中国东部W油田T区中浅层储层特征研究

Research on Middle-shallow Layer Reservoir Characteristics at T Area in W Oilfield in East China

W油田位于中国东部;该油田存在多套河道砂。通过井上统计,该区砂体厚度纵向变化快,3—20 m不等;且砂泥岩在常规波阻抗上难于区分,常规储层预测方法难于区分。在细分层基础上,通过交会分析,选取岩性敏感因子,建立了敏感曲线与声波曲线的关系,通过重构曲线进行波阻抗反演。以此为基础,在波阻抗体上设定砂泥岩区分的门槛值。通过立体透视方法,大于砂岩阻抗值的定义为砂岩。通过变色显示,对T组各砂体的平面展布特征进行了定量刻画。通过对比分析,认为该方法与现有钻探结果吻合度较高,证明了该方法在本区的适用性。同时研究结合区域构造、单井相等资料,对该区河道沉积的变迁的期次进行了初步分析。

W oilfield, located in the east of China, was characterized by its reservoirs＇ non-homogeneity. The reservoir sandstone developed irregularly, and its thickness, merely 3--20 meters, changes quickly in the field. In addition, the wave impedance characteristics of the sandstone and shale were similar in this district. It is difficult, or even impossible, to classify the sand and shale using the traditional reservoir inversion. According to the small layer division results and chose the favorable lithology sensitivity factors, the relationship between sensitivity curve with acoustic curve was build up and based on that the wave impedance inversion was done to the target layer again. Then the threshold values were marked on the cubic data of wave inversion . And the sand could be easily recognized from the three-dimensional perspective maps according to the threshold value. After that the reservoir distribution could be acquired directly. This results were proven by the drilling data and this method could be applied in this district also. Based on the regional structure evolution and the signal well facies, also the transition of the channel deposit is did preliminary analysed.