ANALYSIS OF SILURIAN RESERVOIR-FORMATION CONDITION IN TAHE OILFIELD

Tahe oilfield is geographically located at Kuche and Luntai county in Xinjiang Uigur Autonomous Region.It is structurally located at the southwestern slope of Akekule salient in Shaya uplift in Tarim basin.Because of the effects that are caused by late Caledonian event,early Hercynian movement,late Hercynian movement and early Yanshan movement,Silurian System,Devonian System,upper Carboniferous,Permian System and middle-upper Jurassic System are absent in the main part of Akekule salient and in a majority of south slope of Akekule salient.In addition,upper-middle Ordovician is denuded to some extent and is absent in part areas.The Silurian System is absent in most part of Tahe oil field.At present,the Silurian System is mainly met at the southwestern part of Tahe oil field and it mainly is Kepingtage group(S₁k)and Tataaiertage group(S₁t).The analyses of source rocks,reservoir bed,caprock and trap indicate that the Silurian System in Tahe oil field and its surrounding areas mostly belong to stratum-lithology and stratum-structure composite traps which are mostly connected with stratum truncation or overlap pinching out and a few of them are structural trap and lithologic trap.Researches show that the Silurian System possesses the conditions forming oil and gas accumulation.