The Study On Economic Limit Of Tight Oil Development In Changyuan Periphery

Tight oil will become hot unconventional oil and gas exploration and development resources after shale gas successful development.Main body of Daqing oilfield has entered into the phase of high water cut and high recovery degree.As an unconventional oil resources,tight oil,one of more realistic resource,can be used as a long period in daqing changyuan peripheral has the extensive distribution.But it has difficulty on tight oil exploration and development and has the characteristics of the high cost of development.In the current international oil prices and the technical conditions,the development of tight oil has not been a clear economic limit.In this paper,we study the dynamic characteristics and economic limit of production,the research has guiding significance for economic and effective development of tight oil.This paper selects the seven parameters which influence tight oil development,established the method "seven parameters integrated classification coefficient" for evaluation tight oil blocks,and by using the seven parameters comprehensive coefficient Feci classify tight oil block;Using multiple linear regression method,the support vector machine(SVM)method,BP neural network,gray prediction method and the reservoir engineering method establish horizontal well fracturing development model to predict production volume.Compared various methods predict yield the actual production,the precision of reservoir engineering method is high;According to the experimental production dynamic analysis factors that result in the change of volume production after fracturing,the volume fracturing should adopt reasonable after flowback system and maintain reasonable bottom-hole pressure;Using engraving method fitting production decline,the volume basic accords with index of diminishing after fracturing,the early decline range is larger,the late decreasing relatively flat,the average decline rate 16%.Using the profit and loss balance principle to establish economic limit for tight oil measurement model,establish initial production,effective thickness,permeability,economic limit chart consider different oil prices and tired oil under different fracturing cost;Establish the economic limit chart optimized when the oil price of$70 a barrel,fracturing under tight oil remains unused blocks costs 25 million yuan.The paper provide the technical support and development strategys for oil field in the near future and the vision.Tight oil evaluation method,established the early yield prediction model,the law of diminishing economic chart for the development of tight oil volume horizontal well fracturing have strong practical value.