论文部分内容阅读
由于低阻油气层电阻率和水层电阻率接近,给应用常规测井资料识别低阻油气层油水层、确定油水界面位置带来了困难。对低阻层和非低阻层样品进行的完全含水电导率(Co)和溶液电导率(Cw)关系的实验证实,在低阻层由于粘土矿物附加导电作用是形成吉拉克地区三叠系第二油组低阻的主要原因。研究表明,该类低电阻油层被钻穿后,粘土表面阴离子将吸附溶液中的阳离子,被吸附到粘土矿物表面的阳离子又会进一步牵制溶液中阴离子的迁移,使低阻油气层内出现离子滞留现象,形成电荷屏蔽。造成低阻油气层段自然电位测井曲线与非低阻层相比,负差异下降,通过建立一条非低阻状态下的拟自然电位曲线SPrt,将其与SP曲线进行对比,根据叠合特征可识别低阻油气层。实际资料应用表明,该方法在吉拉克地区应用效果明显,能较好地识别低电阻油气层。
Due to the resistivity of the low resistivity oil and gas layers and the resistivity of the aquifer are close, it is difficult to identify the oil and gas reservoirs of the low resistivity reservoirs by using the conventional well logging data and determine the position of the oil-water interface. Experiments on the relationship between complete water conductivity (Co) and solution conductivity (Cw) for low-resistivity and non-low resistivity samples confirmed that the addition of conductive clay minerals to the low resistivity layer resulted in the formation of Triassic The main reason for the low resistance of the two oil group. The results show that the anion in the clay surface will adsorb the cations in the solution after being drilled through the low resistivity oil layer. The cations adsorbed on the surface of the clay minerals will further restrict the migration of anions in the solution, resulting in the occurrence of ion retention Phenomenon, the formation of charge shielding. As a result, the natural potential well logging curve of low resistivity oil and gas reservoir interval has a negative difference compared with that of non-low resistivity layer. By comparing with the SP curve by establishing a quasi-natural potential curve SPrt in non-low resistance state, Can identify low resistivity reservoir. The application of actual data shows that this method has obvious application effect in Jilak region and can well identify the low resistivity oil and gas layers.