基于导流能力评价实验的复合酸化压裂技术

Composite Acid Fracturing Technology Based on Flow Conductivity Evaluation Experiments

酸化压裂是碳酸盐岩油气藏增产的主要措施和手段,即使采用较大规模施工,酸蚀缝长一般不超过120 m,而水力压裂技术能够实现大规模造长缝的目的。为此,开展水力压裂与酸携砂压裂相结合的复合酸化压裂技术研究及现场实验,以探索碳酸盐岩增产措施的新工艺技术。实验采用塔里木盆地奥陶系碳酸盐岩岩心,模拟高温高压地层条件,通过测试水力加砂压裂裂缝、酸化压裂酸蚀缝、酸携砂压裂裂缝、水力压裂与酸携砂复合酸压裂缝的短期导流能力,探索评价了碳酸盐岩地层增产改造的新工艺技术,实验结果表明了碳酸盐岩地层实施复合酸化压裂可以实现较好的导流能力。基于导流能力实验评价结果,优化设计了4口井的复合酸化压裂方案并进行现场施工,增产效果良好,为碳酸盐岩地层实施复合酸化压裂提供了有力的理论支持。

Acid fracturing is one of the most commonly adopted techniques and methods to improve the production of carbonate re-servoir.However its resulting acid etched fractures are generally not exceeding 120 meters even in large scale filed application.Hydraulic fracturing,on the contrary,can reach the goal to generate long fractures.To explore new developing technology for carbonate reservoir,both experiments and field study on utilization of composite acid fracturing,a combination of hydraulic fracturing and proppant-carrying acid fracturing,were conducted.Ordovician carbonate cores drilled from Tarim Basin was used,short-term flow conductivity of fractures generated by proppant-carrying hydraulic fracturing,acid-etched fracturing,proppant-carrying acid fracturing and the composite acid fracturing combined hydraulic and acid fracturing with proppant were measured under simulated high pressure and temperature reservoir condition to evaluate this new technique.Experimental results show that a good conductivity can be realized by composite acid fracturing combined hydraulic and acid fracturing with proppant on carbonate reservoirs.Based on the experiment results,a field work was successfully conducted,in which the composite acid fracturing scheme were designed and optimized on four different wells with a 100%success rate.The resulting great production increasing effect sustained the utilization potential of the composite acid fracturing on carbonate reservoirs.