缝洞型油藏单井注氮气见效特征

Study on the effective characteristics of single-well nitrogen injection in Fracture-Vug reservoir

为了开采"洞顶阁楼油",塔河油田开展了单井注氮气矿场试验,并取得了较好的效果。但单井注氮气增油效果差异很大,影响了现场单井注气的大规模应用。通过综合分析,认识到岩溶成因和储集空间类型是决定单井注氮气效果的基础;基于岩溶成因及储集空间类型,将注气井划分为4种类型,从产油量、有效期、含水、压力等4个指标对比分析了不同类型井注气后的见效特征,可对矿场注气选井提出建议,指导矿场注气试验的实践和推广。

To exploit the remaining oil in the high position of the reservoir,field test of nitrogen injection in single well has been carried out in Tahe Oilfield and good results have been achieved.However,the effect of nitrogen injection in single well is quite different,which has affected the large scale application of gas injection in field.Through comprehensive analysis,it is recognized that the karst genesis and the type of reservoir space are the basis for determining the effect of nitrogen injection in a single well.Based on Karst genesis and reservoir space type,gas injection wells are divided into four types.By contrast from oil production,period of validity,water content and pressure,the effective characteristics of different types of wells after gas injection are compared and analyzed.According to these characteristics,some suggestions for field gas injection well selection are put forward,which can guide the practice and popularization of field gas injection test.