塔中地区含砾砂岩段隔夹层特征及分布规律

塔中4油田含砾砂岩段发育的隔夹层严重阻碍了油田的开发。在岩心、薄片观察基础上,结合前人研究,总结出本区隔夹层的成因主要有3大类7小类。根据岩性、电性、物性、产状、宏观展布等,进一步将不同成因的隔夹层分为泥粉质隔夹层、钙质隔夹层、物性隔夹层,并厘定了非取心井段隔夹层识别的物性、电性标准。最后基于单井解释,揭示了隔夹层的发育与沉积环境、沉积旋回、断层的关系:随着沉积水体逐渐加深,物性隔夹层从5小层至1小层迅速减少,而泥粉质隔层则相反;在每一个基准面上升旋回,顶部容易发育泥粉质隔夹层,底部容易发育物性隔夹层;钙质隔夹层则受断层控制。

Characteristics and distribution of interlayer in gravel-bearing sandstone segment in Tazhong area

The interlayers developed in the gravel-bearing sandstone segment of Tazhong 4 Oilfield have seriously hampered the development of the oilfield. Based on the observation of cores and thin sections, combined with previous studies, this paper concludes that there are three major categories and seven subcategories of the origin of the interlayer in the study area. According to lithology, electrical properties, physical properties, occurrence and distribution, the interlayers with different origins are further divided into silty interlayers, calcareous interlayers and physical interlayers, and the physical and electrical standards for identifying the interlayers in non-coring wells are determined. Finally, based on the single well interpretation, the relationship between the development of the interlayer and the sedimentary environment, sedimentary cycle and faults is revealed. With the deepening of water, the physical interlayers decrease rapidly from 5 to 1 sublayer, while the silty interlayers increase; In each base-level descending cycle, the silty interlayers are easy to develop at the top, while the physical interlayers are easy to develop at the bottom; The calcareous interlayers are controlled by faults.