摘要
针对西峰油田长8油层较厚而干层、水层等夹层较多,分层射孔难度大,射孔后实施笼统注水的实际,为明确注水过程中油层、水层、干层吸水的差异性,搞清油层吸水特征,选用30块岩心进行了并联水驱流动实验。研究结果表明,当油、水层渗透率相近岩心低压并联驱替时,早期产出水是水层水,后期产出水既有水层水也有油层水;在油层渗透率大于干层条件下合注水驱时,最早的产出水来自于油层,在干层出水后,产出水仍主要是油层水;在k油=k水>k干条件下合注水驱,最早出现的产出水来自于水层,而不是油层或干层,随着驱替过程的进行,干层水和油层水相继产出;在k油>k水>k干条件下在低压驱至残余油之前,最早的产出水是油层和水层共同产出的,之后干层水才产出。研究结果对于正确认识油层、水层及干层在互层合注条件下油层水淹规律与剩余油分布规律,制定合理开发措施有重要指导意义。
Chang-8reservoir of Xifeng Oilfield is characterized with thick oil formations interbedded with many dry layers and water layers,but it is difficult to perforate individual layers separately and so in reality all layers are perforated all together and commingled water injection.To understand the differences in water injection profiles among the oil layers,water layers and dry layers,30 cores were selected to conduct the parallel commingled waterflood flow experiments.The results show that when the oil and water layers have similar permeability and the waterflood injection pressure is low,water first produced is from the water layer and later from both the water layer and the oil layer.For the commingled waterflood of the oil layer and dry layer,when permeability of the oil layer is larger than that of the dry layer,water first produced is from the oil layer and the majority of the produced water remains to be from the oil layer even after water breaks-through from the dry layer.For the commingled waterflood of the oil/water/dry layers,when koil=kwaterkdry,water first produced is from the water layer and later from the dry layer and the oil layer.When koilkwaterkdryand the injection pressure is low,first produced water comes from both the oil layer and the water layer,and later the dry layer.These results are important for understanding waterflood sweep mechanisms and the remaining oil distribution under the conditions of commingled injection for the oil/water/dry layers,and they can be utilized to guide the development strategy of tight oil reservoirs with interbedded layers.
出处
《地质科技情报》
CAS
CSCD
北大核心
2015年第6期142-146,共5页
Geological Science and Technology Information
基金
国家自然科学基金项目"特低渗透双重介质砂岩微观孔隙结构的定量表征"(41102081)
教育部重点项目"含微裂缝低渗透砂岩储层微观孔隙结构的定量评价"(212172)
陕西省自然科学基础研究计划"超低渗透砂岩微观孔隙结构的多参数定量表征"(2012JQ5003)
关键词
实验研究
致密油层
非油层
干层
吸水差异
长8储层
experimental study
tight oil formation
non-oil formation
dry layer
injection profile
Chang-8 reservoir
