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Optimization of intermittent gas lift wells
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Optimization of intermittent gas lift wells
At the low productivity wells and low and high productivity wells with low reservoir
pressure continuous gas lift wells fail to work. Normally, when the minimum liquid rate is
reached the production should be switched to intermittent gas lift. In this study, the main
idea is to determine the high pressure cutoffs, optimize flow and maximize recovery with
possible minimum gas volume. Here high instantaneous gas rates are replaced by the
periods of no gas injection repeatedly. The predetermined periods of gas injection are
managed by time cycle controller. Preference is completely automatic time cycle controls
in order to accuracy for adjusting the duration and frequency of the injection gas cycle.
There is almost no chance for clock stoppage as clock driven pilots.
At continuous gas lift for optimizing the flow the Q=Q(V) curves are utilized which had
been proposed by Az. OGRDI (Oil and Gas Research Design Institute). However, due to low
flow rate and unstable production, this method is not eligible for intermittent gas lift. The
method to optimize flow and get maximum recovery the method below is proposed.
Initially the time controller is adjusted for 3 or 4 different time cycle and duration of
gas injection. The readings of gas and produced fluid flow rate are taken from gas and
liquid flow meters. These procedures are repeated for 5 times. And the results are written
in a table. From this table the condition is accepted as the optimal which gas injection
volume is lowest and recovery is high. And we can easily identify operating conditions
that could be modified in order to optimize gas consumption and maximize liquid
production.
© Turkan Abasova (Master’s degree student with Petroleum Engineering major/ Azerbaijan
State Oil and Industry University)
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Environmental impact of petroleum industry
One of the global problems of our days is pollution .How to save our ecology? What to do for less
evaporation of toxic matters? Year by year scientists try to investigate new apparatus ,new filters for
cleanse oil waste and toxic maters. Now I will try to explain you our main oil industry pollution
problems ,and also I will try to explain you the “way out”))
The environmental impact of petroleum is often negative because it is toxic to almost all forms of life
and its extraction fuels climate change. Petroleum, commonly referred to as oil, is closely linked to
virtually all aspects of present society, especially for transportation and heating for both homes and for
commercial and industrial activities.
TOXCITY
Crude oil is a mixture of many different kinds of organic compounds, many of which are highly toxic and
cancer causing (carcinogenic). Oil is "acutely lethal" to fish - that is, it kills fish quickly, at a
concentration of 4000 parts per million (0.4%). Crude oil and petroleum distillates cause birth defects.
Benzene is present in both crude oil and gasoline and is known to cause leukaemia in humans. The compound is also known to lower the
white blood cell count in humans, which would leave people exposed to it more susceptible to infections."Studies have linked benzene
exposure in the parts per billion (ppb) range to terminal leukemia, Hodgkins lymphoma, and other blood and immune system diseases within
5-15 years of exposure."
Petroleum distillates can create a sheen on the surface of water as a thin layer creating an optical phenomena called interphase.
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ACID RAINS
Now lets speak a little more about acid rains. I think many of us have seen or heard about red rains in Riga, or yellow rains at Chernobyl. All of
this rains are toxic and take their sources from chemical fabric gases. High temperatures created by the combustion of petroleum cause
nitrogen gas in the surrounding air to oxidize, creating nitrous oxides. Nitrous oxides, along with sulfur dioxide from the sulfur in the oil,
combine with water in the atmosphere to create acid rain. Acid rain causes many problems such as dead trees and acidified lakes with dead
fish. Coral reefs in the world's oceans are killed by acidic water caused by acid rain. Acid rain leads to increased corrosion of machinery and
structures (large amounts of capital), and to the slow destruction of archaeological structures like the marble ruins in Rome and Greece.
WASTE OIL
Waste oil is used oil containing not only breakdown products but also impurities from use. Some examples of waste oil are used oils such as
hydraulic oil, transmission oil, brake fluids, motor oil, crankcase oil, gear box oil and synthetic oil. Many of the same problems associated with
natural petroleum exist with waste oil. When waste oil from vehicles drips out engines over streets and roads, the oil travels into the water
table bringing with it such toxins as benzene. This poisons both soil and drinking water. Runoff from storms carries waste oil into rivers and
oceans, poisoning them as well.
VOC-Volatile organic compounds (VOCs) are gases or vapors emitted by various solids and liquids, many of which have short- and long-term
adverse effects on human health and the environment. VOCs from petroleum are toxic and foul the air, and some like benzene are extremely
toxic, carcinogenic and cause DNA damage. Benzene often makes up about 1% of crude oil and gasoline. Benzene is present in automobile
exhaust. More important for vapors from spills of diesel and crude oil are aliphatic, volatile compounds. Although "less toxic" than
compounds like benzene, their overwhelming abundance can still cause health concerns even when benzene levels in the air are relatively
low. The compounds are sometimes collectively measured as "Total Petroleum Hydrocarbons" or "TPH." Petroleum hydrocarbons such as
gasoline, diesel, or jet fuel intruding into indoor spaces from underground storage tanks or brownfields threaten safety (e.g., explosive
potential) and causes adverse health effects from inhalation.
© Toghrul Qurbanov – Weatherford Volunteer Student
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