Research and Application of Precision Segmented Fracturing Technology for Sidetrack Horizontal Wells

In the later stage of oilfield development, the distribution of remaining oil is highly dispersed. The remaining geological reserves of large-scale enriched and locally enriched types still reach more than 100 million tonnes. However, the effect of conventional reservoir stimulation techniques on tapping the fault-blocked, inter-well stranded, and untapped by well patterns remaining oil potential is not ideal. At the same time, the oilfield has over 1000 newly added casing-damaged wells annually, and 20% of these wells cannot be repaired, which causes the problem that local reserves cannot be developed. In view of this severe situation, Daqing Drilling Engineering Company Limited actively carried out technological innovation, and organized forces to research, develop and vigorously promote the ultra-short radius sidetrack horizontal well technology. Through a series of field tests, this technology has shown certain advantages, with an average daily oil increase of more than 3 tonnes per well. However, as the number of reservoir transformation wells increases, the problem that the ultra-short radius sidetrack horizontal well technology has an unsatisfactory transformation effect on ultra-low permeability reservoirs has been exposed. There is an urgent need for supporting stimulation measures such as fracturing. To improve the stimulation and transformation effect of sidetrack horizontal wells on ultra-low permeability reservoirs, technical tests such as general fracturing, bridge plug and fracturing, and open-hole sliding-sleeve segmented fracturing were carried out. Different transformation measures and scales have achieved good oil-increasing effects. Meanwhile an optimized design method for the fracturing technology of sidetrack wells in different reservoirs has been established, achieving the precise transformation of low-permeability or ultra-low permeability reservoirs. Field test results show that the bridge plug and fracturing technology and open-hole sliding-sleeve segmented fracturing technology for ultra-short radius sidetrack horizontal wells have achieved layer-specific and direction-specific transformation. These technologies have effectively increased the seepage area of low-permeability reservoirs, providing a powerful technical means for tapping the potential of remaining oil in Daqing Oilfield.