GS油田E13油藏水淹层PNN测井响应特征与评价分析

GS油田E■油藏水淹程度严重,已处于中高含水期,平均含水高达77.97%.由于注水开发过程中,先注入淡水后注入污水导致注入水变化性质复杂,致使储集层水淹后地下流体性质、岩石物理性质等发生复杂变化,导致测井响应变化复杂,通过常规的测井技术与解释方法难以精确解释水淹层.为了能精确划分GS E■油田水淹级别,本文结合PNN测井技术,以宏观俘获截面、电阻率曲线和GRPNN的变化定性识别水淹层,当油层被水淹后,GRPNN曲线多呈现异常增大现象,与GR曲线变化出现差异,宏观俘获截面曲线值随着水淹程度的增加而增加.利用宏观俘获截面计算含水饱和度,通过岩石物理实验得出孔隙度、渗透率等参数计算产水率,通过建立产水率和含水饱和度的计算模型定量判断水淹级别,建立了一套适用于GS油田E■油藏的水淹层划分标准.与实际生产吻合,有很好的应用效果,为GS油田E■油藏水淹层划分提供了新的标准.

PNN logging response characteristics and evaluation analysis in E13 reservoir of GS oilfield

The E13 reservoir of GS oilfield is in the middle and high water cut stage,with an average water cut of 77.97%.In the process of waterflood development,the injection of fresh water first and then sewage leads to the complex nature of injected water,resulting in the complex changes of underground fluid properties and petrophysical properties after reservoir waterlogging,which leads to the complex changes of logging response.Therefore,it is difficult to accurately explain the watered-out layer by conventional logging techniques and interpretation methods.In order to accurately dividing GS E13 oilfield water level,based on the PNN logging technology,with macroscopic capture cross section,the change of resistivity curve and GRPNN qualitative identification of water flooded layer,when the reservoir is flooded after GRPNN curve more appear abnormal phenomenon,and the GR curve appeared difference,macroscopic capture cross section curve values increased with the increase of watered-out extent increase.Macroscopic capture cross section is used to calculate water saturation,through the rock physics experiment parameters such as porosity,permeability calculation,through the establishment of water production rate and the water saturation calculation model of quantitative judgment water level,set up a set of suitable for the E13 reservoir of GS oilfield water flooded layer division standard.It is consistent with the actual production and has a good application effect,which provides a new standard for the water-flooded layer division of the E13 reservoir of GS oilfield reservoir.