摘要
研究了低渗透油气藏近井区启动压力梯度的存在原因。以安塞油田王窑区致密砂岩储层为例,在对岩心进行渗透率与有效压力实验的基础上,研究了渗透率对有效压力的敏感性、渗透率的大小与有效压力的敏感性关系。研究表明,存在层理缝或微裂缝时,渗透率在低有效压力下变化特别明显,岩心在净围压的重复变化过程中均具有一定的塑性;在低渗透油气藏近井区储集层的岩石形变在矿场上明显存在,这可能是导致近井区启动压力梯度的主要原因,某些开采特征与流动现象可用近井区岩石形变来解释。通过致密储层压力敏感性机理分析,建立了具有启动压力梯度特征的渗流理论模型。
In order to study the influencing factors for the threshold pressure gradient near the wells in the tight oil and gas reservoirs, the reservoir＇s pressure sensitivity is analyzed and the theoretical model of reservoirs near wells is established. It is shown that when the bedding fracture and minor-fractures exist, the permeability under low-effective pressure changes significantly and that cores show certain plasticity in the process of the repeated changes under the net overburden pressure. The impact of minorfractures should also be considered, when conducting water injection exploitation The in-situ case history shows that the model has good creditability and provides a theoretical base for advanced water flooding.
出处
《科技导报》
CAS
CSCD
北大核心
2009年第1期67-70,共4页
Science & Technology Review
关键词
致密油气藏
近井地带
启动压力梯度
渗流实验
tight oil and gas reservoirs
zone near the wellbore
threshold pressure gradient
flow experiment
