辽河盆地于楼油层地质体的分类评价

CLASSIFIED EVALUATION OF THE GEOLOGICAL BODIES IN YULOU OIL RESERVOIRS OF LIAOHE BASIN

蒸汽吞吐开采进入后期,储层非均质性对开发效果的影响日益凸显。以辽西凹陷某试验区为例,综合多种资料,开展储层地质体分类研究,为稠油热采储层蒸汽吞吐转蒸汽驱提供地质依据。优选充分反映储层地质体特征的有效厚度、净总厚度比、孔隙度、渗透率、渗透率变异系数和夹层频率等参数,将目的层地质体划分为A、B和C 3类。利用地质统计分析的方法,对YⅠ层和YⅡ层共470个有效数据点进行统计分析,完成地质体分类评价。从分类结果看,不同类型地质体平面分布明显受沉积微相控制,YⅠ层以A、B类地质体为主,YⅡ层以C类地质体为主。地质体分类结果与开发效果匹配较好,蒸汽驱开发效果受地质体控制:A类地质体所在区域的蒸汽驱开发效果较好,C类的通常蒸汽热采开发效果较差,B类的介于上述两者之间;扩大试验区的蒸汽驱应以A类地质体发育的区域为重点。

With the steam soaking turned into the later period, the influences of the reservoir heterogeneity to the reservoir development effects are more and more remarkable. Taking the testing block in Yulou oil reservoirs of Liaoxi Sag as the example, by means of the comprehensive data, the sorted study on the geological bodies of the reservoirs is conducted so as to provide the geological evidences for the steam flooding inverted from the steam soaking of the thermal-flooded heavy oil reservoirs. Through the optimization of the following parameters which can fully characterize the geological body features： effective thickness, net total thickness ratio, porosity, permeability, permeability variation coefficient, interlayer frequency and so on, the current geological bodies are divided into three types： A, B and C. With the help of the geological statistics analysis, 470 effective data points in YI and YII are summed up and figured out, thus the sorted evaluation of the geological bodies is completed. The sorted results show that the planar distributions of the different types of the geological bodies are obviously controlled by the sedimentary microphases, Layer YI is mainly composed of Type A and Type B geological bodies, while Type C geological bodies are generally distributed in Layer YII. There are much better match between the sorted results and development effects, the effects of the steam flooding are dominated by the geological bodies ： the effects of steam-flooded Type A geological bodies are much more perfect, those of Type C are the worst, Type B is in the middle; the enlarged steam-flooding block is principally focused in the well-developed region of Type A geological bodies.