吐哈盆地丘东洼陷层序基准面旋回与储集性能关系

通过对吐哈盆地台北凹陷丘东洼陷中侏罗统层序基准面旋回与储集层储集性能的对比分析认为，丘东洼陷短期基准面的升降对储集性能具有明显的控制作用，短期基准面上升，储集层储集性能变差；短期基准面下降，储集层储集性能则变好。将中侏罗统短期基准面旋回测井响应模型分为退积-退积型、退积-进积型、进积-退积型和进积-进积型等4种。同时认为，储集层物性随着中期基准面的上升，辫状河道沉积砂体变厚、粒级变粗、砂泥比增大；中期基准面下降、旋回，储集层物性明显变差。指出了相对优质储集层发育的层段对应于基准面较低部位的储集层，丘东洼陷纵向上J2X^4早期和J2s^2是岩性油气藏勘探的有利目标层位；平面上弧形带两翼为有利的岩性油气藏发育区。

Relationship Between Datum Cycle and Reservoir Quality in Qiudong Sub-Sag, Tuha Basin

The correlation of datum cycle and reservoir quality of Middle Jurassic in Qiudong sub-sag of Taibei sag in Tuha basin is made. The analysis shows that the short-term elevation of Qiudong sub-sag is of distinct control on reservoir quality. With the datum rising, the reservoir quality becomes poor;, contrariwise, it becomes good. Four types of the well log response models for the short-term datum cycle of Middle Jurassic are delineated such as retrogradation-retrogradation, retrogradation-progradation, pragradafionretrogradation and progradation-progradation ones. Also, with the mid-term datum rising, the braided river channd sand body is thickened, the sand grain size is getting coarser, with sand-shale ratio increasing. With the mid-term datum descending or cycling, the reservoir quality is getting poorer obviously. It is pointed out that the intervals with higher quality of reservoirs are corresponding to the reservoirs at the lower datum, so in Qiudong sub-sag, the Lower J2x^4 and J2s^2 could be favorable target zones vertically for lithologic oil-gas exploration; while two sides of its arc belt be advantageous zones laterally of developed lithologic oil-gas reservoirs.