reliable mud weight design. Current commonly used methods of pore pressure prediction are based on the difference between a ‘normal trend’ in sonic wave velocity, formation resistivity factor (FRF), or d-exponent (a function of drilling parameters) and the observed value of these parameters in over-pressured zones. The majority of the techniques are based on shale behaviour, which typically exhibits a strong relationship between porosity and pore fluid pressure. However, carbonate rocks are stiffer and may contain over-pressures without any associated influence on porosity. Indeed, the application of common pore pressure prediction methods to carbonate rocks can yield large and potentially dangerous errors, even suggesting absences or decrease in abnormal pressure in zones of high magnitude over-pressure. In some cases, the hypothesises which been in the conventional methods seems to be flawed in some cases where pore pressure decreases by depth. In this research, a new method for effective stress calculation has been obtained using the compressibility attribute of reservoir rocks. In the case of over-pressure generation by undercompaction (as occurs in most clastic over-pressured sequences), pore pressure is dependent on the changes in pore space, which is a function of rock and pore compressibility. In simple terms, pore space decreases while the formation under goes compaction, and this imposes pressure on the fluid which fills the pores. Carbonate reservoirs in two fields in Iran have been investigated to establish pore fluid pressure generation mechanisms, and to attempt new methods for pore pressure prediction in carbonate rocks.
Publisher: MDPI AG
Date: 17-12-2018
DOI: 10.3390/GEOSCIENCES8120496
Abstract: The Abadan Plain Basin is located in the Middle East region which is host to some of the world’s largest oil and gas fields around the Persian Gulf. This basin is a foredeep basin to the southwest of the Zagros Fold-Thrust-Belt, bounded along its northern and eastern margins by the Dezful Embayment. Most of the rocks in this basin have been deposited in a carbonate environment, and existing fractures have made the formations a favourable place for hydrocarbon accumulations. The basin is enriched by oil and, therefore, gas reservoirs are few, and some of the explored reservoirs exhibit significant degrees of overpressure. This paper has compiled several aspects of the Abadan Plain Basin tectonics, structural geology and petroleum systems to provide a better understanding of the opportunities and risks of development activities in this region. In addition to the existing knowledge, this paper provides a basin-wide examination of pore pressure, vertical stress, temperature gradient, and wellbore stability issues.
Publisher: Elsevier
Date: 2021
Publisher: MDPI AG
Date: 19-02-2021
DOI: 10.3390/GEOSCIENCES11020098
Abstract: Alaska holds more than 68 billion barrels of proved oil reserves and more than 36.7 trillion cubic feet of proved natural gas reserves with some special conditions such as proximity to permafrost, making Alaskan petroleum reserves unique. The low temperature in shallow reservoirs prohibited hydrocarbons’ ideal maturation, thereby generating several heavy and viscous oil accumulations in this state. This also limits the enhanced oil recovery (EOR) options, leaving the thermal methods off the table to avoid permafrost thawing, which can cause wellbore collapse. Several solutions have been attempted for improving oil production from heavy and viscous oil in Alaska however, they have not yielded the desired recovery, and ultimate recovery factors are still less than the global average. One solution identified as a better alternative is using CO2 as an injecting fluid, alternated by water or mixed with other injectants. This paper provides a comprehensive overview of all studies on using CO2 for enhanced oil recovery purposes in Alaska and highlights common and unique challenges this approach may face. The suitability of CO2-EOR methods in the Alaskan oil pools is examined, and a ranking of the oil pools with publicly available data is provided.
Publisher: Elsevier
Date: 2021
Publisher: SPE
Date: 11-11-2012
DOI: 10.2118/156337-MS
Abstract: Pore pressure is a key parameter in controlling the well in terms of reservoir fluid pressure. An accurate estimation of pore pressure yields to better mud weight proposition and pressure balance in the bore hole. Current well known methods of pore pressure prediction are mainly based on the differences between the recorded amount and normal trend in sonic wave velocity, formation resistivity factor (FRF), or d-exponent (a function of drilling parameters) in overpressured zone. The majority of the techniques are based on the compaction of specific formation type which need localization or calibration. They occasionally fail to proper response in carbonate reservoirs. In this research, a new method for calculating the pore pressure has been obtained using the compressibility attribute of reservoir rock. In the case of overpressure generation by undercompaction (which is the case in most of the reservoirs), pore pressure is depended on the changes in pore space which is a function of rock and pore compressibility. In a simple way, pore space decreases while the formation undergoes compaction and this imposes pressure on the fluid which fills the pores. Generally, rock compressibility has minor changes over a specific formation, but even this small amount must be considered. Thus, the statistical tools should be used to distribute the compressibility over the formation. Therefore, based on the bulk and pore compressibility achieved from the special core analysis (SCAL) or well logs in one well, the pore pressure in the other locations of a formation could be predicted.
No related grants have been discovered for Vahid Atashbari.