苏里格气田强非均质致密气藏水平井产气剖面

Production Profile of Horizontal Wells in Strongly Heterogeneous Tight Gas Reservoirs in Sulige Gas Field

为确定苏里格气田水平井分段压裂后各压裂段的产气能力,通过分析水平井产气剖面及其储集层非均质性、水平井渗流特征、多段压裂改造工艺、生产压差等因素影响,认为储集层物性和有效砂体发育程度是影响产气能力的主控因素,其作用大于理想模型中水平井跟部和趾端的渗流优势项作用;生产压差的增大,加剧了强非均质储集层各压裂段产气量的差异;分段压裂改造后,段内裂缝的不均匀分布,导致同一压裂段不同射孔簇的产气能力不同。因此,提出多段压裂水平井的射孔段优选、水平段差异化改造和段内暂堵裂缝均匀扩展的技术对策,以提高致密气藏的开发效果。

In order to determine the productivity of each fracturing section of a horizontal well after staged fracturing in the Sulige gas field,the production profile of horizontal wells and its influencing factors such as reservoir heterogeneity,flow characteristic,multistage fracturing technique and production pressure difference were analyzed.It is found that physical properties of reservoirs and development degree of effective sand bodies are the main factors controlling gas well productivity,and they have greater effect than the flow dominant term at the heel and toe of the horizontal well in an ideal model.The increase in production pressure difference aggravates the difference in gas production rate among fracturing sections in strongly heterogeneous reservoirs.The uneven distribution of induced fractures leads to different gas productivities of perforation clusters in the same fracturing section.Therefore,for multistage fractured horizontal wells,technical countermeasures such as optimization of perforation sections,differential stimulation of horizontal sections,and uniform fracture propagation by temporary plugging were proposed so as to improve the development effect of tight gas reservoirs.