中东地区碳酸盐岩油藏分类评价方法与注水开发对策

针对中东地区碳酸盐岩油藏类型复杂多样、缺乏分类开发模式指导的问题，提出基于主成分双标图和K-均值聚类图的油藏分类评价方法。采用定性分析与多元统计分析相结合，从16个典型碳酸盐岩油藏中选取能够反映岩石学、储集层结构、储集层物性、隔夹层、流体性质及非均质性的8个油藏特征参数并构造数据矩阵，然后应用奇异值分解协方差矩阵实现主成分分析，进而构造主成分双标图，对油藏、油藏特征参数及两者关系进行图解分析，最后结合K-均值聚类法开展油藏分类评价。研究结果表明：微观孔隙结构、储集层厚度和非均质性等关键参数对油藏的区分能力较强，据此将中东地区碳酸盐岩油藏划分为3种类型。薄层碳酸盐岩油藏内部贼层不规则分布导致水平井水淹严重，厚层层状碳酸盐岩油藏纵向物性差异大影响储量动用程度，巨厚似块状碳酸盐岩油藏微观孔隙体系复杂且隔夹层发育"隐蔽"、强非均质性加剧了1套层系笼统开发的矛盾。基于此，有针对性地制定了薄层油藏水平井井网低注高采、厚层层状油藏边缘递进和巨厚似块状油藏利用隐蔽隔夹层分层系注水的开发对策，为中东地区碳酸盐岩油藏高效注水开发实现上产稳产提供一定技术支持。

Classified evaluation methods and waterflood development strategies for carbonate reservoirs in the Middle East

In view of the fact that there is no guidance for the classified development mode of complex and diverse carbonate reservoirs in the Middle East, a classified evaluation method of oil reservoirs was proposed based on principal component biplot and K-means clustering diagram. Through the combination of qualitative analysis and multivariate statistical analysis, 8 reservoir characteristic parameters that can reflect petrology, structure and physical properties of carbonate reservoir, interlayers, fluid properties and heterogeneity were selected from 16 typical carbonate reservoirs, based on which a data matrix was constructed. Later, principal component analysis was achieved by the singular value decomposition of covariance matrix, and then the principal component biplot was constructed for the graphic analysis of reservoirs, reservoir characteristic parameters and the relationship between the both. Finally, the classified evaluation of reservoirs was conducted using the K-means clustering method. The results show that key parameters such as micro-pore structure, reservoir thickness and heterogeneity have a strong ability to distinguish the reservoirs, so that the carbonate reservoirs in the Middle East can be divided into 3 types accordingly. The irregular distribution of thief layers in thin reservoirs has led to serious water-out performance in horizontal wells. The great difference in vertical physical properties of thick layered reservoirs has an adverse influence on the degree of reserve utilization. The super-thick massive reservoirs are characterized by a complex micro-pore system, subtle interlayers, and strong heterogeneity, which have intensified the contradiction in the general development of commingled water injection. Based on this, the paper proposes the development strategies including bottom interval injection and top interval production with horizontal well patterns for thin reservoirs, progressive peripheral water injection for thick layered reservoirs, and separated layer water injection with hidden baffles and barriers for super-thick massive reservoirs, thus providing technical support for the efficient waterflood development of carbonate reservoirs in the Middle East.