碳氢比测井应用效果分析

Applications of Carbon-hydrogen Fluid Saturation Log in Tuha Oilfield

碳氢比测井是FCH地层流体饱和度测井的简称。吐哈油田既有低孔隙度、低渗透率 ,又有高孔隙度和中高渗透率储层 ,且矿化度多变 ,储层多样且复杂 ,存在有高电阻率水层、低电阻率油层。对于如何认识剩余油分布、评价油层水淹程度及边底水动态 ;在新井射孔前能否评价油水层分布状况等难题 ,碳氢比测井可以根据快中子在地层中产生核反应过程中的非弹性散射、弹性散射、俘获反应及核反应整体效应理论 ,依据探测到的碳氢元素的丰度计算出地层介质内的碳氢比值 ,进而求取地层中的含油或剩余油饱和度 ,其方法应用减少了孔隙度和矿化度的影响。通过实例分析了该技术在吐哈油田不同类型储层中的适应性。

C/H log is short for FCH formation fluid Saturation log.In Tuha Oilfield there are many diverse reservoirs with low and high porosities, low and middle-high permeabilities and variable salinities.In addition, its water bed resistivity is lower and oil bed resistivity higher. Log examples of three different reservoirs indicated that C/H logging technology is adaptable to various sandshale reservoirs in Tuha Oilfield.Clear C/H curves and oil-water interfaces helped us to effectively evaluate oil-bearing or remaining oil saturation of reservoirs and producing zones, waterflooded degrees and edge & bottom water status.C/H log data may provide us with more reliable perforating intervals before new well production. Because the abundance of carbon, hydrogen and chlorine in formation fluid and C/H-based oil-bearing saturation are the basic evaluation standards, effects of porosity and salinity have been reduced obviously. On the basis of effect velocity theory of nuclear reaction and combination of identifying oil, water or waterflooded zone and dry bed with chart characteristics, we are able to visualize the hydrocarbon-bearings, physical properties, fluid volumes and marginal water production rate, etc.