A NIGERIAN scientist has developed the most cost effective and efficient technology that can be used to diagnose and remediate problems associated with corrosion and souring in oil and gas industries.
Associate Professor of Petroleum Microbiology and Microbial Biotechnology, Federal University, Ndufu-Alike, Ikwo (FUNAI) Ebonyi State, Dr. Chuma Okoro, told The Guardian that the advanced technology can save up to 75 per cent of the cost used currently in managing corrosion and souring related problems in the Nigerian oil and gas industry and this translates to about N13.4 billion annually.
The study titled “Impacts of Tetrakis-hydroxymethyl Phosphonium Sulfate (THPS) Based Biocides on the Functional Group Activities of Some Oil Field Microorganisms Associated with Corrosion and Souring” was published in August 6, 2014 edition of the British Microbiology Research Journal.
The summary of the research findings was presented last week in FUNAI at the 6th edition of the Petroleum Technology Development Fund Technology (PTDF) - FUNAI Technology Knowledge Sharing Programme (TKSP).
The forum brings together science, engineering and technology researchers in oil and gas industry in Nigeria and beyond.
Okoro has also just received a United States (US) Patent for a formula he invented in 1997, ‘Sea Water Microbial Inocula,’ used for managing bioremediation in mangrove swamp.
Okoro explained: “With accurate diagnoses, remediation is very simple. The proposed remediation will avoid the use of costly biocides currently in use in the industry and adopt the uses of suicide target genes that completely shut down microbial metabolism on entering the oil formation. This process is the cheapest, very effective and most cost effective and can reduce the current cost of managing souring and corrosion related problems in Nigeria by 75 per cent.”
Oil field reservoir souring is the undesirable production of hydrogen sulphide (H2S) in oil reservoirs by sulphate reducing bacteria (SRB). This is a common problem during secondary oil recovery when sea water is injected to produce the remaining oil in the reservoir. SRB reduce sulfate in the injection water to sulfide, while oxidizing degradable organic electron donors present in the oil reservoir.
The production of sulphide by SRB in the oil and gas fields causes other problems like corrosion, reservoir plugging, deterioration of product quality and decrease in the permeability of fine pores of underground petroleum reservoirs which impedes the secondary recovery of petroleum by water injection. Souring reduces both the quality of oil and its economic value. The total cost of managing souring related problems in the Nigerian oil and gas industry is about N6.5 billion annually
Microbial induced corrosion (MIC) or bio-corrosion can be defined as an electrochemical process where the participation of microorganisms is able to initiate, facilitate or accelerate corrosion by changing the electrochemical conditions at the metal solution interface. Microorganisms are ubiquitous in oil and gas environment and may influence both the initiation and propagation of all known types of metallic corrosion. As a consequence, MIC poses a serious risk for the integrity, performance and reliability of nearly all metals used in oil and gas operations such as iron, steel, aluminum, titanium and their alloys.
Bioremediation is a waste management technique that involves the use .of organisms to remove or neutralize pollutants from a contaminated site.
Okoro further explained: “This is based mostly on sequenced based microbial biotechnology. We combine both culture dependent and culture independent methods to arrive at accurate diagnoses of problems. The culture independent methods involve the extraction and purification of Deoxy ribo-Nucleic Acid (DNA)/genetic material from samples.
“We have advanced that in the Niger Delta, a group of organisms known as methanogens are now playing major roles in bio-corrosion episodes We have also advanced that oil field microorganisms are getting more and more resistant to biocides used to control corrosion and there is need for alternative mitigation approaches.”
Okoro said the aim of the study published in British Microbiology Research Journal was to determine the biocidal efficacy of THPS based biocides currently used in oil fields to control souring and corrosion.
This, he said, is done by direct monitoring of inhibition of cell growth and inhibition of microbial functional group activities such as the ability to reduce sulfate and generate sulfide by sulphate reducing bacteria (SRB), reduce nitrate to nitrite by heterotrophic nitrate reducing bacteria (hNRB) and oxidation of sulfide and reduction of nitrate by sulfide oxidizing, nitrate reducing bacteria( so-NRB) using CSB-K medium.
The study reads: “We observed that higher doses of THPS (>400 ppm) was required to considerably inhibit the ability of SRB to reduce sulfate and generate hydrogen sulphide. It was also observed that the activities of SRB were more affected by the THPS biocides than those of hNRB and so-NRB.
“We conclude that SRB may have developed low level microbial resistance to
THPS based biocides as higher doses are required to inhibit their activities. It is therefore recommended that THPS should be used in combination with other biocides or metabolic inhibitors for it to be effective at lower concentrations.”
Okoro further explained: “Uncontrolled microbial growth in oil field systems can cause severe and costly problems such as souring of oil and gas, MIC, formation plugging and biofouling. Other negative impacts of poor microbial control in the oil and gas industry include; lost production time, poor quality crude oil and gas and occasional pipeline failures. The most common method of controlling microbial growth in oil fields has been through the application of biocides. While a wide variety of biocides are available for use in oil field systems, improved methods are required to address the problem of efficacy, microbial resistance, economic and environmental concerns.
“THPS is one of the most efficient biocides widely used in oil field operations to control oil field reservoir souring, bio-corrosion and biofouling. THPSis a water treatment biocide in 75 per cent w/w aqueous solution. It has a broad spectrum activity and it is especially effective against SRB which are particularly troublesome in enhanced oil recovery operations such as injection water treatment, top-side systems, pipeline protection and storage. THPS is widely used in the industry due to its ability to dissolve ferrous sulfide deposits, its effectiveness in both acid and alkaline environments and its low environmental toxicity.”
Okoro in yet another study published on June 16, 2014, in British Microbiology Research Journal concluded that glutaradehyde can be developed to an efficient biocide with a positive selective action and can work in synergy with beneficial microbes to eliminate the problem causing ones.
Glutaraldehyde is an organic compound. A pungent colorless oily liquid, glutaraldehyde is used to disinfect medical and dental equipment. It is also used for industrial water treatment and as a preservative.
The study is titled “Impacts of Some Non-oxidizing Biocides on the Functional Group Activities of Some Problem Causing Microorganisms in Oil Production Facilities.”
Okoro determined the impacts of some non-oxidizing biocides such as glutaradehyde, sodium azide, isothiazolone on the functional group activities of some oil field microorganisms
He obtained samples of non-oxidizing biocides were from Microcheck and the
inhibition of some functional group activities in produced and injection water samples were determined using CSB-K medium.
The results of the study show that glutaradehyde and sodium azide exhibited relatively high-level inhibition while isothiazolones exhibited low level inhibition. Glutaradehyde further demonstrated a positive selective inhibitory activity. While SRB activities were inhibited by over 78 per cent, that of hNRB and so-NRB were affected by less than 38 per cent.
Okoro and his team of researchers in another 2014 study published in Journal of Industrial Microbiology and Biotechnology compared microbial communities involved in souring and corrosion in offshore and onshore oil production facilities in Nigeria.
The other researchers include: S. Smith of Shell Nigeria Exploration and Production company (SnEPcO), Lagos; l. Chiejina Shell Petroleum Development company (SPDc) of Nigeria, Port Harcourt, Rivers State; and R. Lumactud Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, On M1c 1a4, Canada; H. S. Park and J. Voordouw of the Department of Biological Sciences, University of Calgary, and B. P. Lomans of Shell Global Solutions International Netherlands.
Vice Chancellor FUNAI, Prof. Oye Ibidapo-Obe, his presentation titled ‘National University Technology Research Development Issue: Our Fears and Hope’ said: “We are particularly focused at this on the Establishment of Faculty of Engineering and Technology in FUNAI and training of our academic staff. We wish to use this golden opportunity to remind the New Executive Secretary of PTDF that the former ES – Dr. Oluwole Oluleye had given approval to our earlier request for the up-grading of Department of Chemical and Petroleum Engineering in FUNAI during the next up-grading exercise come 2015. The Executive Secretary, we still wish to appeal that you use your good offices for a special dispensation to you to come to the aid of FUNAI in ensuring that the above stated request of up-grading project is given urgent attention by the Fund.
“The Plenary Lecture for this year, ‘Sequence Management Approach in Research Development in Nigeria: Implication for PTDF/Funded Research’ is quite topical. We hope that the Lecture will cover not only Research and Development but also the Commercialization of the Research Findings for National Development.”
Ibidapo-Obe said contemporary events in this country have revealed that research is not adequately funded hence PTDF’s intervention in funding standard research topics in areas of oil and gas as well as in renewable energy is laudable.
The FUNAI V.C. further explained: “To say the least, PTDF has done marvelously well in the funding of research and training of Nigerians Overseas to carry out research at Master’s and Doctoral levels. Also, the Fund in its bid to promote research instituted PTDF Chairs in various Universities in Nigeria, and the topics to be presented today and tomorrow are products of such sponsorship/promotion. Interestingly enough, FUNAI is one of such Institutions that are enjoying the PTDF Annual Oil and Gas Research Grant for 2012 – 2014. While we look forward to more collaboration with the Fund in Research and Teaching, we hereby kindly request that this project be quickly facilitated and enough fund be released to the Research Team and on time to enable them complete the second phase of the research as recommended by the Peer Reviewing Committee in September,2014.”
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