柴达木盆地昆北地区路乐河组砂砾岩有效储层发育主控因素及分布规律

柴达木盆地昆北地区路乐河组砂砾岩储集体非均质性强，明确砂砾岩体内有效储层发育的主控因素及分布规律是油藏勘探开发中亟待解决的关键地质问题。本文主要利用了区内路乐河组大量钻井岩芯分析资料，应用储层量化地质研究方法对该问题进行了探讨。首先根据试油、岩芯油气显示与物性之间的分布关系，对砂砾岩体内有效储层进行量化识别，认识到渗透率是评价该砂砾岩是否为有效储层的决定性物性参数，确定的渗透率下限值约0.7×10-3 μm2（气测值）。其次，通过对有效储层发育控制因素的量化分析，确定泥质杂基含量是砂砾岩体内有效储层发育的主控因素，含量上限值约7%。最后，根据泥质杂基含量与沉积微相间的密切联系，揭示出砂砾岩体内有效储层主要为冲积扇辫状水道微相沉积，其在垂向上主要发育在单期冲积扇扇体的顶部，平面上在扇中区域呈大面积连片分布，并沿扇体辐射线方向向扇根和扇端地区呈条带状延伸和尖灭。该认识被近期钻探所证实，对下一步勘探开发部署具指导意义。

Dominant Factors and Distribution of Effective Reservoir in Sandy Conglomerate Bodies of Lulehe Formation in Kunbei Area,Qaidam Basin

As an important oil play in Kunbei area, Qaidam Basin, sandy conglomerate bodies of Lulehe Formation are characterized by strong heterogeneity. As a result, oil enrichment there is mainly under the control of distribution of effective reservoirs developed in sandy conglomerate bodies. Therefore, it is the key problem of petroleum exploration to identify the effective reservoir accurately and figure out its distribution. In this paper, the dominant factor of effective reservoirs in sandy conglomerate bodies is quantitatively studied. Firstly, we used the relationship between oil testing data and petrophysics, and the distribution of oil show in cores, permeability with the limit of 0.7×10-3 μm2 was identified as the decisive parameter for effective reservoirs. Secondly, based on quantitative analysis of factors controlling reservoir formation, matrix content with the limit of 7% was identified as the dominant factor for effective reservoirs in sandy conglomerate bodies of Lulehe Formation. According to the conclusions above, and the relationship between matrix content and mircofacies, the effective reservoirs in sandy conglomerate bodies of Lulehe Formation were deposited by braided channels of alluvial fans, which mainly developed in the upper of single period fan body vertically, and thinning out from the middle to the root and edge zones along the fan radial line horizontally.