Study Of Favored Oil And Gas Bearing Structure In Tazhong Area

Tarim basin is the biggest petroliferous basin in our country, it's area is about 560 thousand sq.km. Exploration have proved it contains abundance oil and gas resource and prospective exploration future. Many progression have been obtained in Ta zhong area since 1989, seven reservoirs have been found.but with time passed,the trap explored easily become more and more difficult ,and so it is necessary to find new stratum and new type trap for abundance resource in the future, at present, Silurian-Devonian stratum possess prospective exploration foreground.The topic of this paper is structure, firstly analyse the earth structure setting of Tarim basin and tectonic evolution of Tazhong area in Silurian-Devonian, and give Silurian-Devonian stratum control and effect, then study the relationship of the development of Tazhong uplift, fracture unconformity igneous rock and and oil-gas, at last, on the base of the analyse about history of reservoirs formation, forecast reservoirs pattern, point out favored oil and gas bearing structure and the target. And obtain some important conclusion.1. Tarim basin became initiative continent margin in Silurian-Devonian,it collided with middle Kunlong island arc and middle Tianshan island arc on the north and south, ancient uplift developed further and formed, and produced abundance fracture and unconformity.2. Tazhong ancient uplift originated from normal fault in Paleozoic, hydrocarbon formed in Ordovician period, structure reverse made Tazhong uplift form from the middle Ordovician period to the late Ordovician period, and it provided geologic background for the deposit of Silurian-Devonian stratum. Tazhong uplift formed at the end Devonian, ancient reservoir was destroyed and asphaltum sandstone formed, structure deformation more destroyed ancient reservoir in early Permian, after then the major of structure deformation is regulation.3. Fracture and unconformity don't controlled distribution of structure bearing, but the distribution of oil-gas, composed network channel for oil-gas move, and formed a large of trap.4. three stages of hydrocarbon happened in Silurian-Devonian stratum.5. Structure control hydrocarbon accumulation of Silurian-Devonian stratum.6. Tazhong 10 structure bearing etc. are favorable structure.