The Development Of Fluid Pressure And The Relationship Pressure Development And Pool Forming Process In Upper Paleozoic Of Tabamiao Area, Ordos Basin

The abnormal pressure in Petroliferous basin is an universal important geological phenomenon. The characteristics of universal low abnormal pressure, tight reservoirs, simple tectonics, dispersed gassy beds, complicated mechanism of gas accumulation in upper Paleozoic of Ordos Basin. Under this circumstance, Tabamiao area is selected as a target area. Geologic factor of fluid pressure forming is analyzed. Based on this, compaction study and calculation of engender pressure of fluid pressure used as a basic method, geologic theory of basin forming, hydrocarbon generation and hydrocarbon accumulation used as guidance, We recovery pressure evolution model and construct the model of oil and gas accumulation in study area. Main cognitions and research results are as follows:(1) Through quantitative calculation of pressure and synthetical analyse It is indicate through quantitative calculation of pressure and synthetical analyse that:â‘ under-compaction is the main factor of high pressure on non-source rocks in the compartments at present;â‘¡hydrocarbon generation is the main factor forming ancient high pressure in the source rocks;â‘¢hydrothermal condition has dualism;â‘£geotemperature falling in tectonic uplift-denudation and the later period and sandstone "springback" are the main factors resulting ancient high pressure dropping in the reservoirs. At present.(2) Geologic factor of fluid pressure forming is analyzed. Based on this, compaction study and calculation of engender pressure of fluid pressure used as a basic method, geologic theory of basin forming, hydrocarbon generation and hydrocarbon accumulation used as guidance, We recovery pressure evolution model and construct the model of oil and gas accumulation in study area. Three key phases of pressure and hydrocarbon pooling are put forward(3) The thoughts are put forward first through the reseach on the shape and inside structure in the pressure compartments: there are different shapes in different pressure compartments in the areas and the position of the biggest surplus pressure controlled the distribution of main gas layers; the inside structure in the pressure compartments could be subdivided into three types which delegated the different petroleum system: typeâ… is the best gas potentials, typeâ…¡is in the middle and typeâ…¢is poor in gas potentials;(4) The models of the hydrocarbon pooling is established on the basis of the above research combing with the characteristics that the natural gas is controlled by the pressure compartment and systematic theory of petroleum geology.