Abstract:

In order to accurately determine effective hydraulic fracture length and its influencing factors of gas well,to improve the pertinence of hydraulic fracturing in Xujiahe Reservoir, West Sichuan, the relationship between effective length obtained from the gas wells and propped length obtained from net pressure fitting is determined.The degree of the parameters influence on effective length is analysed by grey correlation analysis theory, and its implication to fracturing design is also analysed.Calculation results showed that there is a noticeable correlativity between  effective length and propped length (Le=0.0584 Lp13593), and effective length is shorter obviously than propped length; construction parameters (especially fracturing fluid volume) is the primary determinant of effective length in Xujiahe Reservoir,and the stress difference between barrier and interbed is the key objective factor.This research provides a reference for postfracturing evaluation and improvement of hydraulic fracturing design level.

Key words: effective fracture length, tight reservoir, propped fracture length, grey relationship, influencing factor, postfracturing evaluation