SU气田低电阻率气层的成因及测井解释技术

SU气田砂岩低电阻率气层形成原因复杂,气水层识别也非常困难.利用测井、地质及试气等资料,对低电阻率气层的成因及特点进行了分析,确定低电阻率气层的形成主要是由低缓的构造形态、砂岩非均质性、储集层微观结构、高束缚水饱和度、泥浆侵入及粘土膜滞水增厚引起的.在此基础上通过具体实例提出了纵波差值法、声波气检测、核磁共振测井和阵列式电阻率反演识别低电阻率气层解释技术,见到了明显的地质效果,提高了测井解释精度.

Geneses of Low Resistivity Gas Zone and Its Log Interpretation Technology in SU Gas Field

Since the geneses of low resistivity gas zone with sandstones are complex in SU gas field, it is difficult to indentify the gas zone and water zone. Log, geology and gas testing data are used for analysing the geneses and characters of low resistivity gas zones. It is confirmed that main causes resulting in low resistivity gas zones are the low and flat geologic structures, heterogeneity of sandstone, microscopic texture of reservoir, high bound water saturation, mud invasion and water increment on the clay membranes. Based on the above analysis, some interpretation methods such as compressional wave slowness acoustic gas detection, NMR logging and array resistivity inversion, are bought up to indentify low resistivity gas zones which provides us visible geologic results and improves the interpretation accuracy.