准噶尔盆地西北缘风城组白云岩成因及油气富集因素.pdf

石油劫探与开发
2011年12月
PETROLEUM EXPLORATION AND DEVELOPMENT
ol.38No.6685
文章编号:100047(2011)06-0685-08
准噶尔盆地西北錄风城组白云岩成因及油气富集因素
冯有良,张义杰,王瑞菊,张光亚,吴卫安
(中国石油勘探开发研究院
基金项目:准噶尔盆地西北缘新层系新区带综合评价与目标优选(2009-9705-01)
摘要:利用钻井、岩心、地震、测井及地球化学资料,分析准噶尔盆地西北缘二叠系风城组白云岩沉积环境、成因、
分布规律及白云岩储集层油气富集高产因素。风城组白云岩按产状和沉积构造可分为纹层状泥质白云岩、薄层状白
云岩和斑状白云岩,主要为准同生白云岩和后生白云石化白云岩。准同生白云岩形成于半深湖成水环境;后生白云
石化白云岩是发育在半深湖咸水环境下的碳酸盐岩灰泥在成岩期经后生白云石化作用形成。白云岩主要分布在火山
喷发或逆冲断裂活动形成的古地貌斜坡上。白云岩储集层的储集空主要为溶蚀孔隙和裂隙。白云岩储集层富集高
产的控制因素是裂缝及构造背景。图8表3参20
关键词:白云岩;油气富集;沉积环境;风城组;准噶尔盆地西北缘
中图分类号:P581;TE121文献标识码:A
Dolomites genesis and hydrocarbon enrichment of the Fengcheng Formation
in the northwestern margin of Junggar Basin
Feng Youliang, Zhang Yijie, Wang Ruiju, Zhang Guangya, Wu Wei'an
(Petro China Research Institute of Petroleum Exploration Development, Beijing 100083, China)
Abstract: Using the data of cores, well logging interpretations, seismic sections and experimental geochemistry, this paper analyzes the
sedimentary environment, genesis, and distribution of dolomites, as well as the hydrocarbon enrichment factors of dolomite reservoirs in
the Permian Fengcheng Formation. According to attitude and structure, the dolomites of the Fengcheng Formation are divided into lamina
dolomites, thin-bed dolomites and spotted dolomites. They are mainly the penecontemporaneous and epigenetic dolomites, the former
was deposited in a saline semi-dee lake, while the latter results rom the dolomitization of lime mud that was deposited in a saline
semi-deep lake during the diagenetic stage. The dolomites are distributed at the palaeoslope formed by volcano eruption and movement
of thrust faults and the main dolomite reservoir spaces arc dissolved pores and fractures. The factors controlling hydrocarbon enrichment
are fractures and structural back ground
Key words: dolomite; hydrocarbon enrichment; sedimentary environment; Fengcheng Formation northwestern margin of Junggar Basin
准噶尔盆地西北缘二叠系风城组是早二叠世前陆风城组从下而上可划分为3段:风一段(P1f1)发育深
盆地构造背景上发育起来的一套湖相沉积组合?。风灰色一灰色泥岩、凝灰质泥岩夹白云质砂岩、白云岩
城组发育了一套白云岩、泥质白云岩、凝灰质白云岩、凝灰质自云岩、泥质白云岩和凝灰岩。风二段(P1f2)
白云质泥岩和自云质砂岩,是良好的油气储集层。本发育白云质砂岩、灰色泥岩夹泥质白云岩。风二段
文基于研究区钻井
地震、测井及地球化学资(PIf3)发育灰绿色泥岩、泥质白云岩与砂岩、砂砾岩
料,对准噶尔盆地西北缘风城组白云岩储集层的沉积构成的向上变粗的旋回(见图2)。岩石组合特征表明
环境、成因、分布规律及油气富集高产因素进行分析。风城组是一套扇三角洲一深湖沉积体系い,?。
1地质背景
2白云岩的分布
准噶尔盆地西北缘早二叠世前陆盆地可划分为西
利用录井资料统计的风城组各段白云岩、砂砾岩及
南缘的车排子凸起、北东向展布的克百逆断层带及其火山岩的厚度,结合地震枏和地震属性资料及岩石组合
派生的北西向鼻状构造、乌尔禾和夏子街逆断层带及特征,编制风城组各层段沉积相分布图(见图3)。分析表
伴生的背斜构造带、玛湖凹陷?(见图1)。下二叠统明:①风城组白云岩分布首先受陆源碎屑物质输入的制