摘要
近年来,苏北盆地火山岩油藏勘探取得一系列成果,但针对火山岩分布、岩相及油藏成藏特征研究较少。本文在井震结合的基础上,充分应用岩心、薄片、物性分析等资料,尝试系统研究溱潼凹陷火山岩岩相模式,总结油藏类型,分析勘探潜力。溱潼凹陷火山岩沿深大断裂呈中心式喷发,喷发期次单一,主要形成于渐新世三垛运动期,主要发育火山通道相和溢流相。火山通道相的次火山岩亚相和隐爆角砾岩亚相主要分布在阜二段—戴南组,其中次火山岩亚相分布最为广泛;溢流相的玄武岩主要分布在垛一段顶部,是一套区域性标志层。溱潼凹陷新生代火山岩油藏主要发育3种类型:隐爆角砾岩型、接触蚀变型、侧向遮挡型,并建立了5种火山岩油藏成藏模式。火山岩油藏富集受火山岩形成时间、规模、岩性等因素影响。火山作用既能催熟烃源岩,又有利于砂岩储层形成裂缝,溱潼凹陷火山活动主要对油气成藏起促进作用。未震穿阜四段泥岩的隐爆角砾岩体具有更有利的成藏组合。针对不同类型火山岩油藏勘探均取得一定成果。在茅山—帅垛—储家楼地区共发育12个火山口,118km2侵入岩,预计3种类型火山岩油藏资源量1500×104 t,是溱潼凹陷重要的资源接替领域。
Volcanic rocks are widespread in Subei basin, recently industrial oil run is obtained in basalt of Jinghu depression, diabase of Gaoyou depression and volcanic vent of Qintong depression. Based on logging information and seismic material, combined with core, slice and physical property analysis, the accumulation characteristics and exploration potential of volcanic reservoir of Qintong depression were studied. The results indicated that： volcanic rocks present central type eruption along with deep fracture, which were formed in Sanduo Movement of Oligocene, volcanic vent facies and overflow facies were developed. Subvolcanic rock subfacies and cryptoexplosive breccia subfacies that belong to volcanic vent facies are distributed among Ef2-Edl, while subvolcanic rock subfacies are more widespread. Basalts that belong to overflow facies were distributed on the top of Es1, which was a marker bed that used for stratigraphic correlation. Cryptoexplosive breccia type, contact alteration and lateral barrier type reservoir were developed in Cenozoic strata, meanwhile five accumulation models were built up. Accumulation of volcanic res- ervoir is controlled by development time, scale and lithology. Volcanism is not only benefit acceleration of source rock maturation, but also avail the formation of crack for sandstone, therefore volcanism play a driving role in hydrocarbon accumulation. Cryptoexplosive breccia bodies that did not break mudstones of Ef4 possess more favorable reservoir formation combination. Certain effects were obtained in the exploration of different volcanic reservoir. 12 volcanic vent and 160 square kilometers intrusive rock were developed in Maoshen-Shuaiduo-Chujialou region, estimated resources about 1500×10^4t are important for reservoir exploration of Qintong depression.
出处
《非常规油气》
2017年第5期1-9,共9页
Unconventional Oil & Gas
基金
中国石化科技项目"华东探区阜宁组致密油区带评价与目标优选"(P14007)资助
关键词
溱潼凹陷
火山岩油藏
隐爆角砾岩亚相
板岩
Qintong depression
volcanic reservoir
cryptoexplosive breccia subfacies
slate
