Experimental Study On The Origin Of Oil And Gas In Deep Parts Of The Baxian Subsags

Huabei oilfield deep exploration has made great breakthrough in recent years, butthere is not a reasonable explonation to the Origin of deep hydrocarbon in the BaXiansubsags. So we select appropriate hydrocarbon source rocks for the gas-producedexperiments of source rock pyrolysis and crude oil cracking under the closed condition ofhigh temperature and high pressure. Through analysis their hydrocarbon generationmechanism, we set up the identify template of the different gases from source rockpyrolysis and those from crude oil cracking.At last we made a reasonable explanation andpositioning suitable for the origin of crude oil in the well Niudong-1.Select four groups light hydrocarbons of the gas obtained from the experiment as anindex,then use this index to identify the origin types of the gas in the well Niudong-1. Alllight hydrocarbon parameters of the gas in the well Niudong-1fall within the area ofhydrocarbon source rock pyrolysis gas, so make sure the origin of hydrocarbon source rockpyrolysis. By Mango parameter confirm, diamantane analysis and lighter hydrocarbonindex calculation, we consider that the gas in the Well Niudong-1is high-maturity at about1.8%. and the light oil and gas have homologous characteristics.The oil and gas generation models of the bottom in the Shehejie formation in deepparts of the BaXian subsags is also an important aspect of our study. Select hydrocarbonsource rock with Ⅱ1type of organic matter for thermal simulation experiment, thenconduct a contrast research on hydrocarbon generation models and the lower exist limit ofliquid hydrocarbon in the BaXian subsags. Based on the thermal simulation experiment forthe origin of deep oil and gas, we combine with the burial history to further explore andimprove the models.Make hydrocarbon generation kinetics analysis on hydrocarbon source rocks samplesin the BaXian subsags by oil and gas evaluation workstation(OGE-VI). We find that thedegradation of organic matter is inversely proportional to the heating rate, and the minimum activation energy of organic matter degraded is in the vicinity of230Kj/Mol. Inthe area that the activation energy lies between230Kj/Mol and360Kj/Mol, about80%ofthe organic matter is degraded, meanwhile the hydrogen index and hydrocarbon generationrate are higher than other activation energy intervals. and in the area that the activationenergy is larger than680Kj/Mol, a lot of organic matter still did not degrade, it is alsoproved the huge potential of liquid hydrocarbon in the super deep region.