Research Paper
Petroleum Engineering
Yaser Ahmadi
Abstract
Recently nanoparticles are used for improving the volume of oil and gas production and Enhanced Oil Recovery (EOR) purposes. Based on our recent researches, using nanoparticles such as Silica and Calcium oxide has a good potential for changing mechanisms in the porous media such as interfacial tension ...
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Recently nanoparticles are used for improving the volume of oil and gas production and Enhanced Oil Recovery (EOR) purposes. Based on our recent researches, using nanoparticles such as Silica and Calcium oxide has a good potential for changing mechanisms in the porous media such as interfacial tension and wettability. For finding the application of nanoparticles in the porous media, low permeability carbonate plugs were selected, and two main steps were used , including 1) Using CaO and SiO2 nanoparticles for wettability alteration, interfacial tension reduction, and improving fluid flow through porous media 2) Surveying the application of nanoparticles on the water alternative gas (NCs assisted WAG) test. The Zeta potential amounts are stable at condition of -56.4±2 mV and -44.0±3 mV for Calcium oxide and Silica nanoparticles, respectively at optimum nanoparticles concentration of 15 ppm. Calcium oxide and Silica nanoparticles have effectively altered the wettability from oil-wet to water-wet by surveying the intersection of two-phase relative permeability. Moreover, CaO nanoparticles had better performance in low permeability carbonate porous media than SiO2 nanoparticles with regards to wettability alteration to water wet. Based on the results and better version of CaO, it was selected for performing NCs assisted WAG tests at WAG ratios of 1:1, 40 ℃, and 15 ppm.The recovery factor was increased from 42.9 % to 73 % in the presence of CaO during performing NCs assisted WAG tests, and residual oil saturation was decreased from 40.9 % to 19.4 %.
Research Paper
Petroleum Engineering – Drilling
Abdeslem Leksir
Abstract
Column final test facing new challenge, in addition to casing burst/collapse limitations; buckling occurrence creates serious problems. Practically, in case of slight gap between mud and slurry densities, buckling initiation is inevitable. Casing elongation, bending and buckling detailed, to define column ...
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Column final test facing new challenge, in addition to casing burst/collapse limitations; buckling occurrence creates serious problems. Practically, in case of slight gap between mud and slurry densities, buckling initiation is inevitable. Casing elongation, bending and buckling detailed, to define column behavior while testing. Buckling influences on slurry pointed out too, and compared to column without test. New cement quality indicator is proposed, tested and validated via logging of wells drilled in different regions. Results generalized to cover other situations rather than heavy sections. Gas migration region, depleted reservoir, weak zones are all examined. Registrations confirm the appearance of buckling either while pumping slurry or pressure testing. New modified casing selection method conjointly with updated numerical technique proposed to prevent buckling. Experimental and simulation findings confirm the reliability of the proposed technique.
Research Paper
Petroleum Engineering – Reservoir
Seyed Reza Shadizadeh; Amin Derakhshan
Abstract
Oil recovery from oil wet carbonate rock is a big challenge in oil industry. In the present study, the influence of natural surfactant Hawthorn leaves extract (HLE) on oil recovery from carbonate rock is investigated. Two chemical surfactants include Sodium dodecyl sulfate (SDS) and Dodecyl tri methyl ...
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Oil recovery from oil wet carbonate rock is a big challenge in oil industry. In the present study, the influence of natural surfactant Hawthorn leaves extract (HLE) on oil recovery from carbonate rock is investigated. Two chemical surfactants include Sodium dodecyl sulfate (SDS) and Dodecyl tri methyl ammonium bromide (DTAB) were used for validation and comparison oil recovery with new natural surfactant HLE. Wettability alteration test using contact angle method, interfacial test (IFT) using pendant drop and core flooding were employed to investigate the behavior of the surfactants on oil recovery. Experimental results show the Critical Micellar Consentration (CMC) point of different concentrations of HLE, SDS and DTAB solution occurred at 3.25, 3 and 4.06 wt. %, respectively. The natural surfactant HLE was more effective than other chemical surfactant (SDS and DTAB) at CMC point in wettability alteration. As observed the contact angle of carbonate pellet and the HLE at CMC point was 86 degrees and this angle for SDS and DTAB were 112 and 92 degrees, respectively. Core flooding results show that oil recovery factor was improved from 37% with water flooding to 47.6 with SDS; 56.2% with DTAB and 54.7% with HLE. The results prove that; this new natural surfactant (HLE) can be used as a novel surfactant for chemical enhanced oil recovery process in carbonate oil reservoirs. HLE has beneficial effects in oil recovery because of its environment friendly compare to SDS and DTAB.
Research Paper
Mechanical Engineering
Hadi eskandari; Moslem Ghanbari
Abstract
The present study deals on the geometry effects of the spherical pressure vessel(SPV) and the crack configuration on the variation of the stress intensity factor (SIF) through the crack line. The pressurized vessel is subjected to the pressure and thermal gradient (thermo-mechanical loading). The 3D ...
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The present study deals on the geometry effects of the spherical pressure vessel(SPV) and the crack configuration on the variation of the stress intensity factor (SIF) through the crack line. The pressurized vessel is subjected to the pressure and thermal gradient (thermo-mechanical loading). The 3D analysis of defected thick-walled pressurized sphere vessel is done using the numerical Finite Element Method (FEM). This work covers a wide range of the crack configurations in vessels with different geometries. The effect of the various parameters such as thermal gradient, RO/Ri, a/c and a/t on the variation of the dominant first mode of SIF through the crack front is studied. The obtained SIF’s are compared with the mechanical loading results (in the absence of the thermal gradient). The results show that parameters such as the aspect ratio of the crack, the ratio of the crack depth, the pressure vessel wall thickness and also the temperature gradient have significant effects on the distribution of the SIF through the crack line. It can be seen that the thermo-mechanical condition is more critical.
Research Paper
Petroleum Engineering – Exploration
Mehrdad Safarpour; Mohammad Ali Riahi; Mehran Rahimi
Abstract
The main purpose of this paper is to estimate and evaluate the petrophysical properties of the Ghar Formation in the Hindijan and Bahregansar oilfields using a combination of seismic and well logs data. In this study, following a step-by-step regression approach: first; sonic, density, and, porosity ...
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The main purpose of this paper is to estimate and evaluate the petrophysical properties of the Ghar Formation in the Hindijan and Bahregansar oilfields using a combination of seismic and well logs data. In this study, following a step-by-step regression approach: first; sonic, density, and, porosity well-log data are collected. Second; seismic attributes, including amplitude, phase, frequency, and acoustic impedance are extracted from the seismic lines intersecting the wellbore locations. Then, using the MFLN and PNN intelligent systems, a relationship between porosity, shale volume, saturation, and seismic attributes is established. Using this relationship, the physical and petrophysical properties of the reservoir in the Ghar Formation are estimated and evaluated. We estimated the reservoir porosity between 15% and 20%, which is higher in the Hendijan oilfield as compared to the Bahregansar oilfield. The amount of water saturation in the Ghar formation varies between 25 and 30 percent. On the other hand, the amount of clay content and shale volume of the Ghar Formation in the Hendijan field is higher than that of the Bahregansar oil field.
Research Paper
Petroleum Engineering – Exploration
Bahram Alizadeh; Zollfaghar Eivazi Nezhad; Majid Alipour
Abstract
In this study, the hydrocarbon potential and depositional environments of the Coniacian Laffan Formation were investigated in the Binak Oilfield, SW Iran. With an average thickness of 80 meters, the Laffan Formation consists mainly of gray shales and thin argillaceous limestones in the study area. In ...
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In this study, the hydrocarbon potential and depositional environments of the Coniacian Laffan Formation were investigated in the Binak Oilfield, SW Iran. With an average thickness of 80 meters, the Laffan Formation consists mainly of gray shales and thin argillaceous limestones in the study area. In order to investigate the hydrocarbon potential, 22 cutting samples from 5 wells of the Binak Oilfield were analyzed by both Rock-Eval 6 pyrolysis and organic petrographic techniques. The HI versus Tmax diagrams indicated a mixed type II/III kerogen with maturity corresponding to early stages of the oil window (Tmax ≈ 435 ˚C). In addition, plots of S1+ S2 versus TOC were consistent with a weak to excellent hydrocarbon potential for the Laffan Formation. Organic petrographic techniques, on the other hand, indicated that the main organic constituents of the Laffan Formation are inertinite and bituminite with subordinate amounts of amorphous organic matter (AOM). In other words, the contained organic matter was mainly composed of inertinite and lacked significant hydrocarbon potential. Abundance of inertinite along with conspicuous absence of vitrinite macerals in the studied samples suggested that the Laffan Formation was deposited under sub-oxic marine conditions. Furthermore, the presence of bituminite in the studied samples greatly influenced the Rock-Eval pyrolysis readings. Thus, geochemical evaluation of the Laffan Formation using only Rock-Eval pyrolysis data may lead to erroneous interpretations. Therefore, combination of Rock-Eval and organic petrographic methods is deemed necessary for reliable geochemical evaluation of the Laffan Formation. The results of this study can be useful for better understanding of the Cretaceous hydrocarbon system in the study area.
