吐哈盆地丘东气田中侏罗统西山窑组上、下气藏储层差异性分析

Analysis of reservoir differences between upper and lower gas pools of the Xishanyao Formation of Middle Jurassic in Qiudong Gasfield,Turpan-Hami Basin

吐哈盆地丘东凝析气田主力产层为中侏罗统西山窑组中部的砂岩层,可分为上气藏(X4-X5)和下气藏(X6-X9),上、下气藏的储集体虽然都是三角洲前缘的河口坝和分流河道砂体,但在储集物性、非均质性和砂体几何形态等方面存在明显的差异。本文通过基准面旋回的划分和沉积微相研究,指出上、下气藏因其所处的旋回位置及相分异作用不同,储层非均质性和砂体几何形态存在明显差异,上气藏储层物性明显优于下气藏。该研究表明,基于基准面变化的高分辨率层序地层学方法可有效地用于预测储层的纵横向分布,对油气藏开发部署有重要的指导意义。

The main pay zones in the Qiudong condensate gasfield of Turpan-Hami Basin are sandstone intervals in the middle part of Xishanyao Formation of Middle Jurassic, which can be divided into two gas pools, the upper pool （ X4 - X5 ） and the lower pool （ X6 - X9 ）. Though reservoirs of the upper and lower gas pools are both mouth bar sandstones and distributary channel sandstones, there are evident differences in their petrophysics, heterogenity and geometric characteristics. The upper gas pool and the lower gas pool were in different locations during the base-level cycle and had different effects by different facies differentiation, thus they had obvious differences in reservoir heterogenity and sandbody geometric characteristics. The results show that the petrophysical properties of the upper gas pool are obviously better than those of the lower gas pool. High resolution sequence stratigraphy based on the base level cycle can be effectively applied to the prediction of lateral and vertical distribution of reservoirs and is profitable for exploration and development of petroleum reservoirs.