OIL AND GAS INDUSTRY AMERICAN TRADITIONAL MARKET CONDITIONS
The number of drilled oil and gas wells in the world is huge. Most of the wells are in the United States. It was established that in vertical wells the hydrocarbon extraction is not more than 25-40 %, and for horizontal less than 10 %. Extraction of oil, mainly confined to the good collectors. More than 70-80 % of the cemented reservoirs contain basic unrecoverable hydrocarbons.
There are millions of wells. A large part of them liquidated. Among the millions of working oil wells are about 400 thousand low-productive (from zero to 3-5 barrels per day), and even closed (abandoned) wells.
At the same time, during all period of exploitation of the wells in most cases was used no more than 25-35 % of the available stocks. Geological estimates show that the residual oil reserves are still around 200 billion barrels of oil. The age of most low-production wells 60 - 80 or even 100 years.
As shows analysis of oil production, registered in the state and national databases, during the operation well flow rate is reduced to 10-12 barrels per day and in many cases to zero.
There are a number of reasons for the fall production rate: pressure drop in the reservoir, flooding, screening, colmatation (mudding). The actual depletion of productive layer is less common.
Studies have shown, that almost all the main cause is used incorrect methods of primary opening the productive formation, among which stand out bullet perforations in the old wells. Since the late sixties bullet perforations replaced cumulative perforation. Cumulative perforation leads to destruction of productive layer in the wellbore zone, and the subsequent attempts to re-perforation do not give some positive results.