Single well has low yield in Huaqing low permeability oilfield .The wells with daily output less than 1 tons account for a larger proportion of total wells ,reaching 56 .2% in Huaqing Oilfield .Re-fracturing is an important measure to improve the production of fractured wells in Changqing ultra-low permeability reservoirs .Currently ,the re-fracturing well stimulation is not ideal by using the conventional technologies .The performances such as small yield increase ,wa-ter cut rising ,production decline suddenly ,short increasing period are appeared after re-fractu-ring .In this paper ,the hybrid slick water SRV and multi-stage temporary blocking fracturing are combined to work for old production wells in ultra-low permeability reservoirs .Considering the well pattern and injection well conditions ,the theories of volumetric fracturing and multi-stage temporary blocking are combined .After the parameters optimization in the laboratory and appli-cation of nine wells in the field ,the average single well daily output increased 2 .81 t ,the effec-tive production period for average single well is up to 252 days ,and the effect of increasing yield is significant .The successful application of this technique also provides a strong basis for the re-fracturing in ultra-low permeability reservoir .%以华庆油田为代表的超低渗透油藏定向井单井产量低，日产量小于1．0 t的低产低效井占56．2％。常规重复压裂压裂后的油井增产效果不理想，具体表现在压裂后增产幅度小、产量递减速度快、有效期短。针对长庆油田华庆区块超低渗透储层油井的重复改造，将混合水体积压裂技术应用于老井重复压裂中，形成了老井混合水体积压裂配套工艺技术，并在考虑井网和注水条件下，进行体积压裂理论与多级暂堵多缝压裂理论的结合研究。室内工艺优化结果和9口井的现场试验表明，措施后油井的平均单井日增油量2．81 t。截至目前，平均单井有效生产天数达252天，增产效果显著。该技术的成功实施运用，为超低渗透油藏重复压裂效果的提高提供了有力的依据。
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