rus
Issue #1/2017
E.Timchenko, P.Timchenko, E.Seleznyova, N.Tregub
Spectral estimation of plant tissue from oil deposit areas
Spectral estimation of plant tissue from oil deposit areas
The results of studies concerning influence of underground water accompanying oil, gas and condensate fields on vegetable biological objects are presented. The indirect method of zones identification for investigation of oil deposits is offered.
Теги: search and exploration of oil spectroscopy of plant tissues поиски и разведка нефтяных месторождений спектроскопия растительных тканей
INTRODUCTION
Now there is an increasing need to hydrocarbons resource base replenishment and detection of new and additional sources of energy commodities for oil industry. Searches and investigation of hydrocarbon fields is a difficult task and, above all is expensive. Therefore development of operational and cheap ways of oil and gas fields’ detection is an urgent task.
For rapid assessment of oil-and-gas areas biogeochemical methods are applied with minimum costs in terms of time and money. Biogeochemical searches of mineral deposits are based on chemical composition research for biological objects as a rule, of plants [1, 2].
It is known that bromine and boronions in vegetation increases over oil and gas fields. A precondition for such statement is that the geochemical factor on the basis of which zones of particular elements accumulation, first of all, of ions of bromine and boron [3] are registered.
In N. V. Dehtyaryova’s work [4] hydrogeological features of underground waters of Northwest near-Caspian zone oil-and-gas Paleozoic complexes were considered.
It was shown that distinctiveness of underground waters accompanying oil, gas and condensate fields is their mineralization. The author distinguishes such elements as fluorine, bromine, boron and others from the substances which are contained in water and plants growing in these areas.
The Raman scattering spectroscopy which allows investigatingthe structure of samples with fine precision is distinguished from a large number of methods of plants chemical composition estimation. Today the Raman scattering spectroscopy [5] for plants condition monitoring has already became one of the most important analytical and research tools. The Raman scattering spectroscopy has a number of advantages among which there are non-destructive and non-contact method not demanding a sample preparation and is a rather rapid test method (analysis time is from seconds to minutes). There are no restrictions for water content in samples (as infrared spectroscopy). So the influence of road highways proximity on the soil and plants was investigated in work by means of a method of Raman scattering spectroscopy [6]. Heavy metals were found during work in samples of soil and plants. The main changes were found at the wave number of 1065 cm–1 corresponding to concentration of zinc. The work [7] was devoted to studying of bivalent cations of metals interaction with plants DNA by means of Raman scattering. The following main wave numbers wherechanges were detected: 1239 cm–1, 1247 cm–1, 1263 cm–1 and 1243 cm–1 corresponding to fluctuations of lead, manganese, cadmium and copper ions. It is established in work of authors [8] that it is possible to carry out the essential oils’ quality evaluation test by means of the Raman scattering spectroscopy on the basis of 804 cm–1 and 811 cm–1 wave numbers difference of corresponding to molecules of thymoland carvacrol.
The research objective is an application of spectroscopy of the Raman scattering spectroscopy for detection of oil and gas fields with application of vegetable biomarkers.
MATERIALS AND METHODS
OF RESEARCHES
Researches were carried out in two steps. At first laboratory experiments were performed and on this basis their hypothesis of oil impact on Raman scattering ranges of plants was put forward. Then field researches were conducted.
The method of Raman scattering spectroscopy implemented by means of the test bench described in work [9] was used as a research method. Processing of Raman scattering ranges was carried out in Mathematica 8 software environment. The error of a method did not exceed 5.84%. The greatest statistical variability of vegetable objects optical parameters within one zone of a research is 7.93%.
The field pea (Pisumsativum) and soft wheat (Trнticumaestнvum) were chosen as objects of laboratory researches. Samples were divided into five groups, and each group was grown up in 3 pots. The first and second group of samples were control; plants were grown up in the clear soil (without hydrocarbons addition). These groups of samples were settled down nearby with samples of the third and fourth groups. The pure oil with concentration of 1 g/kg was added to the soil contained in pots with plants of the third and fourth groups. Such oil concentration is equal to maximum allowable concentration for pure oil in the soil [10]. The fifth group of the oil was grown up in 6 pots in the certain room for the purpose of exception of oil vapours influence on spectral features of plants.
The common dandelion (Tarбxacumofficinбle) was chosen as a field research object. Plants of this type are good bioindicators of environment state [11].
The following zones were chosen as the explored territories of Samara oblast:
• The first zone is the territory near the Mirnyisettlement where there is the Belozerskdeposit;
• The second zone is the territory located near the coast of Volga a part of the Country park (control zone).
The common scheme of sampling from the studied zones is provided in Fig. 1.
The oil extraction from wells is carried out now in the field near Mirnyisettlement (the area of the Belozersk and Chubovskydeposit) [12]. The samples were selected near operating and suspended wells.
The part of the Country Park located near the coast of Volga is rather removed from the large road, i. e. Novo-Sadovaya Street, and is separated from it by more than one hundred meters from the wood that reduces the penetration into the explored site of combustion gases.
Field experiments have been performed for 2 months. Research objects were selected in each area. Ranges in three various points of object were recorded from each studied leaf. We investigated more than 400 exemplars of plants and more than 1200 ranges were received during the experiments.
The monitoring of illuminating intensity, humidity and acidity of the soil was carried out concurrently by means of the Soil Survey instrument device of KC-300 model (pH determination error is 0.5, illuminating intensity error is of 9 gradations, humidity error is of 9 gradation).
RESULTS OF RESEARCHES
The reference averaged Raman scattering ranges of the studied plants samples selected from a zone of hydrocarbonic deposits and in an inspection zone where oil presence is observed are presented in Fig. 2.
The analysis of Fig. 2 and Tab. 1 shows a large number of various components which are present at plants’ samples. But not every wave number can be used as a criterion of oil influence, so 740 and 1326 cm–1 wave numbers, proportional concentration of chlorophyll and a and b can characterize influence of other external factors that is observed in a series laboratory and field researches. 830 and 1220 cm–1 wave numbers, the corresponding concentration of aromatic carbons and fluctuations of nitrogen ions in alkaloids can be served as an oil influence evaluation factor that is obvious according to a series of laboratory researches, but the changes of these wave numbers are insignificant in field researches that is bound to the fact that plants are capable to adapt to high doses of aromatic carbons and alkaloids [20, 21] in field conditions. Also the connection between the change of D-glucose concentration (915 cm–1), b-Carotinum (1522 cm–1) and oil impact on vegetable tissue [22] was not established. Presumably, these substances are changed at foreign factors influence. The interpretation of base lines of Raman scattering is given in the table.
Therefore, 605, 1 440 and 1 547 cm–1 wave numbers, proportional concentration of bromine, boron oxide and chlorophyll were taken as an index of oil influence. It is known that the change of "a" chlorophyll concentration in leaves of plants is served as an informational factor of environment influence [23] that also in turn affects the intensity of the Raman scattering. Also the content of ions of bromine and boron in vegetation increases over oil and gas deposits [11].
The dependence of Raman scattering intensity at wave numbers mentioned above for laboratory plants from time at oil effect is presented in Fig. 3. The intensity of Raman scattering on the base lines characterizing the oil influence on plants for reference samples remains constants and have an error of 7%.
The lignine is considered as one of rather constant parameters in plants [17]. Thus, the ratio between Raman scattering intensity proportional to fluctuations concentration of ions of bromine, boron and "a" chlorophyll and Raman scattering intensity proportional to lignine concentration can serve as an informative indicator defining the influence of oil deposits on plants. Therefore the following optic indices were input as the optical coefficient allowing defining the presence of oil deposits:
,
where I605 is the intensity of Raman scattering on a wave number of 605 cm–1, proportional to stretching vibrations of bromine ions in leaves of plants; I1440 is the intensity of Raman scattering on a wave number of 1440 cm-1, proportional to straining fluctuations of boron ions in leaves of plants; I1547 is the intensity of Raman scattering on a wave number of 1547 cm-1, proportional to concentration of "a" chlorophyll in leaves of plants; I1600is the intensity of Raman scattering on a wave number of 1600 cm-1, proportional to concentration of a lignine in leaves of plants.
With use of input optical coefficients two-dimensional dependences of optical coefficients of H1 from H3 and H2 from H3 for field researches were made (Fig. 4, Fig. 5). The analysis of characteristic curve showed that points of objects from control objects are grouped in the field of great values of coefficients of H1, H2 and H3. Plants from oil deposit zone are characterized by smaller values of indices of H1 and H3. So for example, N2 < 0.33 and H3 < 1 are specific for oil field zone at H1 < 0.1.
CONCLUSION
• As a result of conducted researches the features of Raman scattering ranges for plants growing in places of oil deposits were received. The main changes were recorded on 605 cm–1, 1440 cm–1 and 1547 cm–1 wave numbers corresponding to stretching vibrations of ions of bromine, boron and "a" chlorophyll in leaves of plants.
• On the basis of performed two-dimensional analysis of optical indices (H1, H2 and H3) criteria of plants division growing out of zone and in zone of the oil field are entered.
The work is performed with financial support of the Ministry of Education and Science of the Russian Federation within a design part of the government order across the fields of scientific activity No. 14.1114.2014/K (2014–2016).
Now there is an increasing need to hydrocarbons resource base replenishment and detection of new and additional sources of energy commodities for oil industry. Searches and investigation of hydrocarbon fields is a difficult task and, above all is expensive. Therefore development of operational and cheap ways of oil and gas fields’ detection is an urgent task.
For rapid assessment of oil-and-gas areas biogeochemical methods are applied with minimum costs in terms of time and money. Biogeochemical searches of mineral deposits are based on chemical composition research for biological objects as a rule, of plants [1, 2].
It is known that bromine and boronions in vegetation increases over oil and gas fields. A precondition for such statement is that the geochemical factor on the basis of which zones of particular elements accumulation, first of all, of ions of bromine and boron [3] are registered.
In N. V. Dehtyaryova’s work [4] hydrogeological features of underground waters of Northwest near-Caspian zone oil-and-gas Paleozoic complexes were considered.
It was shown that distinctiveness of underground waters accompanying oil, gas and condensate fields is their mineralization. The author distinguishes such elements as fluorine, bromine, boron and others from the substances which are contained in water and plants growing in these areas.
The Raman scattering spectroscopy which allows investigatingthe structure of samples with fine precision is distinguished from a large number of methods of plants chemical composition estimation. Today the Raman scattering spectroscopy [5] for plants condition monitoring has already became one of the most important analytical and research tools. The Raman scattering spectroscopy has a number of advantages among which there are non-destructive and non-contact method not demanding a sample preparation and is a rather rapid test method (analysis time is from seconds to minutes). There are no restrictions for water content in samples (as infrared spectroscopy). So the influence of road highways proximity on the soil and plants was investigated in work by means of a method of Raman scattering spectroscopy [6]. Heavy metals were found during work in samples of soil and plants. The main changes were found at the wave number of 1065 cm–1 corresponding to concentration of zinc. The work [7] was devoted to studying of bivalent cations of metals interaction with plants DNA by means of Raman scattering. The following main wave numbers wherechanges were detected: 1239 cm–1, 1247 cm–1, 1263 cm–1 and 1243 cm–1 corresponding to fluctuations of lead, manganese, cadmium and copper ions. It is established in work of authors [8] that it is possible to carry out the essential oils’ quality evaluation test by means of the Raman scattering spectroscopy on the basis of 804 cm–1 and 811 cm–1 wave numbers difference of corresponding to molecules of thymoland carvacrol.
The research objective is an application of spectroscopy of the Raman scattering spectroscopy for detection of oil and gas fields with application of vegetable biomarkers.
MATERIALS AND METHODS
OF RESEARCHES
Researches were carried out in two steps. At first laboratory experiments were performed and on this basis their hypothesis of oil impact on Raman scattering ranges of plants was put forward. Then field researches were conducted.
The method of Raman scattering spectroscopy implemented by means of the test bench described in work [9] was used as a research method. Processing of Raman scattering ranges was carried out in Mathematica 8 software environment. The error of a method did not exceed 5.84%. The greatest statistical variability of vegetable objects optical parameters within one zone of a research is 7.93%.
The field pea (Pisumsativum) and soft wheat (Trнticumaestнvum) were chosen as objects of laboratory researches. Samples were divided into five groups, and each group was grown up in 3 pots. The first and second group of samples were control; plants were grown up in the clear soil (without hydrocarbons addition). These groups of samples were settled down nearby with samples of the third and fourth groups. The pure oil with concentration of 1 g/kg was added to the soil contained in pots with plants of the third and fourth groups. Such oil concentration is equal to maximum allowable concentration for pure oil in the soil [10]. The fifth group of the oil was grown up in 6 pots in the certain room for the purpose of exception of oil vapours influence on spectral features of plants.
The common dandelion (Tarбxacumofficinбle) was chosen as a field research object. Plants of this type are good bioindicators of environment state [11].
The following zones were chosen as the explored territories of Samara oblast:
• The first zone is the territory near the Mirnyisettlement where there is the Belozerskdeposit;
• The second zone is the territory located near the coast of Volga a part of the Country park (control zone).
The common scheme of sampling from the studied zones is provided in Fig. 1.
The oil extraction from wells is carried out now in the field near Mirnyisettlement (the area of the Belozersk and Chubovskydeposit) [12]. The samples were selected near operating and suspended wells.
The part of the Country Park located near the coast of Volga is rather removed from the large road, i. e. Novo-Sadovaya Street, and is separated from it by more than one hundred meters from the wood that reduces the penetration into the explored site of combustion gases.
Field experiments have been performed for 2 months. Research objects were selected in each area. Ranges in three various points of object were recorded from each studied leaf. We investigated more than 400 exemplars of plants and more than 1200 ranges were received during the experiments.
The monitoring of illuminating intensity, humidity and acidity of the soil was carried out concurrently by means of the Soil Survey instrument device of KC-300 model (pH determination error is 0.5, illuminating intensity error is of 9 gradations, humidity error is of 9 gradation).
RESULTS OF RESEARCHES
The reference averaged Raman scattering ranges of the studied plants samples selected from a zone of hydrocarbonic deposits and in an inspection zone where oil presence is observed are presented in Fig. 2.
The analysis of Fig. 2 and Tab. 1 shows a large number of various components which are present at plants’ samples. But not every wave number can be used as a criterion of oil influence, so 740 and 1326 cm–1 wave numbers, proportional concentration of chlorophyll and a and b can characterize influence of other external factors that is observed in a series laboratory and field researches. 830 and 1220 cm–1 wave numbers, the corresponding concentration of aromatic carbons and fluctuations of nitrogen ions in alkaloids can be served as an oil influence evaluation factor that is obvious according to a series of laboratory researches, but the changes of these wave numbers are insignificant in field researches that is bound to the fact that plants are capable to adapt to high doses of aromatic carbons and alkaloids [20, 21] in field conditions. Also the connection between the change of D-glucose concentration (915 cm–1), b-Carotinum (1522 cm–1) and oil impact on vegetable tissue [22] was not established. Presumably, these substances are changed at foreign factors influence. The interpretation of base lines of Raman scattering is given in the table.
Therefore, 605, 1 440 and 1 547 cm–1 wave numbers, proportional concentration of bromine, boron oxide and chlorophyll were taken as an index of oil influence. It is known that the change of "a" chlorophyll concentration in leaves of plants is served as an informational factor of environment influence [23] that also in turn affects the intensity of the Raman scattering. Also the content of ions of bromine and boron in vegetation increases over oil and gas deposits [11].
The dependence of Raman scattering intensity at wave numbers mentioned above for laboratory plants from time at oil effect is presented in Fig. 3. The intensity of Raman scattering on the base lines characterizing the oil influence on plants for reference samples remains constants and have an error of 7%.
The lignine is considered as one of rather constant parameters in plants [17]. Thus, the ratio between Raman scattering intensity proportional to fluctuations concentration of ions of bromine, boron and "a" chlorophyll and Raman scattering intensity proportional to lignine concentration can serve as an informative indicator defining the influence of oil deposits on plants. Therefore the following optic indices were input as the optical coefficient allowing defining the presence of oil deposits:
,
where I605 is the intensity of Raman scattering on a wave number of 605 cm–1, proportional to stretching vibrations of bromine ions in leaves of plants; I1440 is the intensity of Raman scattering on a wave number of 1440 cm-1, proportional to straining fluctuations of boron ions in leaves of plants; I1547 is the intensity of Raman scattering on a wave number of 1547 cm-1, proportional to concentration of "a" chlorophyll in leaves of plants; I1600is the intensity of Raman scattering on a wave number of 1600 cm-1, proportional to concentration of a lignine in leaves of plants.
With use of input optical coefficients two-dimensional dependences of optical coefficients of H1 from H3 and H2 from H3 for field researches were made (Fig. 4, Fig. 5). The analysis of characteristic curve showed that points of objects from control objects are grouped in the field of great values of coefficients of H1, H2 and H3. Plants from oil deposit zone are characterized by smaller values of indices of H1 and H3. So for example, N2 < 0.33 and H3 < 1 are specific for oil field zone at H1 < 0.1.
CONCLUSION
• As a result of conducted researches the features of Raman scattering ranges for plants growing in places of oil deposits were received. The main changes were recorded on 605 cm–1, 1440 cm–1 and 1547 cm–1 wave numbers corresponding to stretching vibrations of ions of bromine, boron and "a" chlorophyll in leaves of plants.
• On the basis of performed two-dimensional analysis of optical indices (H1, H2 and H3) criteria of plants division growing out of zone and in zone of the oil field are entered.
The work is performed with financial support of the Ministry of Education and Science of the Russian Federation within a design part of the government order across the fields of scientific activity No. 14.1114.2014/K (2014–2016).
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