普光地区飞仙关组颗粒滩储层发育分布规律及控制因素

Development and distribution of grain shoal reservoir of the Feixianguan Formation in Puguang area and controlling factors

宿亚仙

SU Yaxian

中国石化中原油田分公司勘探开发研究院，河南 濮阳 457001

Exploration and Development Research Institute, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China

四川盆地二叠系—三叠系白云岩储层广泛发育，发现了普光、元坝、罗家寨等一系列大中型气田，但深层海相碳酸盐岩储层的规模和非均质性却成为限制深层油气藏勘探开发的关键因素之一。综合普光地区飞仙关组钻测井、岩心、岩石薄片、碳氧同位素等资料的研究发现：飞仙关组储层岩石类型主要为（残余）鲕粒白云岩、晶粒白云岩；储集空间类型主要为粒内溶孔、粒间（溶）孔、晶间（溶）孔、溶洞。其中，粒内溶孔平面上主要发育在古地貌高地，垂向上发育于旋回上部。飞仙关组优质储层形成与保存受控于高能鲕粒滩沉积、溶蚀作用、白云岩化作用和较好的保存条件。飞仙关组储层的非均质性主要与颗粒滩原始沉积和后期成岩有关，古地貌和海平面升降控制了储层平面和垂向的非均质性，古地貌较高区域以厚层高能鲕粒滩沉积为主，遭受较强的准同生溶蚀和白云岩化作用，具备较强的孔隙保存能力，现为优质储层。该研究进一步落实优质储层的分布，丰富普光气田滩相储层非均质性方面的研究成果，对相似碳酸盐岩储层的研究提供借鉴。

The Permian-Triassic dolomite reservoir has been extensively developed in the Sichuan Basin, and a series of large and medium-sized gas fields such as Puguang, Yuanba and Luojiazhai have been discovered. However, the scale and heterogeneity of deep marine carbonate reservoirs has become one of the key factors limiting the exploration and development of deep oil and gas reservoirs. Based on the data of drilling and logging, core, thin section and carbon and oxygen isotope, it is found that the main rock types of the Feixianguan Formation are (residual) oolitic dolostone and crystalline dolostone. The reservoir space types in Puguang area are mainly  intragranular dissolved pore, intergranular (dissolved) pore, intercrystal (dissolved) pore and karst cave. The intragranular dissolved pores are mainly developed in the palaeogeomorphic highlands and vertically in the upper part of the cycle.  The formation and preservation of the high-quality reservoir of Feixianguan Formation is controlled by high-energy oolitic shoal deposition, dissolution, dolomitization and good preservation conditions. The heterogeneity of the reservoir is mainly related to the original sediment of grain shoal and later diagenesis, and the paleogeomorphology and sea level rise and fall control the reservoir heterogeneity horizontally and vertically. The higher paleogeomorphic area was dominated by thick high-energy oolitic shoal deposits, which were more likely to suffer from strong penecontemporaneous dissolution and dolomitization and had strong pore preservation ability, and still retained high-quality reservoirs today. The research can further identify the distribution of high-quality reservoirs and enrich the results on the heterogeneity of carbonate shoal reservoir in Puguang gas field, and provide reference for the study of similar carbonate reservoirs.

10.6056/dkyqt202303006