鄂尔多斯盆地长7致密油开发试验及认识

The Experiment and Recognition of the Development of Chang 7 Tight Oil in Ordos Basin

鄂尔多斯盆地长7致密油层具有物性差、地层压力系数低、天然裂缝发育和脆性指数较高四大特征。为实现该类致密油的经济有效开发,通过大量的室内研究及矿场试验,从提高初期单井产量、较长时间稳产、降低成本3个方面开展了研究。经过4个阶段的技术攻关,形成了针对低压致密油藏有效开发的关键技术——水平井体积压裂储层改造技术、水平井开发技术政策优化、降本增效技术,并得出4个方面主要认识:一是长水平段+体积压裂是提高单井产量的核心;二是初期长水平段体积压裂准自然能量开发+后期能量补充是目前可经济有效开发的方式;三是水平井控制压差采油有利于提升致密油的开发效果;四是降本增效是致密油经济有效开发的重要途径。

Chang 7 tight oil is characterized by poor physical properties,low formation pressure coefficient, well-developed natural fractures and high friability. In order to realize the goal of effective development with low-pressure tight oil,research has been carried out on three aspects to improve the early stages of single well production,stabilize for long time and reduce the cost through a series of field tests. After the four-stage technical innovation, great breakthrough has been achieved on tight oil development test, key technology for low-pressure tight oil has been established such as reservoir reconstruction technology of horizontal well volume fracturing, horizontal well development technique policy optimization, technology of reducing cost and increasing economic benefits,and four aspects of main knowledge have been gained as fol- lowing：（1 ）long horizontal length plus volume fracturing are the core of promoting well production;（2）cur- rently it is preferable to utilize approximate natural energy at the initial stage and energy supplement at lat- er stage for horizontal wells with long horizontal length,volume fracturing; （3）controlled oil production is beneficial to promote tight oil development effects; （4）cost reducing and efficiency-enhancing are important ways of exploiting tight oil economically and effectively.