scholarly journals Evaluasi Nilai Difusivitas Ion Kalsium & Magnesium pada Proses "Low Salinity Waterflood" di Batuan Berea

2018 ◽  
Vol 11 (2) ◽  
pp. 62
Author(s):  
Yusmardhany Yusuf ◽  
Suryo Purwono ◽  
Sang Kompiang Wirawan

In recent years Low Salinity Waterflood (LSW) had been supposed as trusty method to improve oil recovery and the most essential aspect is a alteration of divalent ion concentration in reservoir pore volume as a respon LSW. The objective of this paper are to find divalent diffusivity constant (Ca2+ and Mg2+) in berea sandstone by ionsmass conservation equation along with Atomic Absorption Spectroscopy (AAS) as validation. The study was conducted at 2 berea core having porosity : 0.235 and 0.230 and permeability : 661 mD and 550 mD, we use synthetic formation water accordance to "LN" field property. Experiment was treated by by diluting Ca2+ up to 79% from its original value and  by diluting Mg2+ up to 95% from its original value while other ion were maintained fit to their original value. As a result we got difusion constant 0.0620 cm2.min-1 and 0.2667 cm2.min-1for Ca2+ and Mg2+, respectively.

2020 ◽  
Vol 10 (11) ◽  
pp. 3752 ◽  
Author(s):  
Shabrina Sri Riswati ◽  
Wisup Bae ◽  
Changhyup Park ◽  
Asep K. Permadi ◽  
Adi Novriansyah

This paper presents a nonionic surfactant in the anionic surfactant pair (ternary mixture) that influences the hydrophobicity of the alkaline–surfactant–polymer (ASP) slug within low-salinity formation water, an environment that constrains optimal designs of the salinity gradient and phase types. The hydrophobicity effectively reduced the optimum salinity, but achieving as much by mixing various surfactants has been challenging. We conducted a phase behavior test and a coreflooding test, and the results prove the effectiveness of the nonionic surfactant in enlarging the chemical applicability by making ASP flooding more hydrophobic. The proposed ASP mixture consisted of 0.2 wt% sodium carbonate, 0.25 wt% anionic surfactant pair, and 0.2 wt% nonionic surfactant, and 0.15 wt% hydrolyzed polyacrylamide. The nonionic surfactant decreased the optimum salinity to 1.1 wt% NaCl compared to the 1.7 wt% NaCl of the reference case with heavy alcohol present instead of the nonionic surfactant. The coreflooding test confirmed the field applicability of the nonionic surfactant by recovering more oil, with the proposed scheme producing up to 74% of residual oil after extensive waterflooding compared to 51% of cumulative oil recovery with the reference case. The nonionic surfactant led to a Winsor type III microemulsion with a 0.85 pore volume while the reference case had a 0.50 pore volume. The nonionic surfactant made ASP flooding more hydrophobic, maintained a separate phase of the surfactant between the oil and aqueous phases to achieve ultra-low interfacial tension, and recovered the oil effectively.


2018 ◽  
Vol 24 (8) ◽  
pp. 40
Author(s):  
Hussain Ali Baker ◽  
Kareem A. Alwan ◽  
Saher Faris Fadhil

Smart water flooding (low salinity water flooding) was mainly invested in a sandstone reservoir. The main reasons for using low salinity water flooding are; to improve oil recovery and to give a support for the reservoir pressure. In this study, two core plugs of sandstone were used with different permeability from south of Iraq to explain the effect of water injection with different ions concentration on the oil recovery. Water types that have been used are formation water, seawater, modified low salinity water, and deionized water. The effects of water salinity, the flow rate of water injected, and the permeability of core plugs have been studied in order to summarize the best conditions of low salinity water flooding. The result of this experimental work shows that the water without any free ions (deionized water) and modified low salinity water have improved better oil recovery than the formation water and seawater as a secondary oil process. The increase in oil recovery factor related to the wettability alteration during low salinity water flooding which causes a decrease in the interfacial tension between the crude oil in porous media and the surface of reservoir rocks. As well as the dissolution of minerals such as calcite Ca+2 was observed in this work, which causes an increase in the pH value. All these factors led to change the wettability of rock to be more water-wet, so the oil recovery can be increased.  


Author(s):  
Seyyed Hayan Zaheri ◽  
Hossein Khalili ◽  
Mohammad Sharifi

Water injection has been known as a conventional approach employed for years in order to achieve higher oil recovery from oil reservoirs. Since the last decade many researchers conducted on the water injection assessment suggested that low salinity water flooding can be an effective flooding mechanism and it can be used as an enhanced oil recovery method. Several examinations were conducted to identify governing mechanisms entailed in oil extraction and the effect of salinity and different types of ionic contents contained in Formation Water (FW) and injected fluid. This study is dedicated to address the influence of salinity and different types of ionic contents contained in formation water and injected fluid on incremental oil recovery. For this purpose, fluid–fluid and rock–fluid interaction were investigated especially for evaluating the effect of calcium ions in the formation water and sulfate ions in the injected water. Several experiments were carried out including core-flooding, contact angle, and imbibition tests. While former researchers concluded that reducing the salinity of injected water causing a decrease in ionic strength may lead to a greater oil recovery, in this research, we showed that these statements are not necessarily true. It was observed that existence of the high calcium concentration in the formation water would cause significant effect on wettability status of rocks and final oil recovery during low salinity water injection. This process is mainly due to rock wettability alteration. Wettability alteration mechanism in carbonate rocks is explained through interaction between rock and fluid composition. The results indicate the decisive role of calcium ions in the formation water at all stages from aging in oil to primary and secondary recovery. In addition to that, it was observed that more sulfate ion concentration in the injected water enhances rock wettability alteration.


2015 ◽  
Vol 1 (2) ◽  
pp. 107
Author(s):  
Charlena ◽  
Henny Purwaningsih ◽  
Tina Rosdiana

  ABSTRACT Natural zeolite reserves are spread in Indonesia, but they are not yet used optimally. Generally, natural zeolite have poor crystalline, various pore size, low catalytic activity, and high contaminant. Natural zeolite need to be activated and modified before it can be used. The objectives of this research were to activite the natural zeolite that already got acid and thermal treatments and to characterize it and catalytic activity was tested in interesterification reaction. Fourier transformation infrared (FTIR) spectra showed that the structure of natural zeolite activated by acid and thermal  (NZAT) treatments were damaged. While, natural zeolite structure activated with acid (natural zeolite acid /NZA) did not show significant different to natural zeolite (NZ). Result of Si/Al ratio analysis showed that Si/Al ratio NZA higer than Si/Al ratio NZAT. The result of cation analysis by atomic absorption spectroscopy shoed that the general content of Na, K, Fe and Ca in the catalyst decreased because of acid and thermal treatments. Surface area and pore volume increased by the treatments. Catalytic activity of NZA in interesterification reaction gave a white cork product and in yield 35.78 %. Keywords : natural zeolite activated, catalytic activity, FTIR. 


2021 ◽  
Author(s):  
H. Zakyan

Enhanced Oil Recovery (EOR) come up with promising result to endure mature fields production performance and has been proven worldwide in many various methods. Recently, Low Salinity Water Injection evolves as a simply operation and relatively low cost EOR method with wide of research and implementation seem to be proved effective in the past decades. Some laboratory tests have indicated that injecting low salinity water can improve conventional waterflood performance by 5 – 20%. Hence, it introduces a promising idea that Low Salinity Water Injection should be implemented to mature fields in Indonesia for EOR activity. This paper will focus on determining the optimum salt concentration of injection water for low salinity water injection. Low salinity water injection in this study will be acted as a secondary recovery method. The production performance as a result of low salinity water injection was acquired by numerical simulation using tNavigatorTM Simulator. This simulation will be conducted in Tangai Structure at Sukananti Field, South Sumatera Basin, Indonesia with Talang Akar Formation reservoir target. The simulation is conduct with the constraint injection rate of 1,340 BWIPD. The low salinity water is designed by dilution of salt concentration from formation water with 18,000 ppm of concentration. In this case, the sensitivity of low salinity water, mainly amount of salt concentration design, will be conducted in the simulation consisting of using formation water as scenario’s base case and various low salinity water designs which will be limited until 10x of dilution (1,800 ppm). The result of this study concluded that Low Salinity Water Injection achieved more oil recovery than conventional waterflood did. This incremental is caused by wettability alteration due to of salt concentration changes which attract the clay minerals in reservoir through many complex mechanisms. The simulation result shows that injection water with 10x dilution (1,800 ppm) is chosen as an optimum salt concentration design, which gives the best result with gains additional oil recovery and recovery factor about of 118,8 MSTB and 4,9% respectively from a scenario by injecting formation water (18,000 ppm).


2021 ◽  
Author(s):  
Felix Feldmann ◽  
Emad W. Al-Shalabi ◽  
Waleed AlAmeri

Abstract Low-salinity waterflooding is a relatively simple and cheap improved oil recovery technique in which the reservoir salinity is optimized to increase oil recovery. Multivalent ion enriched as well as diluted brines have shown promising potential to increase oil production over conventional waterflooding. While the literature generally acknowledges that low-salinity improves oil recovery, the physical mechanisms behind low-salinity effects are still controversial. Surface charge change refers to a low-salinity mechanism in which modified brine is believed to cause a re-equilibrium of the carbonate surface potential. As a result of surface charge change, the rock wettability alters towards a more water-wetting state. This experimental study combines zeta potential, spontaneous imbibition, and contact angle measurements to highlight the effect of carbonate minerals on surface charge change. Initially, zeta potential measurements were conducted to compare the impact of five carbonate minerals (Indiana Limestone, Edward Limestone, Reservoir Limestone, Austin Chalk, and Silurian Dolomite) and brine compositions (Formation-water, Sea-water, and Diluted-sea-water) on carbonate surface charge. Moreover, the impact of potential determining ions (calcium, magnesium, and sulfate) on the mineral surface charge was investigated. The effect of carbonate minerals on spontaneous oil recovery was investigated by comparing the spontaneous imbibition of Formation-water, Sea-water, and Diluted-sea-water into the five carbonate minerals. Moreover, the wettability alteration during the spontaneous imbibition tests was quantified by conducting contact angle measurements. The brine-mineral zeta potential measurements were positive for Formation-water, slightly negative for Sea-water, and strongly negative for Diluted-sea-water. While calcium and magnesium ions promoted stronger positive electrical potentials, sulfate ions caused a zeta potential reduction. The magnitude of surface charge change was significantly different for the five tested carbonate minerals. Under the presence of Diluted-sea-water, the zeta potential measurements of Indiana Limestone and Austin Chalk resulted in strong negative electrical potentials. Reservoir Limestone and Edward Limestone showed less negative zeta potentials, while Silurian Dolomite and Diluted-sea-water resulted in slightly negative zeta potential results. Compared to Formation-water, Sea-water, and particularly Diluted-sea-water caused significant spontaneous oil recovery. The high spontaneous oil recovery of Diluted-sea-water and Indiana Limestone and Austin Chalk correlated with strong negative brine-mineral zeta potentials. Moderate spontaneous oil recovery was observed for the slightly negative zeta potential Sea-water and limestone/chalks systems. The contact angle measurements showed oil-wet contact angles under the presence of Formation-water, while the introduction of Sea-water and Diluted-sea-water promoted stronger water-wet contact angles. This work is one of the very few studies that investigates the effect of carbonate rock mineralogy on surface charge change and spontaneous oil recovery.


2020 ◽  
Vol 17 (3) ◽  
pp. 156-164
Author(s):  
Tinuola H. Udoh

In this paper, the effect of temperature on low salinity brine and combined low salinity enzyme oil recovery processes in sandstone rock sample was experimentally investigated. The core flooding displacement tests were conducted with the injection of the enzyme in post-tertiary mode after secondary high salinity brine and tertiary low salinity brine injection processes. Effluents analyses of each of the flooding were carried out and used to evaluate the effect of temperature on rock-fluid interactions and enhanced oil recovery processes. The results showed that tertiary low salinity brine injection and post-tertiary enzyme injection increased recovery by 2.4-8.72% over the secondary high salinity brine flooding at 25 oC. Also, increase in oil recovery (0.57-13.18%) was observed with increase in the system temperature from 25 oC to 70 oC. Furthermore, the effluent of the 70 oC flooding was associated with the earliest low salinity brine ionic breakthrough front at 10 injected pore volume, while the 25 oC flooding breakthrough front occurred at 22 pore volume. However, no obvious effect of temperature on pH of the effluents was observed with all the floodings, but temperature effects were observed with the conductivity and ionic concentrations of all the effluents as evident by varied breakthrough times. Hence, the observed increased recovery in this study is attributable to combined effects of electric double-layer expansion, oil viscosity reduction and interfacial tension reduction. This novel study of the combined low salinity enzyme injection process is significant for the design of enzyme enhanced oil recovery processes. Keywords: Enhanced oil recovery, enzyme, sandstone, low salinity, core flooding, temperature.


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