THE ECOLOGICAL CONDITION OF VAH RIVER BASIN WATERCOURSES

Grebeniuk G.N.

d.g.s., professor of Nizhnevartovsk State Humanitarian University,

mob.ph. 89129337572, Е-mail:рligun48@mail.ru

Kozelkova Е.N.

c.g.s., senior lecturer of Nizhnevartovsk State Humanitarian University

mob.ph. 89195334955, Е-mail: kozelkova1@rambler.ru

Water quality, pollution, oilfield, the oil and gas complex.

A superficial water quality characterizes ecological condition both water objects itself, and basin territory as a whole. Taking into account specific character of landscape on Vah river basin territory (the right branch of the Ob), oil pollutions are mainly harmful in open low bogs and lakes. Development of the oil and gas complex caused numerous ecological problems.

The term «water quality» means a description of water composition and properties, which determine its aptitude for concrete forms of water consumption and water use (1). You should understand that natural water pollution is alteration of natural content one substance or another, creating deterioration of water quality for a consumer and water use; also for natural ecosystem existence as a result human being economic activities. And at the same time, low water quality is not excluded, when natural factors effect. Generally economic activities make essentially worse unfavorable natural background (2).

Mechanism of forming Vah river basin waters quality (Middle Priobye) (Cреднее Приобье), is not studied enough. However, late years a large complex of studying superficial waters quality on this territory works is being carried out; but, unfortunately, there is no constant data correlation over its lack of uniformity and absence of common conception as respects to space-time referencing. Meanwhile, by now, at Hydrometeorological service network extensive information about river waters quality and conditions is collected, which is required theoretical summarizing; and may be primary for follow-ups, including eventual ones.

The result of our research carried, is main stress on natural complexes in the territory connects with oilfield exploitation. A half of area’s landscape territory (55 %) is occupied by licensed field of oil producing enterprises.

Within basin a large number of different sites both technological and social orientation are built. There is a heavy network of roads and pipelines, which connects together numerous well bushes at the territory.

Disturbance area around every well bush site are equal to bush active area in flood land conditions, and often exceed the last one in a water parting. According experts’ evaluation average square of the bush site in flood land conditions is 1.9 – 2.1 hа; disturbance area around it has the same square столько же (or more). Spill ails, underflooding and rubbish are typical.

It is necessary to note, that square occupied by bush site together with different type of disturbance areas included, is up to 1% from total area of every oilfield. As a whole, flora extinction in damage floods places from oil sumps is associated with negative drilling waste products influence on agrophysical soil properties (increasing of density and water-retentive ability, loss of structure and water permeability).

Taking into account a specific character of landscape at the territory, oil pollution are mainly harmful in open low bogs and lakes. At this places oil pollution is brought in water objects and becomes dangerous to existence of biogeocenosis, which are situated far off spill ail areas. Oil pollution, appeared in holes with an active runoff, because of flowing wetting, is carried out beyond a border of terrace, and contaminates the flood land and the Vah. The oil and gas complex has direct and mediate influence on chemical indices of water objects. Mediate is the transformation of natural constituents’ properties (surface layer, soil), which are river run-off quality forming factors. Direct influence on natural waters quality is effluent of different nature and composition sewage water (SW) to rivers, lakes and to collecting area; increasing of river water turbidity while erosion of valley edge rock, broke by transportation links laying.

Within Nizhnevartovsk region oily zones are most widespread, which formed attached to accident exploitation of inside commercial tail areas, middle commercial и main pipelines, borehole accessories; attached to breaking of petroleum production objects repair rules, holding fuels and lubricants, etc. All this creates background quality, more or less close to local run-off waters «natural» quality, which is typical for this region.

The oil and gas complex development caused numerous ecological problems. Putting into operation every oil field is connected with industrial development large areas, where deforestation is, sand quarrying pits are developed, foundation for buildings and well bushes are made, operational, blowing, water intake wells are drilled, hundreds kilometers of engineering transportation links and highways are built, diversified service economy is created. All this gives rise to breaking hydrological, hydrogeological and frozen conditions, alteration of relief, soil-vegetable covering, territories microclimate, animal and plant association species composition both within new construction building and in zone of its influence. There is not only point ecosystem destruction, but and wide areal destruction are forwarded by developed hydraulic network, where bogs are interlinks (its fall to the share of 40-80 % from square in different regions of Eastern Siberia). Bogs become pollution accumulators and distributors. Pipelines, built on surface bogs and crossing have negative influence on the superficial waters dynamics. In Middle Priobye (Среднем Приобье) hundreds of junctions through 192 are built while equipping oilfields. More than 100 watercourses are only constructed at Agan river (544 km), right branch of the Ob. And at the same time there is great destruction of flood lands and river-beds.

Oil production intensification by means of increase formational pressure by flooding, (formation watering is 60-80 %) resulted disastrous of complications, connected with carryover of admixtures and highly carbonated waters; and as a result there is progressive growth of pipeline accident series. (Nowadays in 11 oilproducing associations only 60 thousands km of inside commercial and middle commercial pipelines are operated.) If at the beginning of 80-es about 200-300 accidents was by inspecting bodies, that from 1989-1992 years to 9 oilproducing associations formal registered 2500-3000 accidents per year, and from 1993-2007 years - 4000-4500 accidents per year according to formal data.

Main causes of emergency situations were pipeline corrosion (70-90%), construction defect (10-15%), mechanical damages (4-12%). Pipe line corrosion rate evidently surpasses replacement corrosion- risk ability. As a result a large number of interstitial bottom water and crude oil fall into relief. According to inspecting bodies information in 1989 loss of oil were 70 thousands t, in 1990 - 82 thousands t, in 2003-2007 - up to 102 thousands t. At the same time one ought to note that damage assessment is determined at best in 1 % of events: in 1989 10 lawsuits were brought to 3034 accidents, in 1990. – to 2810 accidents - 23 lawsuits, in 1991 – to 2454 accidents -30 lawsuits, and during 2002 to 2007 180 lawsuits were brought. According to our evaluation about 2 % oil of production is brought to environment at Nizhnevartovsk region territory; and oil production is approximately 5100 million t.

Pipeline, wells, compressed air plant accidents are main sources of carrying oil hydrocarbons (OH) (НУВ) to water bodies. According to experts’ evaluation, a share is 53 % from total volume of oil carried to water bodies. According to other sources, shares of slurry barns, sewage water, plumes, and fleet are respectively 35; 9; 2; 0.2 %. It is necessary to note, that this evaluation is approximate, because there is no quantitative registration of all accidents which take place and quantity of oil spilled; registration drilling sludge accumulated in water collection area and waste muds, containing oil; there is no assessment of dripping oil output when casing-head gas burns. An important source - unorganized runoff from water collection area - is not considered. At the same time 8-12 bln.sq.m of casing-head gas burns in plumes every year in the region; 1563 units of slurry barns are not eliminated in Nizhnevartovsk region only.

But not only oil is the Vah basin pollutant, though nowadays a share of it is about 80 % from pollution. Besides oil different reactant applied in downstream (more than 100 names) are brought to water bodies. Main part of oil runoffs is interstitial bottom water, which is characterized by high mineralization (up to 230 g/l), presence of suspensions (up to 1.7 g/l), bromine, iodine, iron и and others. In run-offs from oil preparation is contained up to 10 g/l of OH, up to 8 g/l of demulsifying agents, up to 1.5 g/l of sulphates, up to 45 mg/l of ferrous oxide, a large number of surfactants etc. And though these waters are pumped to formation, frequent vortexes impulses are reason of its falling into water bodies and water collection area. Sewage water mineral components, falling in a large number into water bodies, have essentially changed small river hydrochemical conditions. So, practically, all small rivers running through Samotlor oilfield are salting. Content of chlorides exceeds background value at 2.5-180 times, total mineralization - at 2-26 times. Ion ratio has changed. Hydrocarbonate - calcium water turns into chloride - sodium - magnesium one.

Thus, ecological condition of Vah river watercourses has progressive worsening of natural water quality, as a result of growing number of accidents, output from oil production territory and fault of crude sewage to water bodies.

Literature:

1. Гребенюк Г.Н. Козелкова Е.Н. Гусев И.С. Влияние нефтедобывающей промышленности на качество воды реки Обь (в районе г. Нижневартовска). / Г.Н. Гребенюк, Е.Н. Козелкова, И.С. Гусев // Города России: проблемы строительства. Инженерного обеспечения, благоустройства и экологии: сборник статей X Международной научно-практической конференции.- Пенза: ПГСХА, 2008-С.73-76.

2. Емельянова В.П. Оценка качества поверхностных вод суши по гидрохимическим показателям / В.П. Емельянова, Г.Н. Данилова, Т.Х. Колесникова [Монография] // Гидрохимические материалы, 1983 г. С. 56-58