Drilling and completion practice on the first deep dual branch horizontal gas well in Daqing Oilfield

The Changde deep gas field of Daqing Oilfield is volcanic reservoir, most of which are tight volcanic rocks and sandy conglomerates. So it has poor drillability and poses great difficulty for drilling. In order to maximize the reservoir contact area and their producing degree, a dual branch horizontal well, Fangshen 6-shuangping 1 well, was drilled particularly in this gas field. The horizontal section length of this dual branch hole is over 1 300 m, and the sidetracking and horizontal drilling are of great difficulty. The design of wellbore configuration, wellbore trajectory and completion methods was optimized with reference to the data of offset wells and in combination of formation features. Meanwhile, the speeding-up drilling tools were used and the bottom hole assembly for upper and lower branches was optimized, so the average drilling rate of horizontal section of this well was increased remarkably compared with an offset well of same length horizontal section. The successful drilling of this well has solved the problem of single drilling technology for deep gas pools in Daqing Oilfield and provides a new method for developing deep gas wells efficiently.