低阻油层判别技术在吉林油区的应用

Application of identification technique for low resistivity reservoir in Jilin Oilfield

吉林油区低阻油层判别技术能够有效识别因储层的泥质含量高、砂泥薄互层、钻井液侵入、地层水矿化度异常高等因素造成的低阻油层,提高了油水层解释精度,解决了油田开发的关键问题。针对不同的影响因素,采用孔隙度—电阻率改进电性图版识别法,用"纯砂岩"地层的电阻率值做电性图版来识别孔隙流体性质在四方坨子地区取得较好的效果;利用束缚水饱和度—含水饱和度交会图分析法,求取地层含水饱和度Sw和地层束缚水饱和度Swi来判别地层产油或产水,发现了大老爷府大型整装低阻油田;通过分析在淡水钻井液侵入条件下电阻率径向上变化的"无侵线法"油水层识别技术及其应用,发现了一批高产层或油田。

The identification technique for low resistivity reservoir in Jilin Oilfield can effectively be used to recognize low resistivity reservoir resulted from high shale content, thin interbedded sandstone and mudstone, drill fluid invasion and abnormal high formation water salinity. Identification accuracy for oil and water layers is improved and the oilfield development problems are settled by this technique. Different identification techniques are used based on different reservoir conditions. Improved porosity-resistivity electric chart is used for identification. Resistivity value of clean sandstone is used as the electric chart to recognize the pore-fluid quality, and the better result is gained in Sifangtuozi area. Water saturation （Sw） and irreducible water saturation （Swi） derived from their crossplot is used to recognize oil or water layer, Dalaoyefu large low resistivity reservoir is found by this method. Identification accuracy for oil and water layers is greatly improved by applying ＂Non-Invasive Line Method＂ with vertical resistivity changes under invasion of fresh water drill fluid. Some layers or oilfields with high production are found by this method and other assistant identification techniques.