与火山作用有关的岩系测井识别与物源分析——以松南十屋油田营城组为例

Logging Identification of Volcano-Related Rocks and Its Application in Provenance Analysis——An Example from the Yingcheng Formation in Shiwu Oilfield in Southern Songliao Basin

松辽盆地十屋油田属于构造-岩性油气藏。营城组发育正常沉积岩、火山熔岩、凝灰岩、沉凝灰岩和凝灰质砂岩,岩石中不同程度地含有火山碎屑物质。火山碎屑的含量,不仅决定了岩石类型,而且影响储层物性。与火山作用有关的岩石类型及其分布反映了物源区的特征。岩心的岩性识别虽然精准,但数量与分布有限,影响到确定物源-沉积体系的类型与分布。测井资料的岩性识别,特别是含有火山碎屑岩石的识别可以弥补取心不足造成的限制。十屋油田不同层位岩石中K元素测井值的对比,相同层位岩石中的U、Th元素测井参数交会图,GR、DEN、CNL、AC、Rt、RMSFL测井参数的玫瑰图和GR-PE、GR-DEN测井参数交会图,对十屋油田营城组Ⅳ-Ⅴ砂组与火山作用有关的岩石实现了有效的岩性识别,形成了测井识别模式。测井识别岩性和岩心识别岩性相结合,确定了研究区5种岩石类型分区,证明了松辽盆地十屋油田营城组Ⅳ-Ⅴ砂组来自火山岩物源、再旋回沉积岩源区的正常碎屑岩物源、受花岗岩影响的正常碎屑岩物源、受花岗岩和火山岩影响的正常碎屑岩物源以及混合区域物源沉积体系的存在与分布范围。

The Shiwu oilfield in Songliao basin is a structural lithological hydrocarbon reservoir. There are some kinds of rocks developed in the Yingcheng Formation in Shiwu oilfield, such as sedimentary rock, lava, tuff,sedimentary tuff and tuffaceous sandstone. Each kind of rocks contains a certain amount of volcanic fragments. The content of volcanic material often determines rock type and makes iower reservoir properties. Types of volcanogenic rocks and their identification reflect the characteristics of the source area. Lithologicalidentification with core is accurate, however, the number and distribution of core and drill is limited, which has made it difficult to determine the types of source sedimentary system and its distribution. Lithology identificationusing logging information,especially forvolcanic clastic rocks, can make up for the lithological identification restrictions caused by inadequate coring. Lithology identification is carried out by comparison of Potassium logging content of rocks in the different layer, the logging parameter crossplot of Uranium,Thorium of rocks in the same layer, the rose diagram of logging curves of GR, DEN, CNL, AC, R, ,RMsF~. and the crossplot diagram of GR-PE, GR -DEN. Lithology identification of volcano-related rocks has been done effectively and the logging recognition pattern has been established in member IV-V of the Yingcheng Formation in Shiwu oilfield. The combination of lithology identification using logging and core has made 5 kinds of rocks types be determined, and the existence and distribution of sediments system are dominated by volcanic provenance,the normal clastic provenance derived from recycled sediments, affected by granite, affected by granite and volcanic rocks together,and mixed provenance in Member 1Y-V of Yingcheng Formation in Shiwu oilfield.