湖相致密白云岩不均一油藏特征及主控因素

发布时间：2018-04-05 00:24

本文选题：泥质白云岩　切入点：致密岩性油藏　出处：《地球科学》2017年12期

【摘要】：渤海湾盆地塘沽地区沙三5亚段发育湖相含油泥质白云岩层系,油藏顶面埋深2 800~3 600m,属于中深-深层的断块-岩性油藏,储层为致密裂缝白云岩.本文通过岩心观察、实验室分析、压力测试、裂缝分析等手段,重点研究了致密白云岩储层岩石相、储集性、复杂含油性和油藏不均一性特征,分析了成藏主控因素及成藏模式.研究表明:储层岩性以白云岩、泥质白云岩为主,为中-低孔、低渗-特低渗的裂缝-孔隙型储层,储集空间主要为晶间孔、溶孔、裂缝及溶缝;超压与含油性密切相关,超压断块井均中高产、含水率低于20%且呈持续降低趋势,常压断块井均低产、含水率高于55%且稳定-上升趋势;白云岩层系内厚层泥岩为优质烃源岩,提供充足油源;断层封闭性控制油气聚集,进而控制生烃型超压的分布,超压成为油气富集的重要标志;油气充注晚于断块-岩性圈闭形成时间,使油气充注有效.
[Abstract]:The lacustrine oil-bearing muddy dolomite system is developed in the sub-member of Sha 35 in Tanggu area, Bohai Bay Basin. The top layer of the reservoir is buried at the depth of 2 800 ~ 3 600 m, which belongs to the middle deep fault block lithologic reservoir and the tight fractured dolomite.By means of core observation, laboratory analysis, pressure test and fracture analysis, the characteristics of rock facies, reservoir, complex oil content and reservoir heterogeneity of tight dolomite reservoir are studied in this paper.The main controlling factors and the model of reservoir formation are analyzed.The results show that the reservoir lithology is dominated by dolomite and argillaceous dolomite, which is a medium-low porosity, low-permeability and ultra-low-permeability fracture-pore reservoir. The reservoir space is mainly intergranular pore, dissolved pore, fracture and dissolved fracture, and the overpressure is closely related to the oil content.The overpressure block wells are of medium and high yield, the water cut is below 20% and shows a continuous decreasing trend, the normal pressure block wells have low production, the water cut is higher than 55% and the trend is stable and upward, the thick mudstone in the dolomite series is a high quality hydrocarbon source rock, which provides sufficient oil source.Fault sealing controls the accumulation of oil and gas, and then controls the distribution of hydrocarbon generating overpressure, which becomes an important indicator of oil and gas enrichment, and oil and gas charging is later than the forming time of fault block lithologic trap, which makes oil and gas charging effective.
【作者单位】：莱斯大学地质系;中国地质大学构造与油气教育部重点实验室;新疆煤田地质局;中国石油大港油田公司第四采油厂;
【基金】：“十三五”国家油气专项“近海大中型油气田形成条件及勘探技术”(No.2016ZX05024-006) 中国石油股份有限公司大港油田重点项目“塘沽地区沙三5特殊岩性体沉积特征及油藏综合评价”(No.DGYT-2012-JS-566)
【分类号】：P618.13

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