关键词: 曲流河砂体, 内部构型, 地质建模, 油藏数值模拟, 剩余油分布, 挖潜措施

Abstract:

On the basis of the data from core analysis, well logging and production performance, the hierarchy analysis method combined with the model matching was applied to analyze the sedimentary units, sedimentary facies, single meandering belt, single point bar and lateral accretion bodies of meander sand bodies in the late stage of high water-cut under the condition of dense well-pattern in Daqing Oilfield. The scale and mode of the lateral accretion interlayer in the meander sand body were developed, and the four parameters for describing the modes of the lateral accretion interlayer including dip direction, dip angel, expanded range and horizontal range were determined. The 3D reservoir architecture model and physical property model were established by using the sequential indication simulation. The numerical reservoir simulation of real sand block based on the models was finished. According to the results of reservoir modeling and numerical simulation, the four patterns of remaining oil distribution in the meandering river reservoir at the late stage of high water-cut under the condition of the dense well pattern were summarized. The corresponding measures for increasing recovery of remaining oil controlled by the lateral accretion shale bedding were implemented. The results show that the width of the single meandering belt in North Saertu Oilfield is from 200m to 800 m, and the length of the point bar is from 120 m to 500 m. The dip angle of the lateral accretion interlayer is from 7° to 10°. The lateral accretion shale bedding extends downward to 2/3 of channel sand body in thickness. Good effect of injection-production relation in the single meandering belt of the designed Well 4-144 has been achieved. These measures can provide bases for tapping the potential of in-layer remaining oil during the late period of oilfield development.

Key words: meandering reservoir, inner architecture pattern, geological modeling, numerical reservoir simulation, remaining oil distribution, potential-tapping measures