塔河油田九区三叠纪下油组夹层识别及分布规律

Interlayer identification and distribution of Triassic lower oil group in block 9 of Tahe oilfield

为研究塔河油田九区三叠纪下油组厚砂体内部夹层识别与分布,综合岩心、测井及动态资料,结合水平井电阻率曲线反演识别夹层,利用直井和水平井联合控制的方法进行夹层识别及夹层井间分析。根据夹层参数定量统计分析及沉积相分布,分析夹层的空间分布规律。结果表明:研究区夹层主要为泥质夹层和钙质夹层两类,通过单井定性识别及水平井电阻率曲线反演综合确定夹层的平面分布范围,平面上夹层大小不一、分布比较零散、连续性差,呈薄厚不等的透镜状、长条状。泥质夹层受沉积微相控制,顺物源北东方向展布,主要为辫状河三角洲平原和辫状河三角洲前缘分流河道边部溢岸沉积;钙质夹层相对较发育,主要分布于辫状河三角洲前缘沉积环境中。夹层分析结果为后期剩余油分布研究提供参考。

The interlayer identification and distribution in thick sandstone of Triassic lower oil group in block 9 of the Tahe oilfield are not clear enough. Based on detailed observation of core,well-logs and dynamic data,combined with the resistivity curve inversion of horizontal well,the interlayer identification and inter-well contrast analysis in the block 9 are studied by the vertical well and the horizontal well. On that basis,combined with the quantitative statistical analysis of interlayer parameters and the distribution of sedimentary facies,the spatial distribution of interlayer is analyzed. The result shows that the interlayer in the study area can be classified into two types of muddy and calcareous,and the plane distribution range of the interlayer is determined through the qualitative identification of single well and the resistivity curve inversion of horizontal well. Interlayers are lenticular and long striped with the thickness and the sizes are different,and the distribution is scattered and the continuity is poor. The muddy interlayer mainly belongs to the over-bank sediment of the distributary channel in the braided river delta plain and the braided river delta front,controlled by sedimentary microfacies,and distributes along the source. However,the calcareous interlayer is relatively developed and mainly distributes in the braided delta front sedimentary environment. The interlayer analysis results provide reference for the research of remaining oil distribution in the later period.