苏北盆地溱潼凹陷浅成侵入岩接触变质带储层特征及控制因素

Reservoir characteristics and controlling factors in the contact metamorphic zone of hypabyssal intrusive rocks in the Qintong Sag, Northern Jiangsu Basin

吴峻 陈孔全 张锋 沈均均 刘金帅 谭静

WU Jun CHEN Kongquan ZHANG Feng SHEN Junjun LIU Jinshuai TAN Jing

长江大学 非常规油气湖北省协同创新中心, 武汉 430100 2. 中国石化 华东油气分公司, 南京 210019

Hubei Collaborative Innovation Center of Unconventional Oil and Gas, Yangtze University, Wuhan, Hubei 430100, China 2. SINOPEC East China Company, Nanjing, Jiangsu 210019, China

以苏北盆地溱潼凹陷帅垛-茅山地区浅成侵入岩接触变质带为研究对象，综合岩心薄片观察、测井解释和井震结合等方法，研究了侵入岩接触变质带储层的空间分布规律，解剖了典型接触变质带油气藏的储层发育特征，据此，对溱潼凹陷浅层侵入岩接触变质带的储层有利区带进行了预测。研究表明：围岩受侵入岩的影响发生蚀变，形成侵入岩接触变质带储层。接触变质带在测井曲线上表现出高自然伽马、中等声波时差、中等自然电位和高电阻率等特征。接触变质带在垂向上发育在侵入岩上、下两侧，在发育厚度上两者呈正相关关系。接触变质带蚀变泥岩的厚度是影响优质储层分布的主要因素，发育在火山通道附近且厚度较大的接触变质带蚀变泥岩储层是油气成藏的有利区。

Reservoir characteristics and controlling factors in the contact metamorphic zone of hypabyssal intrusive rocks are of a great significance for the exploration and development of magmatic oil reservoirs. The contact metamorphic zone of hypabyssal intrusive rocks was well preserved in the Shuaiduo-Maoshan areas of the Qintong Sag, Northern Jiangsu Basin, and is an ideal area to understand this mechanism. Systematic core and drill cuttings observations, well logging interpretation and borehole-seism-modulus integration techniques were conducted to evaluate spatial distribution regularities and dissect the characteristics of reservoir development in a typical contact metamorphic zone. Some favorable reservoirs in the contact metamorphic zone of intrusive rocks in the Qingtong Sag were predicted. The studies showed that wall rocks were altered by the influence of intrusive rocks, forming the contact metamorphic zone of intrusive rocks. The contact metamorphic zone has the characteristics of high natural gamma, medium sonic time difference, medium natural potential and high resistivity on logging curves. The contact metamorphic zone generally distributed above and below the intrusive rocks, and has a positive correlation with the thickness of intrusive rocks. In addition, the thickness of altered mudstones in the contact metamorphic zone is the main factor affecting the distribution of high quality reservoirs, and the high-quality reservoirs in the contact metamorphic zone near to volcanic sills are favorable for hydrocarbon accumulation.

https://doi.org/10.11781/sysydz201803323