鄂尔多斯盆地低渗-致密气藏水平井全生命周期开发技术及展望

Technologies and prospect of full-cycle development of low-permeability tight gas reservoirs with horizontal wells,Ordos Basin

基于鄂尔多斯盆地天然气开发实践,系统描述了低渗-致密气藏地质特征。依据水平井开发的主要对象、技术参数和生产指标等因素,将水平井开发历程划分为实践探索、攻关试验、规模应用和优化提升4个阶段。详细阐述了鄂尔多斯盆地水平井开发的技术内涵,系列开发技术包括多学科甜点优选技术、多层系大井丛整体部署技术、多专业融合导向技术、精细化压裂改造技术以及全生命周期生产管理。综合评价了不同气藏水平井的开发效果及潜力,认为致密气水平井具有良好的开发效果和前景;明确了加强多学科全过程联合研究是水平井技术发展的主要方向,也是实现低品位天然气资源规模、效益开发的关键。今后面对深、薄、低丰度等更为复杂的开发对象,将针对性地优化、提升苏里格等老气田水平井技术,攻关形成庆阳、宜川等新气田水平井配套技术,超前储备页岩气、煤层气等新型天然气资源水平井有效开发技术,为鄂尔多斯盆地天然气上产及稳产提供技术保障。

The geological characteristics of low-permeability tight gas reservoirs(developed mostly with horizontal wells)in the Ordos Basin are systematically described based on previous gas development experiences.A successful development of these reservoirs with horizontal wells usually comprises four stages based on a study of the targets,technical parameters,and performance indicators of the wells:exploring all possibilities,tackling technical problems,scaling up of technology implementation as well as optimization and improvement.The technical connotation of horizontal well development in Ordos Basin is elaborated and represented by a series of development technologies including multidisciplinary sweet spot optimization technology,overall deployment technology of multi-layer large well cluster,multidisciplinary integrated geosteering technology,and fine fracturing technology with a full life cycle production management.A comprehensive evaluation of gas development through horizontal wells from different types of gas reservoirs indicates that horizontal wells perform better in tight gas reservoirs,that strengthening the joint efforts on multi-disciplinary research for the whole process is the main direction of horizontal well technology development as well as the key to a large-scale development of low-grade natural gas resources with profit.For developing reservoirs with more complex conditions such as those buried deep in thin layers with low abundance of gas,horizontal wells will be further improved to deal with the challenges in the brown Sulige gas field where targeted optimization of the technology will be carried out,the green gas fields such as Qingyang and Yichuan where supporting technology will be developed,