摘要
中—高含水期低渗透储层经过长期注水开发容易形成优势渗流通道,造成注入水无效循环加剧,严重影响油藏注水开发的效果。以温米油田温西一区块三间房组低孔、中—低渗透储层为例,基于岩性、沉积及微观特征分析优势渗流通道形成的控制因素,综合动、静态资料确定识别优势渗流通道的方法及评价标准,并优选动、静态参数建立综合评价指数模型。研究结果表明,温西一区块三间房组优势渗流通道的形成受岩性、沉积相及微观特征控制;其静态特征表现为岩性粗、物性好,沉积于水下分流河道的主流线上;动态特征表现为吸水剖面存在差异,油井含水率突然升高,示踪剂水线推进快,突破厚度小。研究区优势渗流通道的识别标准为:层内渗透率大于或等于40×10-3μm2,层内渗透率级差大于或等于20,孔喉半径大于或等于3.6μm,月含水率上升率大于或等于30%,单层吸水率大于或等于50%。
Dominant flow path tends to be formed in the low permeability reservoir after long term waterflooding in mediumhigh water cut period,which results in invalid water circulation and severe impact on the water flooding result. Low-porosity and medium-low permeability reservoirs in the Sanjianfang Formation of Wenxi1 block in Wenmi oilfield were taken as examples. Controlling factors of the formation of the dominant flow path were analyzed according to lithology,deposition and microscopic characteristics. An approach to identify the dominant flow path was proposed by use of dynamic and static data and standards suitable for the study area were given. A comprehensive evaluation index model was built up through optimizing dynamic and static parameters. The results suggest that the formation of the dominant flow path in the Sanjianfang Formation of Wenxi1 block is controlled by the lithology,sedimentary facies and microscopic characteristics. The static characteristics are concluded as coarse lithology,good physical property and deposited on the main stream line of underwater distributary channel. The dynamic characteristics include the difference of water injection profile,the sudden rise of water cut in production wells and the rapid flow and breakthrough of tracer material with thin layer. The judging criteria are as follows:permeability is larger than or equal to 40×10-3μm2;permeability ratio is larger than or equal to 20;pore and pore throat radius is larger than or equal to 3.6 μm;monthly increase of water cut is larger than or equal to 30%;water absorption in single layer is larger than or equal to 50%.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2015年第6期74-79,共6页
Petroleum Geology and Recovery Efficiency
基金
中国石油科技重大专项"低渗透油藏有效开发关键技术"(2011B-1205)
关键词
低渗透优势
渗流通道
识别方法
综合评价指数
温西-区块
low permeability
dominant flow path
identification methods
comprehensive evaluation index
Wenxi1 block
