元坝长兴组气藏礁滩沉积微相地质特征及测井识别

摘要

The main developmental phases in Changxing formation of Yuanba gas reservoirs are reef and bioclastic shoal reservoir,controlled by different phase with the degree of reservoir development,logging data to carry out the identification of the characteristics of the reef insider is essential.Full electrical imaging and conventional logging data,a detailed description of the environment for the growth,morphology and rock structure characteristic differences in the logging response characteristics of different reef and non-reef strata,discusses Beach nuclear Beach edge and interbank logging response characteristics.Comprehensive studies have shown Changxing gas reservoir reef facies sedimentary cover the reef base-reef nuclear-reef to reef core-reef cover mode,the total development of the two reef cap reservoir vertical performance,its high-quality reservoir is mainly concentrated in the reef cover.Beach nuclear edge interbank Beach logging response characteristics biggest difference is that in the low-energy depositional environment interbank GR higher (30～80 API),was the type and spike-shaped,while the Beach nuclear and beach edge in high-energy andhigher energy depositional environment,GR is low (less than 20 API).In addition,Beach nuclear Beach margin,the biggest difference is that the Beach nuclear RD was "Out of round oversized type" electrical imaging visible cross-bedding,solution porosity development,beach edge was "jagged" RD low angle bedding,clip a small amount of dissolutionthin layers.The beach body widely distributed,but high-quality reservoir is mainly concentrated in nuclear Beach,the Tanjianshan almost not developed reservoir.Established on the basis of the integrated core,well logging,seismic data and regional geological background gas yuanba Tian Changxing group of reef (reef cap,reef core,reef base) and bioclastic beach (beach nuclear,beach edge,Tanjianshan) logging identification mode.%元坝气田长兴组气藏主要发育生物礁相和生屑滩相储层.生物礁与非生物礁地层由于生长环境、形态及岩石结构特征差异,测井响应特征不同.利用电成像和常规测井资料,对这些特征差异进行了详细描述,论述了滩核、滩缘和滩间的测井响应特征.长兴组气藏礁相地层沉积模式纵向上表现为礁基—礁核—礁盖—礁核—礁盖,共发育2期礁盖储层,优质储层主要集中在礁盖.滩核、滩缘与滩间测井响应特征的区别在于滩间处于低能沉积环境,自然伽马较高(30～80 API之间)、呈指型和尖峰状,滩核和滩缘处于高能和较高能沉积环境,自然伽马为低值(小于20 API);滩核与滩缘区别在于滩核电阻率呈隆起状、电成像可见交错层理、溶蚀孔洞发育,滩缘电阻率呈锯齿状,为低角度层理,夹少量溶蚀薄层.滩体分布广泛,但优质储层主要集中在滩核,滩间几乎不发育储层.整合岩心、测井、地震资料和区域地质背景,建立了元坝气田长兴组生物礁及生屑滩的测井识别模式.