基于河型演变模式的单一成因砂体对比研究  

A comparative study of sand body genetic types based on model of fluvial evolution

作　　者：束青林[1] 肖斐[2] 丛国林[1] 

机构地区：[1]中国石化胜利油田分公司,山东东营257001 [2]胜利油田森诺胜利工程有限公司,山东东营257000

出　　处：《油气地质与采收率》2014年第4期16-18,112,共3页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"胜利油田特高含水期提高采收率技术"(2011ZX05011);中国石化重大提高采收率先导试验项目"孤岛油田中一区Ng3聚合物驱后井网调整非均相复合驱先导试验"

摘　　要：通常对河流相河型和单一成因砂体的研究,主要依据粒度分布、砂体形态和沉积构造等特征要素,但通过研究观测现代河流沉积,发现在河流层序演化的过渡阶段,不仅河道形式会呈现不同变化,而且也影响不同成因砂体交互出现。为此,在孤岛油田中一区油井井间距和水井井间距为75 m、注采井距为150 m的密井网条件下,开展了利用河型演变模式指导曲流河、辫状河单一成因砂体对比和拼接的研究。通过建立辫状河—曲流河、曲流河—辫状河、辫状河—网状河、网状河—辫状河、网状河—曲流河和曲流河—网状河6种河型纵向叠置演变模式,确认Ng1+2砂层组为网状河沉积;通过建立标志层附近等高程对比、河道叠置砂体细分对比、河道砂体下切对比和侧向相变对比4种地层对比模式,开展单一成因砂体识别;结合矿场注采对应关系,建立了单一河道内部、河道—河道、河道—废弃河道—河道和河道—溢岸—河道4种成因砂体拼接类型,注采连通性因成因砂体拼接关系不同而存在差异,这种连通性差异主要控制特高含水期层内剩余油差异富集,据此通过指导井网调整流场转向,从而进一步提高水驱、化学驱采收率。Usually,the study of fluvial river type and the single genetic sand body is mainly on the analyses of particle size distribution,sand body shape,sedimentary tectonics and so on.Observations on modern channel deposits show that at the transition stage of sequence evolution,not only the channel form changes,but also sands of different genetic types present alternately.Under the condition of dense well pattern with oil well spacing 75 m,injection well spacing 75 m,and injector-producer spacing 150 m in one block of Gudao oilfield,study was carried out to identify and compare sand body genetic type of meandering river and braided river by using the evolution mode of river regime.Ng1+2 sand formation is proved as braided stream sedimentary by establishing 6 kinds of vertically stacked evolution model of river regime,including braided stream-meandering river,meandering river-braided river,braided riverbraided stream,braided stream-braided river,braided stream-meandering and meandering river-braided stream.Four kinds of stratigraphic correlation modes were proposed to identify single sand body,which are vertical comparison near marker bed,superimposed channel sand body contrast,channel sand body incised comparison and lateral phase comparison.Four types of sand body amalgamations were established combined with field injection-production relation which include single channel internal,channel-channel,channel-abandoned channel,and channel-overbank-channel.Differences exist in injection-production connectivity owing to the differences in sand body amalgamations.The differences of connectivity mainly control differential accumulations of remaining oil at the extra high water-cut stage,and guide well pattern adjustment to improve the water flooding as well as chemical flooding recovery efficiency.

关 键 词：河型演变 单一成因砂体 河流层序演化 特高含水期 剩余油分布 

分 类 号：TE111.1[石油与天然气工程—油气勘探]