文南油田文95断块区剩余油分布研究

A study on the remaining oil distribution in Block Wen95 of Wennan oil field

随着中原油田开发程度的不断提高,开发难度越来越大,主力油层相继进入高含水开发期。油藏开发中暴露出的问题是井网不完善、水驱控制程度低、层间矛盾突出、注水效果不明显。为了适应开发阶段的需要,了解和掌握油藏中剩余油的宏观和微观的空间分布,确定其剩余油储量、剩余可采储量,是油藏下部挖潜的重要依据。文95块沙三中油藏是文南油田最早投入开发且开发效果最好的区块之一。在精细油藏描述地质模型上,对油藏的开发状况进行分析,充分利用油水井产、注两个剖面、C/O比测井资料、调整井水淹状况分析评价,应用油藏数值模拟研究技术,将剩余油分布从定性化到定量化、可视化。通过对剩余油分布的定性和定量研究,结合影响剩余油分布的地质和开发因素,对文95块油藏剩余油分布特征进行了3方面的研究:未动用或少动用的油砂体形成的剩余油;已动用油层的平面剩余油滞留区;层内非均质形成的剩余油。图1参5（刘秋杰摘）

With the increasingly mature of development of Zhongyuan oil field, the development difficulty has become more and more remarkable. The main production layers have entered into the high water-cut development stage, while the main problems that the well patterns are not complete, the water-flooding control degree is low, the contradiction among layers is outstanding, the water-flooding result isn't tangible, and so on are more exposed. The main factors influencing water-flooding development are small-sized sand body, bad reservoir permeability and porosity, striking differential among layers, complex pore configuration, etc. In order to meet the needs of producing remaining oil, knowing and mastering the remaining oil's macroscopic and microscopic distribution, and then defining the remaining oil reserves and the recoverable reserves is the important ground for tapping reservoir potential. Using the fine reservoir geological model, the current development situation of the Block Wen95 was analyzed and evaluated, and then through taking full use of water and oil wells production and injection profiles, C/O logging data, adjustment well water-breakthrough analyses, and numerical reservoir simulation, the remaining oil distribution has been quantified and visualized. Through the quantified and qualified studies of the remaining oil distribution, and combined with the research on geological and development factors influencing remaining oil distribution, the article clarified the characteristics of the remaining oil distribution in Block Wen95 reservoir in three respects: first, the oil remained in the produced or less produced oil-bearing sand bodies; second, the oil remained in the retention area of the contracted layers; and third, the oil remained in the heterogeneous payzones of the reservoirs. This study explored a way to develop the remaining oil at the high water-cut stage, which can guide the development of the same type of reservoir.