楚州盐穴储气库建库地质条件分析

ANALYSES ON THE GEOLOGICAL CONDITIONS OF BUILDING THE SALT CAVERN GAS STORAGE IN CHUZHOU

楚州盐矿毗邻中俄东线天然气管道。在分析地震解释、资料井及老井钻探资料的基础上,为筛选出储气库建库层段,对该地区构造形态、地层特征、断裂发育、盐层横纵向展布、盖层密封性等地质条件进行了综合分析。该地区构造形态相对简单,浦二段上盐亚段第三岩性组合含盐厚度大,品位高,夹层少,盐层分布稳定,适合建设盐穴地下储气库。张兴区块盐岩含量分布稳定,夹层少,不溶物含量小,是建库有利区。通过分析各个盐群的地质情况,选取Ⅲ-7—Ⅲ-9盐群为建库有利层段进行储气库先期建设;杨槐区块目前只有一口资料井,待其地质资料进一步明确后再确定储气库建设层段。

Chuzhou salt mine is near to the Sino-Russian Eastern Route Gas Pipeline. In order to select the strata and member for the salt cavern construction, on the bases of the seismic interpretation, the information well and old well drilling data, the comprehensive analysis was conducted on the following geological conditions： the structural shapes, stratigraphic characteristics, fault development, horizontal and vertical distributions of the salt layers, seal- ing ability of the caprock and so on. The overall structure shape in the region is relatively simpler, the salt-bearing thickness in Group K2P（2-3（3） is pretty higher, the quality is higher and with few interlayers, the distribution of the salt group is stable, so it is feasible to construct the gas storage in the underground salt cavern. The salt-concentra- tion distribution is stable in Zhangxing Block characterized by less interlayers and low insolubles content, therefore the region is considered as the favorable area to build the gas storage. By means of the geological analyses on each salt layer, Salt Group Ⅲ-7-Ⅲ-9 were selected to construct first, because there is only one exploratory well in Yan-ghuai Block, The constructed layer and member should be determined after further making clear of the geological data.