Abstract:

The characteristic of directional well fracturing in western Sichuan is fracturing pressure and the friction near wellbore is very high,fracture feature is complex,directional wells operation pressure is higher than straight wells′,and its fracturing effectiviness is bad versus straight wells′.Analysis on the reason of the characteristic of directional well fracturing and the result are as follows,obviously near wellbore influence,fracture diversion and many fractures coming into being are the main reasons that make fracturing operation difficulty and the effectiviness worse than vertical well′.According to research on hydraulic fracturing technology of directional wells，the measurements are optimized perforation,proppant slug in prepad fluid,lineal gravel input,altering delivery rate,variable viscosity fracturing fluid and increasing the amount of prepad fluid and proppant and so on.There are sixteen directional wells field application in Majing and Xindu gas fields in western Sichuan.The successfull proportion of wells that are implemented is 100%,The proportion of industry gas wells attained to 94%,The multiple proportion of gas AOF after directional and straight well fracturing in 2005 is 2.01,however,the multiple proportion drops to 1.39 in 2006,The gap between directinal and straight productivity in the same region of wells reduce obviously.The research in this paper offers available approaches for developing directional wells,the effectiviness of field application is obvious.The research is of important popularization and practical application value.

Key words: directional wells, hydraulic fracturing, technique, research, field application