裂缝性特低渗油藏井间化学示踪监测分类解释模型

裂缝性特低渗透油藏天然裂缝广泛发育，人工裂缝使其裂缝系统更加复杂多样。随着注水开发的深入，裂缝系统发生动态变化，现有的孔隙型示踪剂解释模型难以有效表征该类水窜裂缝系统。以鄂尔多斯盆地裂缝性特低渗透油藏为例，通过分析水窜、水淹综合特征，将水窜裂缝系统划分为人工裂缝窜通型、差异裂缝交互型和裂缝相对均匀推进型，等效抽象出不同水窜裂缝系统的物理模型，并依据注入水与示踪剂在裂缝条带中运动的基本假设，建立了Ⅰ类单峰型、Ⅱ类多峰型、Ⅲ类宽台型水窜裂缝系统的示踪剂分类解释模型，实现了非均质问题的相对均质化处理。现场实例验证了该分类模型在裂缝性特低渗透油藏示踪剂解释中的合理性和适用性，为裂缝性特低渗透油藏水窜、水淹治理方案的准确制定和后期精细挖潜提供重要依据，具有广阔的应用价值。

Classification and interpretation models of inter-well chemical tracer monitoring for fractured ultra-low permeability oil reservoirs

In fractured ultra-low permeability oil reservoirs, natural fractures are well developed, while artificial fractures make the fracture systems more complicated. As waterflooding is further promoted in development, the fracture systems change dynamically. The current porous tracer interpretation model cannot be used to effectively characterize such water-channeling fracture systems. In this paper, the general characteristics of water-channeling and water-flooded fracture systems were analyzed for the fractured ultra-low permeability oil reservoirs in the Ordos Basin. The water-channeling fracture systems were divided into three types, i.e. artificial fractures communicated, different fractures interacted, and fractures advanced evenly, and then the physical model was devised equivalently for each type of water-channeling fracture system. Based on the basic assumptions for movements of injected water and tracer in fracture strips, three classes of tracer interpretation models were established for water-channeling fracture systems, i.e. Class I (single-peak), Class II (multi-peak) and Class III (wide-platform). In this way, heterogeneity-related problems were treated as relative homogeneity. Field cases proved the rationality and applicability of these models in tracer interpretation for fractured ultra-low permeability oil reservoirs. The tracer classification and interpretation models can provide important evidences for accurately preparing the water-channeling and water-flooding treatment schemes and thoroughly tapping the potential of fractured ultra-low permeability oil reservoirs.