基于灰色理论指导的储层构型半定量表征及优质储层预测——以西湖凹陷A构造花港组H3砂层组为例  

Semi-quantitative study on reservoir configuration in grey theory——A case study of H3 sand unit of Huagang Formation in A Structure, Xihu Sag

作　　者：姜雪 熊志武 JIANG Xue;XIONG Zhiwu(CNOOC China Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《海洋地质与第四纪地质》2022年第6期162-172,共11页Marine Geology & Quaternary Geology

基　　金：“十三五”国家重大专项“东海深层大型气田勘探评价技术”(2016ZX05027-002),“西湖凹陷西部地区勘探开发关键技术研究”(CNOOC-KJ135ZDXM39SH01)。

摘　　要：A构造位于西湖凹陷中北部,花港组H3砂层组为主力目的层,其储层横向分布相对稳定,但储层砂体厚度大,非均质性强,骨架河道的雕刻不清制约了优质储层的预测。利用灰色理论,定量计算西湖凹陷A构造花港组隔夹层综合评价指标IRE,识别厚层砂岩中的隔夹层类型,划分河道期次,识别骨架河道。此外,计算河道宽厚比和砂地比,半定量表征河道连通性及展布特征,预测优质储层发育区。结果表明,西湖凹陷A构造花港组发育两种类型隔夹层:落淤层夹层和泥岩层隔层,其中落淤层IRE值为24~45,泥岩层IRE值为51~110,在H3砂层组识别出3大套共10期单河道砂体。工区单河道宽厚比为38.87,折算出各期河道展布范围为1.1~2.3 km,河道砂体几乎都呈叠拼式展布。在地震复合微相指导下,对花港组早期河道进行识别和追踪,结合沉积微相、粗粒相带及成岩相分布特征,认为A构造南部有利储层更为发育。Using grey theory, we calculated quantitatively the comprehensive evaluation index IRE of the interlayer in Huagang Formation(Fm)of the A Structure in the Xihu Sag, China Sea, from which the type of interlayer in thick-bedded sandstone was identified and the channel period was divided. Combing logging data and lithofacies associations, we clarified the strength of hydrodynamic force, divided the reservoir types,and then defined influencing factors of high-quality reservoir development. In addition, based on single channel identification and classification,the average thickness of single interlaced strata was determined, and the river width-thickness ratio and sand-soil ratio were calculated to semiquantitatively characterize the river connectivity and distribution characteristics. Based on the influencing factors and channel distribution characteristics of high-quality reservoirs, the development area of high-quality reservoirs was predicted. Results show that there are two types of interlayers in Huagang Fm of the A Structure, namely, desilting stratum and mudstone interlayer. The desilting stratum with low IRE was 24~45, and that of the mudstone layer was 51~110, much greater, thus the three sets of single channel sand bodies in 10 stages were identified in the H3 sand unit of Huagang Fm. The width-thickness ratio of single channel in the work area was 38.87, and the range of channel distribution in each period was calculated to be 1.1~2.3 km. The channel sand bodies are almost overlapped. Under the guidance of seismic composite microfacies, the early channel of Huagang Fm was identified and tracked. Combined with the distribution characteristics of sedimentary microfacies, coarse-grained facies zoning, and diagenesis development, we considered that the favorable reservoirs are more developed in the south area of the A Structure.

关 键 词：灰色理论 隔夹层 储层构型 优质储层 

分 类 号：P744[天文地球—海洋科学]