松辽盆地南部十屋断陷成岩作用

Diagenesis of the Shiwu fault depression in southern part of Songliao basin

通过取心观察,利用普通和铸体薄片、扫描电镜、阴极发光和油层物性等分析测试数据,对松辽盆地南部十屋断陷成岩作用次生孔隙发育特征进行深入研究.结果表明,十屋断陷深部断陷层的成岩作用类型较全,经历了强烈的压实作用和胶结作用、复杂的交代作用和多期次的溶解作用.根据成岩场分析和成岩作用研究结果,十屋断陷碎屑岩成岩作用划分早、中、晚3个成岩阶段.断陷层主要处于中成岩阶段,该阶段有机质成熟、黏土矿物转化、烃类与铝硅酸盐矿物的热化学反应等造成的酸性地层水,使储层在纵向上发育3个次生孔隙发育带,形成孔隙度相对较高的优质储层,是主要的油气储集空间.

According to the observation of the well core samples and based on the data analysis of normal and casting thin section, scanning electron microscope, cathodoluminescence microscope and oil layer’s physical property etc., the diagenesis and secondary porosity characters of the Shiwu fault depression are intensively studied in southern part of Songliao basin. The results indicate that the diagenetic types are various and the reservoir experienced intensive compaction, intensive cementation, complicate alternation and polyphasic solution. The diagenesis of clastic rock can be divided into early and middle and late diagenetic stages as revealed by the analyses of diagenetic field and the result of diagenesis. The fault depression layer is at a period of the middle stage in which the acidic formation water formatted by thermo-chemical reaction of organic material mature, sialite conversion, hydrocarbons with aluminum silicate minerals create three secondary porosity zones vertically in reservoir which forms the high-quality reservoirs with higher porosity, and they are the mainly accumulating room for oil and gas.