Geochemistry Characters Discussion And Convergency Analysis For Oil And Gas Of Baise Basin

Baise Basin is on the southwest of Guangxi Zhuang Autonomous Region. It extends from north to west like a strip. The basin is 109 kilometers long, 2～14 kilometers wide, and the area is 830 sq. km. It is a representative bequeathed basin. The natural gas and oil in this basin has been reconnoitred for about 70 years. And it has high reconnoitred degree. From now on, people have found 3 shallow dense oil resources , 7 oil fields and a lot of oil effusing point in Baise Basin. Now we know there are 1233 X 104t reconnoitred reserves, 267×104t controlled reserves, 77×108 m~3 shallow natural gas reserves and Leigong and Shangfa gas resources in the basin. Baise is the best third system basin in the region.This thesis expatiates the oil geochemistry characters and partitions the cause of form by studying the rock samples of Baise. And it discusses the oil moving and collecting characters by contrasting oil and rock. This thesis also analyses the geochemistry characters of shallow gas and studies how the gas becomes resourses. At last it advances five plummy zones for reconnotiring.We know that the oil in Baise can be divided into four styles according to the research. First, the oil of Jiangze and Baise in west col; second, the oil of Tianyang,Nakun,Sanjin and part of Huacha in the west of east col; third, the oil of Tangzhai,Lunxu,Ziyin,Shangfa in the center and east of east col; forth, the oil like Lun 4 of Huacha field. The thesis discusses that the oil geochemistry datas and the oil distributing in region are identical. That indicates oil collecting is near the fountainhead. The oil in the center and east of east col is mainly from the lake and high water level stratum near it. Maybe little from the low water level. But the oil in west col and the wast of east col is mainly from low water level stratum.The shallow gas is similar to Baigang group and Nadu group mud rock in carbon isotope composing of firedamp. But different to coal. So we consider that biology firedamp is mainly from mud rock. But the heavy hydrocarbon of shallow gas is same to the mud rock of Nadu group and the light hydrocarbon of coal. This explaines that the heavy hydrocarbon of shallow gas is mainly from fountainhead rock of Nazu group. The distributing of press decides the oil moving direction. And at the same time the direction is restricted by the distributing of liquid. The main representation is that the high move to the low, and the center move to the margin. The plummy zones for reconnotiring are the center of Tiandong col,Zisan-liuchou-nayang system of the north steep slope,Nabi heave,the center of west col and Liutang col,the south shallow slope of Tiandong col and the center of Toutang col.