BZ油田古近系储层沉积过程数值模拟

Numerical simulation of sedimentary process for Paleogene reservoir in BZ Oilfield

BZ油田古近系储层埋藏深,地震资料分辨率低,储层沉积模式认识不清,使得开发方案编制面临挑战。综合应用地震、测井和岩心分析资料,通过量化沉积体系发育的主控因素,开展三维沉积过程数值模拟。结果表明:古近系沉积时,共有南西和北东2个方向沉积物源向湖盆中心共同汇聚,其中南西方向物源供给速率大,砂体分布范围广;湖盆充填演化过程中,纵向上发育4期砂体,晚期形成的2期砂体分布面积大,且两侧物源在湖盆中心交汇。以沉积模型作为约束条件,运用三维地质建模技术建立储层岩相分布预测模型,并用新钻的2口评价井对模型进行可靠性评价。钻后结果表明,储层砂体预测符合率达到90%以上。

With deep burial reservoir of Paleogene, low seismic data resolution, poor recognition of reservoir sedimentary pattern, the development plan is facing challenge. Using seismic, log and core analysis, quantified main control factors of sedimentary, 3D sedimentary process is simulated numerically. The study shows that the sedimentary sources in the two directions of southwest and northeast converge at the center of the lake basin during sedimentary of Paleogene reservoir. In the direction of southwest, the supply rate was lager and sand distribution area was great. During lake sedimentary evolution, four- stage sand body developed vertically, distribution area of sand was great in the last two stages and the source of the two sides met at the center of the lake basin. Taking sedimentary model as the constraint conditions and using 3D geological modeling technology, reservoir lithology distribution prediction model was established, and two new drill appraisal wells were used to evaluate the reliability of the model. The drilling results show that the prediction coincidence rate of reservoir sand body is above 90%.