The Methods To Analysis Of Minimum Ground Stress Based On Fracture Construction Curves

As an important method for oil and gas reservoir reconstruction,hydraulic fracturing whose development in theory and technology is very rapid is effective for oil or gas well stimulation and has attracted more and more attention by the reservoir reconstruction experts.The minimum stress is one of important parameters in the hydraulic fracturing design.The longitudinal distribution of the minimum in-situ stress plays a significant role in the crack initiation and propagation.The difference of minimum in-situ stress between the adjacent layers has an effect on the fracture height,length,fluid efficiency,net pressure and construction displacement However,at present,the application of fracture interpretation technique is narrow and the error from the traditional method is larger.Therefore,in order to optimize fracturing design,it is necessary to determine the minimum in-situ stress exactly.Based on the use of traditional fracturing methods to calculate the minimum stress theories and on the previous technologies,analysis and methods from a number of scholars at home and abroad,development and perfection of the fracturing construction method to calculate the minimum stress theory further is needed.With the improvement of the common Nolte G function,this article proposes a new Nolte G function fitting method,which improves the accuracy of the closing pressure.The curve is divided into two sections,which are fitted in proper form and closed point is determined by them.In addition,the step up displacement methods to calculating extension pressure are studied,and it discoveries a method to improve the accuracy of the extended pressure.Then compared with the results of traditional models,they are closed.Finally,on the basis of theoretical research,it makes use of C# and WPF to develop a set of minimum stress analysis software mainly for Windows operation environment.And using data from a well in Tarim Region,it takes some calculation examples by software.The results willbe compared with other methods and errors are very close,which has a good reliability and applicability of software.