Research and application of shielding temporary sealing and refracturing techniques in BZ block of Junggar basin

The shielding temporary sealing and refracturing technique is initially a kind of duplicated treatment on the development of low-permeability reservoir in Changqing oilfieid.As enhanced production has been achieved,the technique has been adopted in BZ block of Junggar basin in 2004.Through optimization on geological features,de- velopment features,technique flexibility and construction parameters,the technique is improved to be more suitable for the area.Up to now,the new technique has been suc- cessfully applied on 37 wells in BZ block of Junggar basin and the success rate can be up to 95% and the effective rate is 85%,which increases average daily oil production of 4.1 t.The valid period of single well is 240 days aver agely,and 570 days for part of wells.It has been proved that the technique has great application potential and can be broadly adopted in Junggar basin.