油气藏内烃类再运移及原油性质的改造

SECOND MIGRATION OF HYDROCARBON AND REFORMING OF PETROLEUM QUALITY IN AN OIL OR GAS POOL

在油气藏形成之后所经历的地史过程中 ,构造运动使其圈闭条件有不同程度的改变 ,油气藏中的烃类发生再运移 ,从而造成油气藏的破坏再形成 ,或者使其遭到彻底破坏。油气藏的变化使烃类的性质也产生变化 ,如生物降解作用使原油稠化 ,或地热作用使其发生热裂解而成气。对 3种油样进行的热裂解成气模拟实验结果表明 ,地温条件、压力和时间对原油裂解成气均有明显的影响。对克拉玛依油田和孤岛油田原油中细菌成活情况的检测结果表明 ,细菌生长的最佳温度是 30℃ ,最佳生长环境是淡水及pH为 7的地层水。原油被菌解后 。

In the changing process of tectonic type after formation of oil and gas reservoir, tectonism can translate the geological conditions in some extent. Second migration of hydrocarbons results in damage\|reformation or thorough damage of oil and gas reservoir. At the same time, the properties of hydrocarbons may be changed with the change of oil and gas reservoir. For example, biodegradation makes oil thickened and hydrocarbons generate pyrolysis gas under the geothermal action. Thermal simulating test of three oil samples to generate pyrolysis gas shows that geothermal temperature, pressure and time have obvious influences on generation of pyrolysis gas. The biodegradation tests of oils from Karamay oilfield and Gudong oilfield show that the physical and chemical properties of oils are changed after oil biodegradation. The optimum temperature for growth of bacteria is 30 ℃, and the best environment for it is in pure water and formation water with pH value of 7.0.