徐深气田火山岩岩性岩相序列

火山岩岩相变化快、物性变化大、储层非均质性强，因而弄清其岩性岩相序列是高效开发火山岩气藏的前提。通过野外露头精细勘测以及徐深1、升深2 1等开发区密井网解剖，在对露头与钻井取心资料分析的基础上，提出了松辽盆地徐深气田火山岩综合命名方法。通过火山岩露头岩性岩相序列特征研究，井震结合，建立了徐深气田下白垩统营城组火山岩岩性、岩相序列，揭示了徐深气田营城组火山岩的分布特征。其中，岩性序列自下而上为中基性岩、火山碎屑岩、酸性岩→沉积岩→火山碎屑岩、基性岩、酸性岩→沉积岩4大套旋回序列；徐深气田火山岩岩相主要为溢流相的上、下部亚相和爆发相的热碎屑流亚相。该方法对类似的火山岩气藏岩性岩相序列特征研究具有借鉴作用。

Lithologic and lithofacies sequences of volcanic rocks in Xushen gas field

Due to the rapid change of volcanic lithofacies, a large variation of physical properties and the strong heterogeneity of reservoirs, it is essential for the highly efficient development of volcanic reservoirs to make clear the lithologic and lithofacies sequence. Therefore, we performed a detailed outcrop observation and analyses of many well data in the wellblocks like Xushen 1 and Shengshen2 1, etc. According to outcrop and core data analysis, we presented a comprehensive naming method for the volcanic rocks in the Xushen gas field, Sonliao Basin. Upon the study of the lithologic and lithofacies sequence characteristics and correlation of well data with seismic data, we established the lithologic and lithofacies sequences for the volcanic rocks in the Lower Cretaceous Yingcheng Formation in the Xushen gas field, and revealed the characteristics of their distribution. The lithologic sequence consists of 4 cyclic sequences including, from bottom to top, ①intermediate basic volcaniclastic acidic rocks, ②sedimentary rocks, ③volcaniclastic basic rocks acidic rocks, and ④sedimentary rocks. The lithofacies mainly include the upper and lower subfacies of the effusive facies and the pyroclastic bearing lava flow subfacies of the eruptive facies. This naming method can be used as a reference for the study of lithologic and lithofacies sequences in similar volcanic gas reservoirs.