于奇西地区砂泥岩薄互层反演方法应用研究

Study of inversion methodology of thin sand-shale interbed in Yuqixi area

（中国石油化工股份有限公司西北油田分公司勘探开发研究院，新疆乌鲁木齐830011）

Exploration and Development Research Institute, Northwest Oilfield Company, SINOPEC, Urumqi 830011, China

于奇西地区三叠系上油组埋藏深，井控程度低，且为砂泥岩薄互层，储层物性变化大，储层与围岩在声波曲线上没有明显的差异，采用常规资料难以进行准确储层预测和评价。为此，在于奇西地区开展了反演方法储层预测研究。对各种反演方法进行了分析，认为基于重构技术的反演方法比较适应于奇西地区的特点。利用自然电位曲线重构了拟声波曲线，进行了伪波阻抗反演，获得了显著的地质效果，反演剖面清晰地描述了砂泥岩薄互层。利用反演结果，综合构造、沉积、油气成藏主控因素等信息，确定了上油组含油层①号砂体的分布范围和油气有利分布层段。

The upper oil unit in the Tertiary oil reservoirs in Yuqixi area is characterized by deep buried depth, poor well control, thin sand-shale interbed, significant variation in physical properties, and no obvious difference between the reservoirs and adjacent rocks on acoustic wave logging curves. So it is difficult to accurately predict and evaluate the reservoirs with conventional data. In order to solve this problem, a study is performed on methodology of reservoir prediction through inversion in Yuxiqi area. Analysis of various inversion methods shows that reconstruction-based inversion method is applicable in Yuxiqi area. Pseudo-acoustic curve was reconstructed by SP curve for inversion of pseudo-acoustic impedance. Good geologic effects were achieved, and the thin sand-shale interbeds are clearly defined on inversion sections. The distribution of No.1 sandbody and the favorable oil/gas reservoir intervals in the upper oil unit are identified by using the inversion results with the information of structures, sedimentary facies, and the main control factors of hydrocarbon accumulation.