Study on Sedimentary Facies and Reservoir Characteristics of Paleogene Sandstone in Yingmaili Block, Tarim Basin

Table 1

Summary of formations of Yingmai 7 gas field.

Formation						Thickness, m	Lithology	Sedimentary facies
Tie	Unify	Group		Section	Sub
Quaternary Q	—	—		—	—	106~135	Interbedded light gray loose sand, variegated gravel, and grayish-yellow clay	—
Neogene N	Pliocene	Kuqa Group		—	—	2773~2824	Thick to extremely thick layered mudstone and medium to thin layered fine sandstone, calcareous siltstone, siltstone, and argillaceous siltstone are interbedded with unequal thickness. Diagenesis increases gradually from top to bottom	—
	Miocene	Kangcun Group		—	—	802~858	Medium-thick to superthick layered brown, gray-brown, brown-gray, gray mudstone, siltstone mudstone, and thick to medium-thick layered light gray. The brown-gray siltstone and argillaceous siltstone are interbedded with slightly equal thickness to unequal thickness	—
		Giddick Group		—	—	672~722	Medium-thick to superthick layered blue-gray, gray, brown, gray-brown mudstone, silty mudstone, gypsum-bearing mudstone, light gray, brown-gray siltstone, and argillaceous siltstone are interbedded in unequal thickness	—
Paleogene E	Oligocene-Paleocene	Suwei Formation–Kumglimu Group		Gypsum mudstone section	—	200~228	The upper part is medium-thick-thick layered brown-red gypsum mudstone, and the mudstone is interbedded with light brown silty mudstone. The lower part is thick layered white salt rock, gypsum rock and purple mudstone, brown gypsum mudstone, and gray-brown argillaceous siltstone interbedded	—
				Bottom sandstone section	E1	6 ~ 9	Medium-thick to thick layered light gray gypsum siltstone, fine sandstone, and brown fine sandstone, with thin layers of purple-red mudstone	Lake phase
					E2	7 ~ 14
Cretaceous K	Lower	Bashkichik Group		—	K1	21~26	Thick to medium-thick layers of brown, light brown, yellowish-gray fine sandstone, and siltstone are mainly interspersed with thin layered brown mudstone and silty mudstone, and thin brown mudstone conglomerate is locally distributed	Braided delta
					K2	15~20
					K3	34~33
		Kapsaryan Group	Baxigai Formation	—	—	—	—	—
			Shushanhe Formation	—	—	—	—	—
			Sublime Formation	—	—	—	—	—