孤岛油田中二中区开发中后期微型构造研究

MICROSTRUCTURES DEVELOPED DURING MIDDLE-LATE STAGE OF OILFIELD DEVELOPMENT

从油田开发实际出发,系统总结了影响微型构造精度的主要因素、微型构造研究的方法及合理工作程序.以河流动力学理论等为依据,以孤岛油田中二中区380口井的测井资料及取心资料为基础,总结了研究区馆陶组上段3~5砂层组各小层的微型构造类型及特征,认为微型构造主要与河道侵蚀下切、古地形、差异压实作用等非构造作用因素有关.探讨了微型构造对油井生产及剩余油分布的影响或控制作用.

Site examinations show that the oil-gas distribution is controlled by microstructures instead of large-middle scale structures during the middle-late stage of oil field development. Accordingly, a systematic analysis is made of the main factors affecting the mapping precision of microstructures, methodology and logical working procedures. It shows that the main factors are well deflection, height of well mouth, length of patching cores, and change of well positions. Therefore, associated adjustments must be done before editing structural maps. Based on logging data from 380 wells, the microstructures and their characters are summarized in the central Zhong-2 district of Gudao oil field. The microstructures can be divided into three types, i.e., positive microstructure, negative microstructure, and oblique microstructures. The positive microstructures mainly include microanticlines, micronoses, microhigh. The negative microstructures mainly include microsynclines and microgrooves. The oblique microstructures are mainly composed of micromonoclines. According to the theory of river dynamics, and study of regional geology, microstructures?distribution, its morphology and scale, the authors consider that the microstructures of the area are primarily connected with the nonstructural factors such as corrosion and down-cutting of channels, ancient landforms and differential compaction. Finally the way that microstructures control well productivity and distribution of remnant oil is discussed.