海安凹陷XJ地区泰一段第二亚段地层圈闭识别方法

Identification method of stratigraphic trap in K_2t_1~2 of XJ area,Hai'an Sag

XJ地区泰一段具备形成多种油藏类型地质条件,在探索地层超覆圈闭的勘探研究中,面临单砂体厚度薄、地震分辨率不足以定量预测砂体的难题。通过沉积相分析和预测方法攻关,提出地层等厚反推法和波形指示反演法厘定了泰一段第二砂层组砂岩尖灭线,有效定量预测砂体厚度变化规律,明显提升了砂体预测精度,进而发现和落实了地层圈闭。

K_2 t1/2 of XJ area has geological conditions for forming various types of reservoirs. In the exploration of strati- graphic overlap trap, it is difficult to predict sand bodies quantitatively when the thickness of a single sand body is thin and the seismic resolution is not enough. By means of the sedimentary facies analysis and the prediction method, the equal thickness inverse method and the waveform indication inversion method are proposed to determine the sandstone pinchout line of K_2 t1/2. The quantitative prediction of change in sand thickness effectively improves the prediction accuracy of sand body. Stratigraphic traps have been discovered and fulfilled.