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对胜利油田疏松砂岩稠油油层中孔隙结构分布及油、水赋存状态进行研究,选取济阳坳陷沾化凹陷馆下段疏松砂岩稠油油藏岩样,开展岩心微米尺度的CT扫描检测,利用油水散失校正后的岩心分析残余油水饱和度,对CT扫描图像进行反演标定,确定了不同流体的灰度区分界限值,认为疏松砂岩稠油储层具有与传统认识不同的油水赋存特征.结果表明:水的灰度区分界限值范围为4 000~4 800;油的灰度区分界限值范围为0~4 000.在稠油储层岩样中除了连通性好的储油孔隙外,存在另外两类孔隙,其中油水赋存形式分别为“分隔水滴”和“孤立油滴”.这种稠油油层孔隙分布及油水赋存状态可以较好地解释稠油油藏开发初期即出水的现象,测井解释稠油油层含油饱和度通常比实际密闭取芯值大5%,而稠油油藏构造较低部位井投产初期含水量达到40%以上,也不意味着开采层位到了油水界面,这为修正测井解释饱和度及后期油层有效开发井位部署提供了依据.
The distribution of pore structure and oil and water occurrence in the unconsolidated sandstone heavy oil reservoirs in Shengli Oilfield were studied. The rock samples of unconsolidated sandstone heavy oil reservoirs in the lower section of Zhanhua depression in Jiyang depression were selected to carry out CT scanning on core micrometer scale. Based on the residual oil-water saturation of the core corrected by oil-water loss correction, the CT scanning images were inverted and calibrated to determine the boundary of the grayscale discrimination of different fluids. It is considered that the unconsolidated sandstone thick oil reservoirs have the characteristics of oil and water that are different from the traditional understanding The results show that the threshold range of water grayscale discrimination is from 4 000 to 4 800 and the range of grayscale discrimination of oil ranges from 0 to 4 000. In addition to the well-connected reservoir pores , There are two other kinds of pores, of which oil-water forms are “separated water droplets” and “isolated oil droplets.” The pore distribution and oil-water occurrence state of heavy oil reservoirs can well explain heavy oil reservoirs In the early stage of development, the water was discharged. Log interpretation explained that the oil saturation of heavy oil reservoirs was usually 5% larger than the actual closed coring values. However, the water content of the wells with the lower part of heavy oil reservoirs was put into operation more than 40% Mining horizon to the oil and water sector This provides the basis for the revised log interpretation saturation and post-effective reservoir development wells deployment.