安塞致密油藏混合水体积压裂技术研究与应用

Research and application of mixed water volume fracturing technology in tight reservoir,Ansai Oilfield

逄仁德¹ 韩继勇¹ 崔莎莎¹ 罗晶晶²

西安石油大学石油工程学院，陕西 西安 710065 中国石油川庆钻探工程公司长庆井下技术作业公司，陕西 西安 710018

School of Petroleum Engineering, Xi′an Shiyou University, Xi′an 710065, China CCDC Changqing Downhole Technology Company, CNPC, Xi′an 710018, China

安塞油田已进入开发后期，单井产能和采收率逐渐降低，为了老油田的持续发展，充分挖掘渗透率小于0.1×10^-3　 μm²的致密油藏的资源潜力，已成为安塞油田后期开发改造的主攻方向。借鉴北美致密储层的开发经验，针对鄂尔多斯盆地致密储层特性，按照“体积压裂”理念，在传统压裂方式的基础上改进创新，开展了混合水体积压裂技术攻关试验。通过混合水压裂，迫使天然裂缝张开，在主裂缝形成的同时，天然裂缝不断扩张，伴随脆性岩石的剪切滑移，实现对天然裂缝、岩石层理的贯通，形成较大的缝网系统，更大程度地扩大泄油面积，提高单井产量。现场实践对比表明，改造后裂缝体积增加40%，油井单井产油量提升30%。该技术为实现安塞油田致密油藏有效开发提供了技术支持。

As Ansai Oilfield is entering the late stage of development, both the single well production and recovery decrease gradually. Exploiting resource potential of tight reservoir with permeability less than 0.1 md has become the main direction of late development in Ansai Oilfield. According to the volume fracturing conception, the oilfield has carried out mixed water fracturing technology research to improve the traditional fracturing technology referring tight reservoir development experience of North America and the reservoir character of Ordos Basin. Natural cracks are opened and main cracks are formed by the mixed water fracture, at the same time, natural cracks continue to spread with the shearing slip of brittle rocks. Site practice shows that fracture volume increases by 40% and the single well production improves by 30% after improvement, which provides powerful technology support for efficient development for Ansai tight reservoir.

10.6056/dkyqt201504028