Horizontal well drilling and hydraulic fracturing of this large-scale multi-stage two technological breakthroughs ,hydraulic fracturing has made mining impermeable rocks hidden in hydrocarbons as possible. In 2004, the U.S. level of less than 10% of natural gas wells , now it is 61%.
Globally, although many countries have set up demonstration projects , but most still come from shale gas production in North America . After experiencing a period of rapid growth, since the beginning of 2012 , production has remained at a relatively stable level. Shale gas production has grown from 2000 accounted for 2% of U.S. natural gas production , gas production increased to 2012 nearly 40 percent ; period of U.S. natural gas production grew by 25%. The oversupply led to a sharp drop in U.S. natural gas prices . Currently, the prices have been some slight rebound , but for many no liquid hydrocarbon production capacity of shale gas field , the result of low natural gas prices due to their lack of profitability.
Large-scale shale gas production first began in the Barnett Shale area 10 years ago and quickly spread to other regions.fracturing proppant Five shale gas production 80% of U.S. shale gas production in descending order by : Louisiana Haynesville, East Texas Barnett, across West Virginia , Pennsylvania and New York State Marcellus, Arkansas in Fayetteville, and Oklahoma Woodford.
Currently, there is a specific pattern have occurred . A shale gas field was discovered, one leasing boom ensues. In the United States , given the high oil and gas exploration and development risks and returns , the parties to balance the distribution of benefits and reduce the risks and reduce uncertainty , has long formed the oil and gas lease system . Private , federal or state government landowners , mineral interests in oil and gas resources will be granted to oil and gas developers, and developers have capital and technology , access to such mineral interest in the exploration, development and production. Then it is 3 to 5 years of natural gas boom, because if a given location is no longer producing gas lease sale will be terminated. Shale gas -rich region known as dessert, was first identified and drilling , and then determine its edge region . The average gas quality ( determined by the initial capacity ) to initially rise and then begin to decline.
Since 2010 , the five largest shale gas field in the United States there are four gas fields , the average yield has been declining. In the Haynesville, 2012 , the average yield of almost a third more than 2010 youth . Marcellus is an exception : in this young , huge shale fields , and still continue to be found and mined , its supply is still maintained growth.
A gas well production will decline rapidly within a few years . U.S.
shale gas in five wells in the first three years after production fell by 80% to 95%. Represented by fitting hyperbolic production decline trend of industry practice , and infer the life of wells can reach 40 years or more, a little too optimistic. Available historical production data up to only a few years , therefore , not enough to be able to have such wells confirmed a long life . As production declines faster than the typical conclusion of these models , this method often overestimated ultimate recovery wells and economic indicators . U.S. Geological Survey assessment of recoverable amount , and sometimes even less than the industry touted recoverable amount of the half.
In order to maintain the supply of new wells must be drilled . In the Haynesville gas well, almost a year need to create 800 wells - almost 2012 the number of gas wells in service 1/3-- to maintain production levels in 2012 . Each well costs about $ 900 million investment , in order to maintain production was essentially flat drilling takes $ 7 billion annually , if coupled with leasing , infrastructure and interest , including the total cost is even higher.
From the United States point of view, this is equivalent to the new 7200 wells per year , spend at least $ 42 billion , they can only offset the decline in production . In order to maintain production to support the lower shale gas prices, drilling ventures can not be completely recovered from sales . In 2012, the U.S. shale gas output value of only 33 billion ( although some wells also produce a considerable amount of liquid hydrocarbon , thereby enhancing the economy ) . For non- production of liquid hydrocarbons shale gas field , even if just to keep ends meet , but also need to increase gas prices .
In order to maintain production of shale gas , the industrial sector needs a lot of money . Over time , the best and the dessert is drilled shale field is completed, maintain the supply costs will rise .Frac sand Many existing shale gas production is not economical , even if only to maintain production , we need higher gas prices , not to mention increase production up .
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