辽河西部凹陷杜84块兴隆台Ⅰ油层隔夹层识别、成因及分布特征

摘要

隔夹层是储层非均质性的主要控制因素之一,探讨隔夹层为油藏精细描述和剩余油研究奠定基础.以岩心、生产动态数据为基础,综合辽河西部凹陷曙一区1735口测井资料,利用电性及物性测试分析,按照岩心标定测井曲线,编制5种参数(声波时差、深侧向电阻率、感应电导率、孔隙度和渗透率)交会图.将研究区的隔夹层分为泥质隔夹层和物性隔夹层两类,并建立两类隔夹层定量划分标准和识别模板.研究区隔夹层发育主要受控于洪泛期沉积、局部区域水动力减弱、多期河道切割侵蚀、前积(侧积)和河床滞留沉积的综合作用.泥质隔夹层主要集中分布在滨浅湖和分流间湾处,物性隔夹层主要分布在水下分流河道分支处及分流间湾的局部;在靠近物源区,隔夹层分布较少且较孤立,仅在两期河道叠置间发育,而在远离物源区分布明显增多且厚度增大;隔夹层在垂向上的分布与所处的基准面旋回关系密切,在中期旋回上升半旋回的3个阶段,隔夹层自下而上数量增多、厚度增大.最后提出隔夹层的岩性、物性、厚度及展布特征影响蒸汽辅助重力泄油(SAGD)技术对辽河油田稠油的生产.%Barriers/baffles in reservoirs have been considered as one of the control factors of reservoir heterogeneity.A study on barriers/baffles may provide a sound foundation for a fine characterization of reservoirs and a more accurate prediction of remaining oil distribution.By combining core observation and dynamic production data as well as logging data of 1 735 wells in the Shuyi Block in western Liaohe depression,we drew cross plots of five parameter (i.e.interval transit time,lateral resistivity,induction conductivity,porosity and permeability) in accordance with core calibrated logging curves,and analysis result of electrical and physical property tests.We classified the barriers/baffles into two types (shaly barriers/baffles and physical barriers/baffles) and established a standard and a template for their quantitatively identification.The barriers/baffles developed in the study area were mainly controlled by factors including sedimentation of flooding stage,weakening local hydrodynamics,multi-stage fluvial erosion cuttings,progradation and riverbed lag deposition.The shally barriers/baffles were mainly distributed in shallow lakes and interdistributary bays,while the physical barriers/baffles were mostly located in bifurcations of underwater channels and local areas of interdistributary bays.Barriers/baffles were scarce and isolated in the stacked channels near provenance.However,they were more frequent and thicker away from provenance.Their vertical distribution was closely related with the base level cycles and their number and thickness got larger from bottom up in the ascending semi-cycles of the middle-long term base level cycles.We also proposed that the lithology,physical properties,thickness and distribution of barriers/baffles had certain effects upon the performance of SAGD (steam-assisted gravity drainage) in heavy oil discovery of Liaohe Oilfield.