The PVTX Modeling Of The Hydrocarbon Inclusion And Its Application In Songliao Basin Of North Qijia Region

It is very difficult to determine the formation fluid pressure (palaeopressure) of geological history in geologic study. As the trapping pressure of hydrocarbon inclusions are important data to reflect the depth of oil reservoir and fluid pressure conditions in the reservoir, the approach of using the isochore equations of both hydrocarbon inclusions and the aqueous inclusions associated with hydrocarbon inclusions to calculate the trapping temperature and pressure of inclusion in the reservoir formation. It can provides an independent approach to calculate temperature and pressure of reservoirs formed more accurately.Based on the further study of hydrocarbon inclusions, according to the phase evolution figure of various hydrocarbon inclusions and testing results of parameters of fluid composition of immiscible hydrocarbon inclusions, density, homogenization temperature, gas liquid ratio and molar volume through careful measurement to calculation in the simulation. According to the principle of phase equilibrium establish phase diagram of the immiscible system, then the capture temperature(T)and pressure(P)of inclusions can be inferred. Combining the burial history of the south area of Qijia in Songliao Basin helps determine the buried depth of formation of hydrocarbon inclusions and corresponding geological era and determine the hydrocarbon accumulation period.The result shows that there are four hydrocarbon charging histories in the north area of Qijia of Songliao Basin in hydrocarbon reservoirs. Corresponding the temperature range from early to late respectively are: 60～90℃;120～140℃;160～170℃;180～200℃.With the capture temperature and pressure of two representative samples of inclusions to take a PVTX simulation calculation by using simulation software, the trapping temperature and pressure of the aqueous inclusions associated with hydrocarbon inclusions are:81.5℃,12.86MPa ; 86.5℃,14.19MPa respectively.Combining the burial history of the reservoir of the north area of Qijia, using the capture pressure of petroleum inclusion to calculate the filling period of the oil and gas. It can be inferred that the main time hydrocarbon accumulation is between 72-67Ma in the the north of Qijia Region, and the sedimentary period is from Mingshui group late to Sifangtai group.The depth of oil reservoir in member-one of Qingshankou is vary from 1308.37 to 1539.36 mainly.