Surfactant Flooding for EOR Using Sodium Lignosulfonate Synthesized from Bagasse

Surfactant injection is one of the types of chemical injections used in enhanced oil recovery (EOR) process. Surfactant can increase the interfacial tension between oil and water in the rock matrix. The surfactant used is an anionic surfactant, which is one of the lignosulfonate surfactants known as sodium lignosulfonate (SLS) surfactant derived from lignin. Bagasse is one of the raw materials having a high content of lignin (24–25%). The synthesized bagasse becomes lignosulfonate used as an isolation of lignin and transformed into sodium lignosulfonate by sulfonation process. Based on the characteristic test, the bagasse’s SLS surfactant has some qualified characteristics which are a good aqueous stability, clear solution and not causing turbidity, and capability to form middle-phase microemulsion with light oil. Synthesized SLS has a hydrophilic–lipophilic balance (HLB) value of 11.6 which can be classified as oil in water (O/W) emulsion. Middle-phase emulsion as a characteristic SLS surfactant affects the performance of the SLS surfactant injection. So the use of sodium lignosulfonate surfactant synthesized from bagasse is a challenge to be developed further as a surfactant flooding

Correlation between Phase Behavior and Interfacial Tension for Mixtures of Amphoteric and Nonionic Surfactant with Waxy Oil

Phase behavior tests in the surfactant screening process for EOR applications remain one of the relatively convenient ways to design an optimum surfactant formulation. However, phase behavior studies are unable to provide quantitative data for interfacial tension, which is one of the parameters that must be considered when selecting surfactants for EOR. Several studies related to the prediction of interfacial tension through phase behavior testing have been carried out. In this paper, the Huh correlation was used to estimate the interfacial tension value based on phase behavior tests. It was found that the current form of the Huh correlation may be applied for the below-to-optimum salinity condition. Furthermore, the constants of the equation vary depending on the surfactant type and mixtures. 

The Effect of Surfactant Characteristics on IFT to Improve Oil Recovery in Tempino Light Oil Field Indonesia

Water injection has been employed in the Tempino oil field since 1996. The current oil recovery factor is 35% of OOIP. Even though the pressure is still high, the oil production rate has declined rapidly and the water cut is approaching 89%. In order to mobilize  the  oil from the  reservoir  more effectively, surfactant flooding is one of the solutions that can reduce residual oil saturation. Interaction between crude oil and compatible surfactant generates microemulsion,  as an indication of low interfacial tension. Hence the oil is expected to move out of the pore throat easily. In this research, thirty types of surfactants  were evaluated. The hydrophilic  lipophilic  balance (HLB)  was calculated and  the  interfacial tension (IFT)  with the  reservoir fluid  was measured. HLB criteria were established as an indicator of low IFT, which was then tested for Berea core flooding. The results indicate that an HLB between approximately 2.7 and 3.1 (on Davies' Scale) or greater than 11.5 (on Griffin's Scale) gives  low IFT  (~10-3 dynes/cm).  This characteristic  is possesed by surfactant  ethoxy  carboxylate  with a  linear hydrophobic structure.  This surfactant produces a high incremental oil recovery according to Berea core flood tests. The AN2NS and AN3 surfactants recovered 90% and 86% of OOIP respectively

Surfactant-Polymer Coreflood Simulation and Uncertainty Analysis Derived From Laboratory Study

This paper presents a numerical simulation study on coreflood scale derived from a laboratory study conducted on light oil and water-wet sandstone samples from fields at Tempino and Kenali Asam, Sumatra, Indonesia. A rigorous laboratory study prompted a specified surfactant type among dozens of screened samples, i.e. AN3NS and AN2NS-M for Kenali Asam and Tempino, respectively. The coreflood scale numerical simulation study was performed using a commercial simulator, on the basis of the results from the laboratory study, at a constant temperature of 68°C, 0.3 cc/min injection rate and under 120 psia confining pressure. To get better recovery, the cores were tested using surfactant and polymer in a blended mode, containing 0.03% w/w polymer diluted in each field brine, which accommodated around 8000 ppm salinity. The most significant variable in the multiphase flow is the relative permeability curve, which is affected by interfacial tension (IFT) during waterflooding and surfactant-polymer (SP) flooding. This study shows that relative permeability will be shifted at ultra-low IFT (10-3 to 10-4 mN/m). This shifting phenomenon is governed by the interpolation parameter set, which implicitly represents the capillary number. Further work in matching the numerical results to the coreflood was conducted by changing the interpolation parameters

Rock Mineralogy Analysis of Airbenakat Formation to Map the Characteristics of the Reservoir Rocks in each Depositional Environment

The Airbenakat Formation is a sandstone reservoir which is one of the oil reservoirs located in Sumatra and is part of the South Sumatra Basin. The mineral composition of the sandstone reservoir in the Airbenakat Formation consists of quartz minerals as rock grains, clay as matrix and is often identified as cement, while carbonate as rock cement. Based on lithofacies observations, the depositional environment of the Airbenakat Formation consists of: Volcanic Alluvial Fan, Lake, Braid Bar, Braided Channel, Braid Deltaic Environment, Mud Flat, Tidal Sand Bar, Tidal Environment, Shallow Sea, and Deep Sea. This research was conducted on 2 (two) oil fields, namely MRP dan TPN which have different depositional environments but are included in the Airbenakat Formation as part of the South Sumatra Basin.The analyzes used in this study include X-Ray Diffraction (XRD) analysis, petrography, and Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM/EDX). Analysis of the mineralogical content of the Airbenakat Formation will assist to determine the performance of chemical injections such as injection of anionic surfactant. The anionic surfactant used for chemical injection in Airbenakat Formations will be optimal if the content of smectite and calcite minerals can be ascertained. The presence of smectite and calcite minerals will affect the results of anionic surfactant injection. This research shows the results of anionic surfactant injection on the presence of smectite and carbonate in the injected core

Lessons Learned in Interfacial Tension Prediction Using a Mixture of Sulfonate- and Ethoxylate-based Surfactants in a Waxy Oil-brine System

The chemical-enhanced oil recovery (CEOR) method is applied to change reservoir rock or fluid characteristics by injecting alkaline, surfactant, and polymer or a combination of two or three of the compounds. Surfactant flooding improves oil recovery by reducing the interfacial tension between oil and water. Selecting reservoir surfactants, especially microemulsions, requires careful screening. This study predicted waxy oil system interfacial tension using surfactant mixtures at below- and above-optimum salinity. To predict the interfacial tension, microemulsion types, HLB, ideal salinity, and HLD were used. The study predicted oil-surfactant-water interfacial tension using SAE, FEO, and their mixtures. We improved the Huh equation by adding a fitting parameter, β, to accommodate the transition from type III to type II microemulsions as salinity increases. With increasing salinity, anionic surfactant’s hydrophilic-hydrophobic interactions change, affecting the  values and surfactant layer thickness. This study improved hydrophilic-lipophilic deviation (HLDN) by establishing a fixed interval for nonionic surfactants. Van der Waals attraction,  values and interface surfactant layer thickness are connected, reflecting the fact that lower  values reduce interfacial tension better. This study also found that surfactant packing at the oil-water interface increases the order of the oil-solution ratio and the microemulsion values with polarity

Capacitance Resistance Clustered Model for Mature Peripheral Waterflood Performance Prediction & Optimization

Optimizing water injection rate distribution in waterflooding operations is a vital reservoir management aspect since water injection capacities may be constrained due to geographic location and facility limitations. Traditionally, numerical grid-based reservoir simulation is used for waterflood performance evaluation and prediction. However, the reservoir simulation approach can be time-consuming and expensive with the vast amount of wells data in mature fields. Capacitance Resistance Model (CRM) has been widely used recently as a data-driven physics-based model for rapid evaluation in waterflood projects. Even though CRM has a smaller computation load than numerical reservoir simulation, large mature fields containing hundreds of wells still pose a challenge for model calibration and optimization. In this study, we propose an alternative solution to improve CRM application in large-scale waterfloods that is particularly suitable for peripheral injection configuration. Our approach attempts to reduce CRM problem size by employing a clustering algorithm to automatically group producer wells with an irregular peripheral pattern. The selection of well groups considers well position and high throughput well (key well). We validate our solution through an application in a mature peripheral waterflood field case in South Sumatra. Based on the case study, we obtained up to 18.2 times increase in computation speed due to parameter reduction, with excellent history match accuracy

OPTIMASI PEMISAHAN LIGNIN AMPAS TEBU DENGAN MENGGUNAKAN NATRIUM HIDROKSIDA

Lignin atau zat kayu adalah salah satu zat komponen penyusun tumbuhan. Komposisi bahan penyusun ini berbeda-beda bergantung jenisnya. Lignin terutama terakumulasi pada batang tumbuhan berbentuk pohon dan semak. Pada batang, lignin berfungsi sebagai bahan pengikat komponen penyusun lainnya, sehingga suatu pohon bisa berdiri tegak (seperti semen pada sebuah batang beton). Lignin merupakan bahan baku pembentuk Lignosulfonat. Lignosulfonat adalah salah satu jenis surfaktan anionik yang dapat digunakan sebagai bahan baku injeksi dalam metoda Injeksi Surfaktan untuk meningkatkan perolehan produksi minyak pada industri perminyakan. Ampas tebu adalah salah satu bahan limbah yang di dalamnya masih terdapat lignin. Ampas tebu  adalah hasil samping dari proses ekstraksi cairan tebu. Ampas tebu yang dipergunakan adalah ampas tebu yang telah mengalami proses penggilingan ke lima kali dari proses pembuatan gula. Selama ini ampas tebu digunakan sebagai bahan bakar pabrik gula dan  pakan ternak. Dengan proses pemisahan lignin dari ampas tebu ini dapat memberi nilai tambah pemanfaatan ampas tebu sekaligus sebagai alternatif pengolahan ampas tebu sebagai limbah pabrik gula. Salah satu metoda yang digunakan untuk memisahkan lignin dari ampas tebu adalah dengan menggunakan reagen Natrium Hidroksida. Dalam penelitian ini proses hidrolisis lignoselulosa dari ampas tebu menjadi lignin menggunakan variasi konsentrasi natrium hidroksida (NaOH) dan variasi ukuran serbuk ampas tebu. Hasil lignin yang terbentuk dikarakterisasi dengan metode spektroskopi FTIR untuk menentukan gugus-gugus fungsi khas yang terdapat pada struktur lignin dan dibandingkan dengan spektrum FTIR lignin komersial standar sehingga dapat diketahui optimasi pemisahan lignin tersebut

Hasil Studi Laboratorium Penentuan Karakteristik Alamiah Surfaktan Natrium Lignosulfonat Dari Ampas Tebu Sebagai Fluida Injeksi Di Reservoir Minyak

Surfaktan Natrium Lignosulfonat (NaLS) dari ampas tebu merupakan salah satu pengembangan surfaktan lignosulfonat yang dibuat dari limbah nabati, yaitu adalah ampas tebu. Pada studi ini telah diperoleh hasil sintesa ampas tebu menjadi surfaktan lignosulfonat yang jika dikembangkan akan dapat menjadi alternatif surfaktan sebagai fluida injesi di reservoir minyak. Dari hasil penelitian dan pengujian yang telah dilakukan, surfaktan NaLS ampas tebu ini mempunyai kesamaan komponen dengan surfaktan lignosulfonat standar yaitu terdiri dari gugus ulur alkena, gugus ulur sulfonat, gugus tekuk karboksilat dan gugus tekuk ester. Berdasarkan analisis spektrum NMR, molekul monomer lignosulfonat tersebut mempunyai atom C, O, H dan S di dalam dengan jumlah atom C = 11, O = 8, H = 16, dan S = 1, sehingga rumus empiris monomer lignosulfonat adalah (C11H16O8S)n, dengan massa molekul relatif 308,06. Berdasarkan struktur monomer lignosulfonat ampas tebu, maka gugus-gugus fungsi dalam strukturnya dapat dikelompokkan sebagai gugus hidrofil atau gugus hidrofob dan dapat dihitung nilai HLB (Hidrofil-lipofilik Balance) yang dimiliki oleh surfaktan NaLS ampas tebu tersebut yaitu sebesar 11,62. Dengan nilai HLB ini maka surfaktan NaLS ampas tebu ini sesuai penggunaannya sebagai sistem tipe emulsi O/W (oil in water), yang berarti surfaktan tersebut larut dalam air dan dapat digunakan sebagai fluida injeksi

Wettability Alteration Induced by Surface Roughening During Low Salinity Waterflooding

Wettability alteration during low salinity waterflooding (LSW) is expected to be one of the prominent reasons for enhanced oil recovery. However, the underlying mechanisms of improved oil recovery in sandstone during LSW are not entirely clear. Thus, a series of experiments was carried out to investigate the underlying mechanisms that drive the wettability alteration. FTIR spectroscopy was combined with thermogravimetric analysis to quantify the amount of adsorbed hydrocarbon components in sandstone with various clay contents. Afterward, the time-dependent contact angle in fabricated sandstone substrate (RMS roughness 9.911.31) was observed with various clay and brine contents to monitor the wettability alteration during LSW. The existence of divalent ions (Ca2+ and Mg2+) was found to stabilize the sandstone and prevent it from swelling. Surprisingly, with the presence of divalent ions, the rate of contact angle change was insignificant (, even though a reduction of divalent ions occurred and the rate of contact angle change with the sole presence of NaCl was notably altered (. Furthermore, the presence of higher clay content showed an increased contact angle alteration. We propose that these phenomena are partially driven by macroscopic phenomena of clay swelling, which leads to surface roughening and enhances the water-wetness