地震反射特征分析技术在HJQ区块储层预测中的应用

APPLICATION OF SEISMIC REFLECTION FOR RESERVOIR PREDICTION IN HJQ AREA

研究区位于鄂尔多斯北部的伊陕斜坡和HJQ断阶带上。前期综合研究认为该区具有一定的勘探前景,但由于该区天然气成藏因素复杂,目前的勘探成功率仅为25%左右。提高勘探成功率和寻找成藏特点是该区当前需解决的主要问题。通过分析工业气流井与干井之间的源岩及储层的反射特征、展布规律以及测井曲线特征,找出其间存在的特征差异,总结3种反射特征模式,指出该区构造背景上具有目的层段下倾方向反射能量强,相位连续性好,同相轴粗细均匀,地层上倾方向有同相轴合并或终断特点的部位是油气储集最有利部位,成藏几率大,指出该区成藏与否与井区源岩的发育程度关系不大,而与构造圈闭的存在与否和储层的横向变化密切相关,即构造圈闭是成藏的必要条件,岩性圈闭是成藏的关键。为下步部署钻井提供新的思路和勘探目标。

HJQ（Hangjinqi） area is located in the Yishan slope and HJQ stepfault zone in northern Or dos. In spite of some previous researches for targeting favorable prospects, the exploration success rate is approximately 25 % because of a complicated gasbearing mechanism in this area. The main problem lies in how to improve the exploration success rate and to make clear the mechanism of hydro carbon accumulation. Through analyzing the reflections, distributions and characteristics of logging curves for source rocks and reservoirs in both industrial gas wells and dry wells, we have found out their distinctions of reflectance and given a summary of three reflectance signatures. By using seismic cross hole reflection technique, it shows that the target has a strong reflection, consistent phase con tinuance and proper events display in the down dip direction within the tectonic setting; it also proves that where the events are merged or thinned out in the up dip direction it is the most favorable location for oil and gas accumulation. Thus, it concludes that hydrocarbon accumulations depend less on the degree of development of source rocks, but more on the existence of structural traps and lateral varia tions of reservoirs; that is, structural trapping is prerequisite for hydrocarbon accumulations, while depositional trapping essential. All researches discussed in this paper can be taken as a database and reference for the next round drilling project.