松辽盆地北部油田精细构造识别和应用

Identification and Utilization of Fine Structure in High Water-Bearing Reservoir of Northern Songliao Basin

精细构造研究是随着高分辨率开发地震技术和油田的深度开采而产生的。由构造应力作用形成的微幅度构造、以沉积作用为主形成的储层微型构造 ,都属于精细构造的研究范畴 ,但二者在成因、识别方法上有所差异。大庆油田在高含水开发后期 ,利用高分辨率三维开发地震技术 ,对微幅度构造进行研究 ;进而在地震剖面上 ,识别出以前不能识别的微幅度构造 ,尤其通过滑动相关、倾角扫描和关联维等方法识别井间小断层 ;利用测井资料 ,研究储层微型构造 ,又通过微型构造图和趋势面剩余分析方法 ,描述对单层的层面起伏程度和形态。这些对打井找油和剩余油研究都具有重要意义。

Identification and utilization of fine structure are required in high water-bearing phase of oilfield development using the high-solution seismic technology. Fine structures include low amplitude structure and reservoir mini structure, but they differ in formation and require different methods in identification. Low amplitude structure can not be determined in seismic profiles by ordinary data processing and interpretation. Utilizing 3-D high-resolution seismic technique, low amplitude structures, which consist of small size and small area structural deformation, low fluctuation and tilt, and so on, can be identified in seismic profiles. While reservoir mini structure are formed in sedimentation and related to sedimentary environment, different compaction and paleo-topography. The top and bottom of oil layers are not even with small local fluctuation and tilt.The late development phase of Daqing Oilfield is characterized by high water-bearing reservoir. Based on the 3-D high-solution seismic technology, low amplitude structures are focused on. The identification methods of low amplitude structure include semi-automatic layer tracing, velocity scanning for calculating velocity, structure trend analysis and automatic identification of small fault. Especially with the methods of slip correlation, dip angle scanning, relative dimension, the small faults in formation can be identified. The effect factors of identification include seismic processing and interpretation. These methods were applied to Yushulin oilfield of Daqing to predict small fault as well as to determine the plan of exploration and development. According to close spacing well logging data, utilizing mini structure plot and trend surface remaining analysis, the fluctuation extent and shape of bedding plane of reservoir can be described in detail. Ploting the structure contour is the key to identify reservoir mini structure. The effects of sedimentary micro-facies , boundary of sedimentary unit, topography and tilt of well are taken into account. Combination of reservoir mini structure and sedimentary micro-facies can be used to determine the relatively abundant areas of remaining oil. At the later high water-bearing development stage of heterogeneous sand body oilfield, study of the identification method of fine structure and presentation effect factors of identification process are used to understand the heterogeneity of reservoir and establish the fine structure model, which can be used to predict the distribution of remaining oil and locate effective wells.