非常规气藏有利岩性组合定量模拟及测井识别

Quantitative Modeling and logging Identification of Favorable Lithology Association in Unconventional Gas Reservoir

致密油气藏作为非常规能源的勘探热点之一,其成藏机理及富集规律一直备受关注。川西须五气藏为介于页岩气和致密砂岩气之间的非常规气藏,储层砂岩致密,非均质性强,泥页岩发育,其地层岩性组合是较为关键的成藏因素之一。为了对该类气藏的岩性组合特征进行有效评价,在已有测井数据的标定下,利用测井资料划分砂泥岩剖面后,对测试段的砂泥比、砂地比、互层率及4类砂岩层数占比等指标参数进行定量模拟计算,建立了有利岩性组合测井识别模式。研究表明,该方法高效快速、分辨率高,为该类非常规油气储层评价提供了有效参考,并在川西新场地区须五段地层获得了较好的应用效果。

Tight hydrocarbon reservoir is considered as a highlight in unconventional hydrocarbon exploration and its hydrocarbon accumulation and enrichment have been highly concerned. Xuwu gas reservoir is considered as an unconventional gas reservoir between shale gas and tight gas,which is characterized by tight sandstone reservoir,strong heterogeneity and well-developed shale. The stratum lithology association is one of the most significant factors for hydrocarbon accumulation. In order to effectively evaluate the lithology association properties,available logging data is used to divide mudsand section based on the calibration of previous logging data. The sand-mud ratio,net-gross ratio,interbedding ratio,ratio of 4-class sandstones and other parameters are quantitatively modeled and calculated to establish the logging identification mode of favorable lithology association. Research shows that this method with fast and accurate performances could provide certain reference for unconventional hydrocarbon reservoir evaluation and has been effectively applied in Xinchang Xuwu formation of western Sichuan.