松辽盆地葡萄花油层低阻特征及成因机理研究

松辽盆地葡萄花油层广泛发育低阻油层,具有广阔的开发前景,但其形成受较多因素影响,机理复杂,识别难度大,仅从常规测井上难以区分油层和水层,大大限制了该类油层的挖潜。针对该难点,从低阻油层的特征分析出发,从外部和内部7个因素分析了低阻油层的成因机理。研究结果表明:沉积相带和黏土矿物类型、含量、分布形式是该区低阻油层发育的主控因素,构造、孔隙结构以及砂泥岩互层对该区低阻油层发育也有一定的影响,泥浆侵入和油水层矿化度对低阻油层基本无影响。研究成果在低阻油层识别现场实践中取得了较好的应用效果,为该类油层的评价、识别和潜力区预测提供了较为可靠的地质基础,对于该区的增储上产具有重要的现实意义。

Study on Low-Resistivity Characteristics and Genetic Mechanism of Putaohua Oil Layers in Songliao Basin

The Putaohua oil layers in the Songliao Basin are widely developed with low resistivity and has broad development prospects. However, their genesis is affected by many factors, their mechanism is complex, and they are difficult to be identified. Hence, it is hard to distinguish oil layer from water layer only from conventional well logging, which greatly limits the tapping potential of this kind of oil layer. In view of this difficulty, starting from the analysis of the characteristics of low-resistivity oil layers, the genetic mechanism of the low-resistivity oil layers was analyzed from 7 external and internal factors. The results show that sedimentary facies belt and clay mineral type, content and distribution form are the main controlling factors for the development of low-resistivity oil layers in this area. Structure and pore texcture, and interbedding sandstone and mudstone also have certain influence on the development of low-resistivity oil layers in this area, while mud invasion and salinity of oil-water layers have little influence on them. The research results have achieved good application results in the field practice of low-resistivity oil layer identification, which provides a more reliable geological basis for the evaluation and identification of this type of oil layers and the prediction of potential areas, and has important practical significance for increasing reserves and production in this area.