南堡凹陷奥陶系潜山岩溶塌陷体识别、储层特征及油气勘探前景  

Identification,reservoir characteristics and hydrocarbon exploration prospect of karstic collapsed systems of Ordovician buried hills in Nanpu sag,Bohai Bay Basin

作　　者：王拥军[1,2] 张宝民[1] 董月霞[2] 刘国勇[2] 付卓文[3] 单秀琴[1] 张静[1] 刘静江[1] 

机构地区：[1]中国石油勘探开发研究院,北京10083 [2]中国石油冀东油田公司,河北唐山063000 [3]中国矿业大学,北京100083

出　　处：《石油学报》2012年第4期570-580,共11页Acta Petrolei Sinica

基　　金：中国石油勘探开发研究院中青年创新基金(2010-B-16-03);中国石油冀东油田公司项目(2010-JS-94)资助

摘　　要：渤海湾盆地南堡油田发现井——老堡南1井测试获700 m3/d高产工业油流,标志着南堡凹陷奥陶系潜山勘探获得重大突破,截至2011年底,已累计产油18.62×104 m3、气6 175.35×104 m3。综合研究表明,南堡凹陷奥陶系潜山有利储集体是受多期构造-岩溶作用控制形成的岩溶塌陷体,其识别标志主要表现为:①钻井仅有泥浆漏失、钻速加快而无放空;②岩心上表现为与通常的岩溶洞穴相似的地质特征;③常规测井上表现为高伽马-低电阻(砂、泥充填)或高伽马-高电阻(方解石充填),成像测井上以发育各种洞穴角砾岩为主要特征;④地震剖面上无"串珠状"(俗称"羊肉串")反射,表现为同相轴不连续甚至杂乱、弱振幅反射;⑤与通常的洞穴型储层相比,洞穴通道空间消失,但储集体体积增大,有效储集空间主要是由洞穴溶积砂岩基质孔、溶蚀孔洞、洞穴角砾间残存空隙和裂缝、溶缝组成的复合系统。其形成演化经历了晚加里东—早海西、印支—燕山和喜马拉雅3期构造-岩溶作用及其叠加。岩溶塌陷体广泛发育于南堡凹陷乃至渤海湾盆地寒武系—奥陶系灰岩分布区,油气源充足,具有广阔勘探前景。Well Laopunan 1 , a discovery well for Nanpu oilfied in Bohai Bay Basin, recorded a prolific commercial oil flow of 700 m3/ d in 2004, which marks a significant breakthrough in exploration of Ordovician buried hills in Nanpu sag, Bohai Bay Basin. Up to the end of 2011, the cumulative oil production of the well has been 18.62×104m3 for oil and 6 175.35×104m3 for gas. The present pa per discussed reservoir characteristics and controlling factors of Ordovician buried hills in Nanpu oilfield based on core drilling, seis mic and logging data. This comprehensive study indicates that Ordovician buried hills in Nanpu sag are mainly karstic collapsed sys tems controlled by polycyclic tectonic movements and multiphase karstification. The recognition of these karstic collapsed systems is basically characterized by the following aspects：（1）there is only a mud leakage without blowdown as drilling speed accelerates; （2） cores have geological features similar to a common karstic cave; （3）the conventional logging shows high gamma and low resistance features for sand and mud filling or high-gamma and high-resistance features for calcite filling, and the imaging logging displays vari ous developed cave breccia features;（4）seismic profiles show no ＂beaded＂ reflection （commonly known as a ＂lamb-bunch＂ reflec tion）, displaying a discontinuous or even chaotic and weak-amplitude reflection in event; and （5）compared with a common cave, the res- ervoir cave passage space disappears while reservoir volume increases,in which the effective reservoir space of karstic collapsed systems is a composite pore system composed mainly by matrix pores of cave katatectic sandstones, vugular-solution void, and residual pores, fissures and dissolved fractures between cave breccias. The formation and evolution of this pore system have experienced three episodes of tectonic activity and karstification during the Late Caledonian-Early Hercynian, Indosinian-Yanshan and Himalaya periods. The re search shows that karstie co

关 键 词：岩溶塌陷体 识别标志 储层特征 溶蚀机理 碳酸盐岩 南堡凹陷 渤海湾盆地 

分 类 号：TE112.221[石油与天然气工程—油气勘探]