scholarly journals Capillary desaturation curve: does low salinity surfactant flooding significantly reduce the residual oil saturation?

Author(s):  
Davood Zivar ◽  
Peyman Pourafshary ◽  
Nikoo Moradpour

AbstractDifferent oil displacement experiments conducted on sandstone and carbonate samples show that low salinity water (LSW) injection can reduce the residual oil saturation (ROS). Recently, surfactant flooding (SF) in combination with low salinity water (known as low salinity surfactant (LSS) flooding) is proposed as a potentially promising hybrid enhanced oil recovery (EOR) process. A lower ROS is reported for a LSS process compared to that seen in SF or with LSW at the same capillary number. The capillary desaturation curve (CDC) is a well-known tool to study the effect of viscous and capillary forces on ROS for different EOR techniques. In this study, ROS data of various LSW, SF, and LSS flooding experiments at different capillary numbers are collected to develop a CDC to analyze the performance of the hybrid LSS method. This can help to analyze the effect of the hybrid method on an extra improvement in sweep efficiency and reduction in residual oil. A lower ROS is observed for LSS compared to LSW and SF in the same capillary number range. Our study shows different behaviors of the hybrid method at different ranges of capillary numbers. Three regions are identified based on the capillary number values. The difference in ROS is not significant in the first region (capillary number in the range of 10−7–10−5), which is not applicable in the presence of surfactant due to the low interfacial tension value. A significant reduction in ROS is observed in the second region (capillary number in the range of 10−5–10−2) for LSS compared to SF. This region is the most practical range for SF and LSS flooding. Hence, the application of LSS provides a noticeable benefit compared to normal EOR techniques. In the third region (capillary numbers greater than 10−2), where the surfactant flooding is a better performer, the difference in ROS is negligible.

2021 ◽  
Author(s):  
Julfree Sianturi ◽  
Bayu Setyo Handoko ◽  
Aditya Suardiputra ◽  
Radya Senoputra

Abstract Handil Field is a giant mature oil and gas field situated in Mahakam Delta, East Kalimantan Indonesia. Peripheral Low Salinity Water injection was performed since 1978 with an extraordinary result. The paper is intending to describe the success story of this secondary recovery by low salinity water injection application in the peripheral of Handil field main zone, which successfully increased the oil recovery and brought down the remaining oil saturation beyond the theoretical value of residual oil saturation number. Water producer wells were drilled to produce low salinity water from shallow reservoirs 400 - 1000 m depth then it was injected to main zone reservoirs where the main accumulation of oil situated. This low salinity water reacted positively with the rock properties and in-situ fluids which was described as wettability alteration in the reservoir. It is related to initial reservoir condition, connate water saturation, rock physics and connate water salinity. This peripheral scheme then observed having the sweeping effect on top of pressure maintenance due to long period of injection. The field production performance was indicating the important reduction of residual oil saturation in some reservoirs with continuous low salinity water injection. From static Oil in Place calculation, some reservoirs have high current oil recovery up to 80%. This was proved by in situ residual oil saturation measurement which was performed in 2007 and 2011. It was indicating the low residual saturation as low as 8% - 15%. This excellent result was embraced by a progressive development plan, where water flooding with pattern and chemical injection will be performed later on. The continuation of this peripheral injection is in an on-going development with patterns injection which is called water flooding development. An important oil recovery can be achieved with a simple scheme of low salinity injection, performed in a close network injection, where the water treatment is simple yet significant oil gain was recovered. This innovation technique brings more revenue with less investment compared to chemical EOR injection.


2021 ◽  
Author(s):  
J. Sianturi

Handil Field is a giant mature oil and gas field situated in Mahakam Delta, East Kalimantan Indonesia. Peripheral Low Salinity Water injection was performed since 1978 with extraordinary results. This paper describes the success story of this secondary recovery by low salinity water injection application in the peripheral of Handil field main zone, which successfully increased the oil recovery and brought down the remaining oil saturation beyond the theoretical value of residual oil saturation. Water producer wells were drilled to produce low salinity water from shallow reservoirs 400 - 1000 m depth then it was injected to main zone reservoirs where the main accumulation of oil is situated. This low salinity water reacted positively with the rock properties and in-situ fluids which is described as wettability alteration in the reservoir. It is related to initial reservoir condition, connate water saturation, rock physics and connate water salinity. This peripheral scheme then observed having the sweeping effect on top of pressure maintenance due to long period of injection. The field production performance was indicating the important reduction of residual oil saturation in some reservoirs with continuous low salinity water injection. From static Oil in Place calculation, some reservoirs have high current oil recovery up to 80%. This was proved by in situ residual oil saturation measurement which was performed in 2007 and 2011. It was indicating the low residual saturation as low as 8% - 15%. This excellent result was embraced by a progressive development plan, where water flooding with pattern and chemical injection will be performed later on. The continuation of this peripheral injection is in an on-going development with patterns injection which is called water flooding development. An important oil recovery can be achieved with a simple scheme of low salinity injection, performed in a close network injection, where the water treatment is simple yet significant oil gain was recovered. This innovation technique brings more revenue with less investment compared to chemical EOR injection.


2018 ◽  
Author(s):  
Hasan N. Al-Saedi ◽  
Ali K. Alhuraishawy ◽  
R. E. Flori ◽  
P. V. Brady ◽  
P. Heidari ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Emad Waleed Al-Shalabi ◽  
Kamy Sepehrnoori ◽  
Gary Pope

Low salinity water injection (LSWI) is gaining popularity as an improved oil recovery technique in both secondary and tertiary injection modes. The objective of this paper is to investigate the main mechanisms behind the LSWI effect on oil recovery from carbonates through history-matching of a recently published coreflood. This paper includes a description of the seawater cycle match and two proposed methods to history-match the LSWI cycles using the UTCHEM simulator. The sensitivity of residual oil saturation, capillary pressure curve, and relative permeability parameters (endpoints and Corey’s exponents) on LSWI is evaluated in this work. Results showed that wettability alteration is still believed to be the main contributor to the LSWI effect on oil recovery in carbonates through successfully history matching both oil recovery and pressure drop data. Moreover, tuning residual oil saturation and relative permeability parameters including endpoints and exponents is essential for a good data match. Also, the incremental oil recovery obtained by LSWI is mainly controlled by oil relative permeability parameters rather than water relative permeability parameters. The findings of this paper help to gain more insight into this uncertain IOR technique and propose a mechanistic model for oil recovery predictions.


2021 ◽  
Vol 6 (1) ◽  
pp. 40-46
Author(s):  
A. G. Skripkin ◽  
I. N. Koltsov ◽  
S. V. Milchakov

The paper presents the results of laboratory studies of polymer-surfactant flooding on core samples of different permeability. The obtained data are used in hydrodynamic modeling. Experimental studies included: • study of the dynamics of oil displacement, plotting the dependence of the residual oil saturation on the surfactant concentration – interfacial tension at the interface of the surfactant-oil solution; • comparative experimental studies of residual oil saturation when oil is displaced by surfactant compositions of various manufacturers; • comparative studies of phase permeability in flood experiments for the filtration of oil and water, oil and polymer-surfactant solution at different ratios in the flow.


2021 ◽  
pp. 168-176
Author(s):  
S. V. Kostyuchenko ◽  
N. A. Cheremisin

The article presents the author's formulas for calculating the residual oil saturation and the end points of relative phase permeabilities that dynamically depend on the filtration rate of reservoir fluids and capillary numbers. The dependences of the residual oil saturation and the end points of the phase permeabilities on the capillary number are investigated and described. An element of a five-point system for the development of an oil deposit case study shows the possibility of calculating oil targets using dynamic phase permeabilities. The difference between the model with static relative phase permeabilities and the model with dynamic phase permeabilities should be stressed. The text gives valuable information on the dependence of the simulation results on the parameters of the nonlinearity of the filtration processes with the traditional filtration-capacitance properties of the oil deposit model unchanged.


2020 ◽  
Vol 2 (11) ◽  
Author(s):  
Meysam Nourani ◽  
Thomas Tichelkamp ◽  
Bartlomiej Gaweł ◽  
Jens Norrman ◽  
Gisle Øye

AbstractThe focus of this study was the experimental determination of surfactant adsorption during low salinity water injection combined with surfactant flooding (LSW-SF) into an oil reservoir and development of an analytical model to predict this adsorption. The experimental model used was surfactant adsorption on silica and aluminosilicate coated quartz crystal surfaces in a quartz crystal microbalance (QCM), taking into consideration different surfactant concentrations, different surfactants, and the effect of different oils. In a previous study, the authors developed a method for determining the oil desorption from surfaces in QCM measurements. In this method the frequency decrease due to surfactant adsorption was determined experimentally by carrying out the blank measurements, and the role of the oil in the surfactant adsorption process was neglected. Therefore, in the developed calculation procedure for simplicity and practicality, it was assumed that the surfactant adsorption is independent of the oil properties. The analytical solution of the developed theoretically model in this study and the associated QCM experiments with different oils showed that taking into account the role played by the oil, it was possible to predict the difference in surfactant adsorptions with different type of oils, and there is a good agreement between analytical and experimental results. The results of the model reveal that surfactant\oil replacement on silica surfaces increased with increasing concentration of surfactant on silica surfaces. On the other hand, it decreased on aluminosilicate crystals with increasing surfactant concentrations.


2019 ◽  
Vol 130 (3) ◽  
pp. 731-749 ◽  
Author(s):  
Takashi Akai ◽  
Amer M. Alhammadi ◽  
Martin J. Blunt ◽  
Branko Bijeljic

Abstract We demonstrate how to use numerical simulation models directly on micro-CT images to understand the impact of several enhanced oil recovery (EOR) methods on microscopic displacement efficiency. To describe the physics with high-fidelity, we calibrate the model to match a water-flooding experiment conducted on the same rock sample (Akai et al. in Transp Porous Media 127(2):393–414, 2019. 10.1007/s11242-018-1198-8). First we show comparisons of water-flooding processes between the experiment and simulation, focusing on the characteristics of remaining oil after water-flooding in a mixed-wet state. In both the experiment and simulation, oil is mainly present as thin oil layers confined to pore walls. Then, taking this calibrated simulation model as a base case, we examine the application of three EOR processes: low salinity water-flooding, surfactant flooding and polymer flooding. In low salinity water-flooding, the increase in oil recovery was caused by displacement of oil from the centers of pores without leaving oil layers behind. Surfactant flooding gave the best improvement in the recovery factor of 16% by reducing the amount of oil trapped by capillary forces. Polymer flooding indicated improvement in microscopic sweep efficiency at a higher capillary number, while it did not show an improvement at a low capillary number. Overall, this work quantifies the impact of different EOR processes on local displacement efficiency and establishes a workflow based on combining experiment and modeling to design optimal recovery processes.


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