Effectiveness of In-Situ Microbial Enhanced Oil Recovery in a Post-Polymer Flooded Reservoir

This study investigated the effectiveness of In-situ microbial enhanced oil recovery (IMEOR) in a post-polymer flooded oil reservoir located in SaNan oilfield, Northeast China. Two rounds of injection of nutrient medium were intermittently injected into the producing block and then monitored. The main results showed that the dominant bacteria of 4 production wells, Thauera of Beta-proteobacteria, Pseudomonas and Acinetobacter of Gamma-proteobacteria were directional activation, which showed a consistent enhancement. The abundance of Methanosaeta and Methanolinea increased, and showed a regular alternation with an increase of oil production. It contributed to production of bio-gas, leading to increasing of the injection pressure from 11.3 MPa to 13.9 MPa before the experiment which increased by more than 2.0 MPa. The contents of CO2 and CH4 varied alternately, and the variation was consistent with the order of injection of each activator. H2 was detected in the reservoir associated with the gas in the observation area. A large amount of enriched bio-gas was dissolved into and mixed with crude oil, which brought increasing of the proportion of light components in the whole hydrocarbon of the recovered oil. The other effect was activated microbial metabolites productions formed bio-plugs, which benefits for improving of the absorption profile and the production profile. A total of 6,243 t of incremental oil production was achieved, and an oil recovery rate increased by 3.93% (OOIP) to the end of 2015. Our trial suggested that IMEOR can be implemented for effective enhancement of further oil recovery from polymer flooded oil reservoirs.

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VARIATION OF CARBON SOURCES IN PRODUCTING RHAMNOLIPID BY Pseudomonas aeruginosa FOR MICROBIAL ENHANCED OIL RECOVER�S APPLICATION (VARIASI SUMBER KARBON PADA PRODUKSI RHAMNOLIPID OLEH Pseudomonas aeruginosa DALAM APLIKASI MICROBIAL ENHANCED OIL RECOVERY (MEOR))

Scientific Contributions Oil and Gas ◽

10.29017/scog.40.1.36 ◽

2018 ◽

Vol 40 (1) ◽

pp. 33-40

Author(s):

Nafian Awaludin ◽

Cut Nanda Sari

Keyword(s):

Pseudomonas Aeruginosa ◽

Enhanced Oil Recovery ◽

Oil Recovery ◽

Carbon Sources ◽

Oil Production ◽

Waste Cooking Oil ◽

Microbial Enhanced Oil Recovery ◽

Interface Tension ◽

Cooking Oil ◽

Production Wells

The decrease in oil production is caused by the ageing of oil production wells. The enhanced oil recovery (EOR) technology is proven to increase oil reserves and production in mature oil fields. One EOR technology that has proven to be efficient in increasing oil production is microbial EOR by using biosurfactant. The most effective biosurfactant is rhamnolipid produced by Pseudomonas aeruginosa, the bacteria of which can lower the interfacial tension between the petroleum and water. In biosurfactants production thanks to these bacteria, the substrate as the source of carbon in the fermentation process is needed. The sources of carbon used in this study are glucose, glycerol, molasses, banana peels, and waste from Pseudomonas aeruginosa by using Busnell Hass medium as a liquid medium of bacterial growth. Biosurfactants production results are; 74mg/L from glucose; 63mg/L from banana peels; 66mg / L from glycerol; 85mg/L from waste cooking oil; and 64mg/L of molasses with the following decreasing surface tension: 33.55 mN/m from glucose; 32.51 mN/m from banana peels; 27.55 mN/m from glycerol; 22.46 mN/m from waste cooking oil; and 31.49 mN/m from molasses. In addition, the decrease of interface tension of glucose; banana peels; glycerol; waste cooking oil; and molasses are as follows : 15.2 mN/m; 13.78 mN/m; 8:15 mN/m; 0.14 mN/m; and 11.2 mN/m respectively.Menurunnya produksi minyak bumi disebabkan karena sumur produksi yang sudah tua. Teknologi enhanced oil recovery (EOR) terbukti mampu meningkatkan cadangan dan produksi lapangan minyak mature. Salah satu teknologi EOR yang dikenal efi sien dalam meningkatkan perolehan minyak adalah microbial enhanced oil recovery menggunakan biosurfaktan. Biosurfaktan yang paling efektif adalah rhamnolipid yang dihasilkan oleh bakteri Pseudomonas aeruginosa yang dapat menurunkan tegangan antarmuka antara minyak bumi dengan air. Dalam produksi biosurfaktan oleh bakteri ini, diperlukan substrat sebagai sumber karbon dalam proses fermentasi. Sumber karbon yang digunakan pada penelitian ini adalah glukosa, gliserol, molase, kulit pisang, dan minyak jelantah. Penelitian ini bertujuan untuk mengetahui sumber karbon yang paling optimum dalam menghasilkan biosurfaktan dari Pseudomonas aeruginosa dengan menggunakan busnell hass medium sebagai media cair pertumbuhan bakteri. Produksi biosurfaktan yang dihasilkan adalah 74mg/L dari glukosa; 63mg/L dari kulit pisang; 66mg/L dari gliserol; 85mg/L dari minyak jelantah; dan 64mg/L dari molase dengan penurunan tegangan permukaan berturutturut: 33,55 mN/m dari glukosa; 32,51 mN/m dari kulit pisang; 27,55 mN/m dari gliserol; 22,46 mN/m dari minyak jelantah; dan 31,49 mN/m serta memiliki penurunan tegangan antarmuka dari glukosa; kulit pisang; glisero; minyak jelantah; dan molase berturut-turut adalah 15,2 mN/m; 13,78 mN/m; 8,15 mN/m; 0,14 mN/m; dan 11,2 mN/m.

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Discerning In-Situ Performance of an Enhanced-Oil-Recovery Agent in the Midst of Geological Uncertainty: II. Fluvial-Deposit Reservoir

SPE Journal ◽

10.2118/174613-pa ◽

2019 ◽

Vol 24 (03) ◽

pp. 1076-1091

Author(s):

S. A. Fatemi ◽

J.-D.. -D. Jansen ◽

W. R. Rossen

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Injection Pressure ◽

Geological Uncertainty ◽

Polymer Injection ◽

Fluvial Deposit ◽

Water Breakthrough ◽

Production Wells ◽

Reservoir Description

Summary An enhanced-oil-recovery (EOR) pilot test has multiple goals, among them to be profitable (if possible), demonstrate oil recovery, verify the properties of the EOR agent in situ, and provide the information needed for scaleup to an economical process. Given the complexity of EOR processes and the inherent uncertainty in the reservoir description, it is a challenge to discern the properties of the EOR agent in situ in the midst of geological uncertainty. We propose a numerical case study to illustrate this challenge: a polymer EOR process designed for a 3D fluvial-deposit water/oil reservoir. The polymer is designed to have a viscosity of 20 cp in situ. We start with 100 realizations of the 3D reservoir to reflect the range of possible geological structures honoring the statistics of the initial geological uncertainties. For a population of reservoirs representing reduced geological uncertainty after 5 years of waterflooding, we select three groups of 10 realizations out of the initial 100, with similar water-breakthrough dates at the four production wells. We then simulate 5 years of polymer injection. We allow that the polymer process might fail in situ and viscosity could be 30% of that intended. We test whether the signals of this difference at injection and production wells would be statistically significant in the midst of geological uncertainty. Specifically, we compare the deviation caused by loss of polymer viscosity with the scatter caused by the geological uncertainty using a 95% confidence interval. Among the signals considered, polymer-breakthrough time, minimum oil cut, and rate of rise in injection pressure with polymer injection provide the most-reliable indications of whether a polymer viscosity was maintained in situ.

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