Laboratory core flooding experiments using Bio surfactant and

Laboratory core flooding experiments using Bio -surfactant and molasses: Implications for Microbial EOR Mohammad Bahar, Keyu Liu, Abdul Rashid , Xiaofang Wei, Tara Sutherland, Xiaoyi Wang, Manzur Ahmed, Phil Hendry, Dongmei Li, Se Gong, Herbert Volk, S. Razak, Wan Ata, A Azhan, M. Rizal CSIRO Wealth from Ocean Flagship and Petronas Research

Outline • Background • Objectives • Materials and methods • Results and discussion • Conclusions 30 th IEA Annual Workshop and symposium on EOR -Canberra

Oil Recovery Mechanisms CONVENTIONAL RECOVERY PRIMARY RECOVERY SECONDARY RECOVERY Natural Flow Artificial Lift (Pump, Gas Lift, etc. ) Waterflood Pressure Maintenance (Water, Gas Reinjection) EOR TERTIARY RECOVERY Thermal 30 ththe IEA Annual symposium on. Apr EOR -Canberra Adapted from Oil Workshop & Gasand. Journal, 23, 1990 Solvent Chemical MEOR Other

EOR vs. Permeability EOR Method Permeability (md) 100 10 Hydrocarbon Miscible Nitrogen and Flue Gas CO 2 Miscible Surfactant Polymer 1, 000 Not critical if uniform High enough for good injection Polymer Alkaline Fireflood Steam Drive MEOR Dr. Larry Lake, Oilfield Review (Jan. 1992) Good Possible Fair Difficult Not Feasible 30 th IEA Annual Workshop and symposium on EOR -Canberra

Oil Gravity vs. EOR Methods 0 10 Oil Gravity o. API 20 30 40 50 N 2 & Flue Gas Hydrocarbon CO 2 - Miscible Immiscible Gas Alkaline/Surfactant/Polymer Flooding Gel Treatments MEOR Steam Flooding Mining (Modified from J. J. Taber, F. D. Martin & R. S. Seright, 1997) 30 th IEA Annual Workshop and symposium on EOR -Canberra 60

What is MEOR and its Potential on EOR? • Microbes can be introduced into oil reservoirs, and/or indigenous microbes can be stimulated with nutrients. Potentials: • Changing fluid properties such as Density, Viscosity, composition and IFT • Changing the rock properties such as wettability , permeability and relative permeability • Changing conditions of system (pressurize, 30 th IEA Annual Workshop and symposium on EOR -Canberra

Background: Can MEOR be a successful method for EOR? Initial With biosurfactant (above CMC) S. M. Farouq Ali- University of Calgary-2003 30 th IEA Annual Workshop and symposium on EOR -Canberra

Overview of CSIRO’s MEOR project Microbiology Microbial physiology Microbial metabolisms Isolation and culture Modelling Analyse/verify experimental results Build predictive model for MEOR Build reservoir model for field trial Organic Geochemistry Develop analytical protocol identify/quantify metabolites before and after Microorganisms treatments Measuring fluid physical properties, such as density, viscosity and IFT Measuring rock physical properties K, Krw, Kro, Measuring EOR 30 th IEA Annual Workshop and symposium on EOR -Canberra

Objectives • Monitor changes in oil and water physical properties after culture experiments • Detect and quantify various by-products - Gases - Bio-surfactants - Acids - Co-biosurfactants - Polymer - Oil Degradation • Select suitable nutrients to stimulate microbial growth and production of metabolites leading to MEOR • Undertake core flooding experiments 30 th IEA Annual Workshop and symposium on EOR -Canberra

Material and methods • Reservoir fluids from Off-shore Malaysian oilfield - Depth: ~ 720 m - Temperature: 50ºC - Salinity: 2. 3 % - Mature, high water cut - Reservoir Pressure: 940 Psia 30 th IEA Annual Workshop and symposium on EOR -Canberra

Experiment : Core Flooding Setup 30 th IEA Annual Workshop and symposium on EOR -Canberra

Experimental sequences Water Oil Water Molasses Water 30 th IEA Annual Workshop and symposium on EOR -Canberra Core Holder Measuring volume of Water Oil Gas

Effects of biosurfactant on water densities No effects 30 th IEA Annual Workshop and symposium on EOR -Canberra

Effects of bio-surfactant on viscosity of Bokor formation water (104 LS) H 2 O viscosity increases with BS concentrations 30 th IEA Annual Workshop and symposium on EOR -Canberra

Effect of bio-surfactant (Surfactin) on IFT (104 LS) at 50 °C 940 psi 30 th IEA Annual Workshop and symposium on EOR -Canberra

MEOR core flooding results Swir=14%; Primary oil recovery: 74. 4% Soir=25. 6%; incremental EOR: 4. 1% MEOR Sor=25. 6% 30 th IEA Annual Workshop and symposium on EOR -Canberra

Which phenomena is more reliable? Injecting Molasses 30 th IEA Annual Workshop and symposium on EOR -Canberra ? Increasing production 4%

What types of by-products were produced? • Gases • Alcohols • Acids • Bio-surfactants • Micro-emulsion 30 th IEA Annual Workshop and symposium on EOR -Canberra

Gases and swelling • A large reduction in oil viscosity and small increase in water viscosity The Young – Laplace Equation predicts an inverse relation of pressure drop with Swelling of Oil 30 th IEA Annual Workshop and symposium on EOR -Canberra

Distribution of microbial gases Concentration (ppm) • Stimulation by carbohydrates produced substantial amounts of CO 2 and CH 4 gases • C 2+ gases desorbed from oil? CO 2 CH 4 C 2 H 6 30 th IEA Annual Workshop and symposium on EOR -Canberra C 3 H 8 C 4 H 10

Concentration (ppm) Microbial gases CO 2 CH 4 (Control) Duration of culture (days) 30 th IEA Annual Workshop and symposium on EOR -Canberra • Very high amounts of CO 2 and CH 4 gases produced • CO 2 generation continued to increase until after 9 days • CH 4 generation continued to increase until after 11 days

Alcohols production ng/m. L of water • Variable amounts of alcohols produced • Generation continued to increase until after 16 days of culture • A second cycle of moderate generation initiated after 18 days 2 2 (Control) 4 7 9 11 14 16 Duration of culture (days) 30 th IEA Annual Workshop and symposium on EOR -Canberra 18 20 22

Acids production ng/m. L of water • Variable amounts of acids produced • Consistent with gases and alcohols, generation continued to increase until after 16 days of culture • A second cycle of intense generation initiated after 18 days 2 2 (Control) 4 7 9 11 14 16 18 Duration of culture (days) 30 th IEA Annual Workshop and symposium on EOR -Canberra 20 22

Micro-emulsion experiment using cosurfactant 30 th IEA Annual Workshop and symposium on EOR -Canberra

Surfactants at the Solid-Liquid Interface Low Concentration - Surfactant Adsorption Clay Moderate Concentration - Hemimicelle Formation Clay High Concentration - Self-Assembled Surface Aggregates Clay 30 th IEA Annual Workshop and symposium on EOR -Canberra Clay

Solubility of alcohol in micelles Oil rim 30 th IEA Annual Workshop and symposium on EOR -Canberra surfactants Water droplets

Bio-surfactants w/o emulsion Micelles 30 th IEA Annual Workshop and symposium on EOR -Canberra

Oil Water droplets 30 th IEA Annual Workshop and symposium on EOR -Canberra

Oil droplets in water droplets Water droplets with oil rim 5 mm 30 th IEA Annual Workshop and symposium on EOR -Canberra

Interfacial tension and capillary pressure • Surfactant Reduce interfacial tension in small pore and reduce the capillary pressure in the system 30 th IEA Annual Workshop and symposium on EOR -Canberra R 1=2 R 2=1 Y=2 Y=1 P=(2*2)/2=2 P=(2*1)/1=2

Conclusions • Microorganisms can change threshold point of residual oil in reservoirs and to enhance oil recovery: • Core flooding using 40 ppm surfactin enable 3% EOR • Core flooding using 0. 875% molasses enable 4. 1% EOR • MEOR uses a combination of mechanisms to recover residual oils in reservoirs including • • Gas production can reduce oil viscosity Biosurfactant production can reduce IFT Solvents and biosurfactants can promote micro or nano emulsion Produced biosurfactants may change the wettability of clay rocks • MEOR could become a low cost environmental friendly EOR method in the future but more research is required 30 th IEA Annual Workshop and symposium on EOR -Canberra

Wealth from Ocean Flagship Mohammad Bahar Reservoir Engineer Phone: 08 64368954 Email: mohammad. Bahar@csiro. au Web: www. csiro. au/science/MEOR. html Thank you Contact Us Phone: 1300 363 400 or +61 3 9545 2176 Email: enquiries@csiro. au Web: www. csiro. au 30 th IEA Annual Workshop and symposium on EOR -Canberra