蜀南地区寒武系储层测井识别方法研究

威远地区在上试的基础上,多口老井在寒武系发现了工业油气。在对该区域进行重新认识的过程中,通过综合研究新、老井的资料发现:其储层岩性主要是白云岩,油气运移的主要通道是裂缝。老井的储层识别主要是结合录井和钻井资料,主要根据测井资料的自然电位负异常,电阻率相对低值判断为储层;新井由于资料较多,对产气层做了自然伽马与补偿声波的分布直方图,确定储层的相对GR与AC范围。主要采用成像资料来寻找裂缝,阵列声波能量有衰减、纵横波时差比减小、还有电阻率有尖刀状的降低就可以认为是储层。GR-AC交会图和重叠法对高自然伽马储层识别效果好。

WELL LOGGING IDENTIFICATION METHOD FOR THE RESERVOIR IN CAMBRIAN SYSTEM OF SOUTH SICHUAN

Industry oil or gas has been found in many mature wells in Cambrian system in Weiyuan area.Through synthetic study of new and mature well data,it is found that the reservoir lithology is mainly dolomite and oil-gas migratory pathway is primary fracture.Old reservoir identifi- cation is based on the logging and drilling data.It can be judged as a reservoir according to negative anomaly of spontaneous potential well logging data,relatively low value of resistivity.Because of many data for new wells,a histogram of spontaneous gamma and compensated a- coustic distribution for the gas productive zone can be drawn to determine the relative range of GR and AC.Imaging data can be used to i- dentify fractures.When array acoustic energy has attenuation,time difference ratio of longitudinal wave and transverse wave reduces,and resistivity has sharp reduction,it can be regarded as reservoir.GR-AC cross-plot and overlap method have good result in identifying reser- voirs with high spontaneous gamma.